Path Flashcards

Question

What is the LRINEC Scoring system?

Answer 1

Used to diagnose necrotizing fasciitis. score \> 6 has PPV of 92% of having necrotizing fasciitis.

Answer 2

Eosinophilic granuloma Slide show Langerhans cells which have eosinophilic cytoplasmic cells that are mononuclear with a coffee bean shaped nuclei.

Answer 3

Lyme disease The slide is of borrelia burgdorferi. Spirochete transmitted by the deer tick Ixodes.

Answer 4

Acid fast staining Mycobacterium tuberculosis

Answer 5

True False, they are relatively uncommon. False, they are associated with a fair rate of healing.

Answer 6

Radionuclide bone scan is unreliable. As these are lytic lesions and 3-50% of the time will be "cold" or siltent on scan. Perform a skeletal survery instead.

Answer 7

Multiple Myeloma 67%

Answer 8

False False

Answer 9

Pelvis Second, Scapula. Proximal lesions more likely to undergo malignant transformation.

Answer 10

Another name for Enneking staging system. Two systems one for malignant (roman numerals) one for benign lesions (arabic numerals).

Answer 11

Used more for soft tissue tumors. Depends on: grade- low = G1 and G2. High= G3 and G4. size- T1 = \<8cm T2 = \> 8cm nodes- N0 = no regional nodes N1 = Regional nodes Metastasis- presence of distant metastasis automatically elevates patient to stage IV disease.

Answer 12

Aggressive bone or soft tissue lesions Soft tissue lesions larger than 5cm, deep to fascia, or overlying bone/neurovascular structures. Unclear diagnosis in a symptomatic patient Solitary bone lesions in a patient with history of carcinoma

Answer 13

incision should be longitudinal in the extremities and allow for extension for definitive management. Do note expose neurvascular structures. All tissue exposed during biopsy is considered contaminated with tumor. This goes for post-operative hematomas as well. Peform through only the involved compartment If using a drain bring drain out of the skin in line with surgical incision.

Answer 14

anthracycline antibiotic commonly used in oncological protools Functions as a cytostatic agent. Cardiac toxicity. Leads to congestive heart failure **Dexrazoxane** used to mitigate toxicity.

Answer 15

Osetosarcoma (intramedullary and periosteal) Ewing's sarcoma/primative neuroectodermal tumor Malignant fibrous histiocytoma Dedifferentiated chondrosarcoma (**chemotherapy for soft tissue sarcoma is controversial)**

Answer 16

Give sodium thiosulfate Give hot compress and hyaluronidase. Give cold compress for all other vesicants(agent that causes blistering).

Answer 17

Ewing sarcoma/primative neuroectodermal tumor Primary Lymphoma of bone Hemangioendothelioma Solitary plasmacytoma of bone

Answer 18

Soft tissue sarcomas GI and renal tumors. Prostate tumors are very radiosensitive.

Answer 19

1 rad = 1 centiGray Typical dose is 180-200 cGy/day Radiotherapy is cumulative Total dose: \< 45 Gray: usually leads to uncomplicated tissue healing. 45-55 Gray: tissue usually heals but with problems. \> 60 Gray: tissue unlikely to heal.

Answer 20

13% More frequent in patients with prior chemotherapy.

Answer 21

25% following soft tissue sarcoma resection and external beam irradiation. Total rod dose \>59gy Weight bearing bones Female Osteoporosis Age Periosteal stripping Anterior femoral compartment resection Volume of bone receiving it.

Answer 22

Males 3:1 \> 80% present before age of 30.

Answer 23

Lower extremity \> 50%. Proximal femur \> tibia diaphysis Spine 10-15% Hand 5-10% Foot \<5%

Answer 24

Increased local concentration of prostaglandin E2 and COX1 & 2 Expression Increased number and size of unmyelinated nerve fibers within the nidus.

Answer 25

Pain usually resolves after an average of 3 years The lesion spontaneously resolves in 5-7 years In the spine, early resection (within 18 months) leads to resolution of scoliosis in young children (\<11 years).

Answer 26

Osteoblastoma

Answer 27

Any lesion that is close to skin or a nerve. Spine lesions assoicated with painful scoliosis. Spine lesions that are close to the cord or nerve roots. Digital lesions- RFA carries risk of thermal skin necrosis and injury to digital neurovascular bundle

Answer 28

Males \> Females 2:1 Majority of patients 10-30 years of age Most common in posterior elements of spine

Answer 29

oncogenic osteomalacia 10-40% associated with secondary ABC

Answer 30

lytic or mixed lytic-blastic with a radiolucent nidus that is \> 2cm. 66% cortically based and 33% medullary based Often expansile with extension into soft tissues with rim of reactive bone. Need CT to fully evaluate lesion.

Answer 31

Similar to osteoid osteoma but with more giant cells. Distinct demarcation between nidus and reactive bone. Nidus of immature osteoid and osteoblasts with abundant cytoplasm and normal nuclei

Answer 32

Curettage or marginal excision with bone grafting is standard of care. Recurrence 10-20% Observation is rarely if ever indicated as the lesion will continue to grow

Answer 33

Metastatic disease Myeloma Intramedullary osteosarcoma

Answer 34

Bimodal distribution: majority occur in the second decade of life. Second peak in occurrence is in elderly patients with Paget's disease Most common sites: distal femur\>proximal tibia\>proximal humerus\>proximal femur\>Pelvis\>axial skeleton

Answer 35

Lung is the most common site of metastasis. 10-20% of patients will present with pulmonary metastases. Bone is the second most common site.

Answer 36

AR inheritance. Mutation in RECQL4 gene, chr 8q24.3 Sun sensitive facial poikiloderma rash (pigmentation, thined skin, prominent blood vessels) Absent eyelashes, eyegrows, hair Juvenile cataracts, teeth abnormailities Osteosarcoma, fibrosarcoma, gastic adenocarcinoma, cutaneous BCC and SCC

Answer 37

76% long term survival with modern treatment. Advanced stage of disease **(most predictive of survival)** Response to chemotherapy (judged by percent tumor necrosis of resected speciment) Tumor site and size Expression of P-glycoprotein, High serum alkaline phophatase, high lactic dehydrogenase vascular involvement, surgical margins, type of chemotherapy regimen.

Answer 38

Blastic and destructive lesion. Sun-burst or hair on end patternof matrix mineralization . Periosteal reaction (Codman's triangle). Large soft tissue mass with maintenance of bone cortices.

Answer 39

MRI: must include entire involved bone to determine soft tissue involvement, neurovascular involvement, and presence of skip metastases. BONE SCAN: very hot in osteosarcoma. Useful to evaluate extent of local disease and presence of bone metastases. CT: Chest CT required at presentation to evaluate for pulmonary metastases.

Answer 40

Alkaline phophatase may be 2-3 times normal.

Answer 41

Tumor cells show significant atypia and produce "lacey" osteoid. Stroma cells show malignant characteristics with atypia, high nuclear to cytoplasmic ratio, and abnormal mitotic figures. Giant cells may be present in giant cell rich osteosarcoma and can be confused with giant cell tumor of bone. May have mixed histology with different combinations of chondroblastic osteoblastic, or fibroblastic looking cells.

Answer 42

multi-agent chemotherapy and limb salvage resection. Pre-operative chem for 8-12 weeks forllowed by maintenance chemotherapy for 6-12 months after surgical resection. Survival is equivalent after limb salvage vs amputation. Can do wide surgical resection alone for low grade osteosarcoma. Amputation is indicated if there is a pathologic fracture, encased neurovascular bundle, or if the tumor is enlarging during preop chemo AND adjacent to a neurovascular bundle.

Answer 43

Females age 30-40 Occurs on surface of metaphysis of long bones. Most common sites include posterior distal femur (80%), proximal tibia, and proximal humerus.

Answer 44

False 95% long term survival when local control has been achieved. Dedifferentiation of parosteal osteosarcoma is a poor prognostic factor

Answer 45

Painless mass Limiting joint motion can also be a presenting complaint for characteristic large posterior distal femoral lesions.

Answer 46

Heavily ossified, lobulated mass arising from cortex. Appears stuck onto cortex. CT chest to look for mets. MRI of entire bone. Bone scan is mandatory. Will always be hot.

Answer 47

Wide local surgical excision is standard of care. Chemotherapy not indicated unless there is a high grade component.

Answer 48

15-25 years of age, more common in females. Occurs most commonly in the diaphysis of long bones. Femur and tibia are most common. Pain is the most common presenting symptom. 25% present with a pathologic fracture.

Answer 49

Intermediate. Better than intramedullary, but wors than parosteal. 20-35% chance of pulmonary metastases.

Answer 50

classic "sunburst" or "hair on end" periosteal reaction. Often occurs in an areas of saucerized cortical depression. CT scan, Bone scan (very hot), and MRI.

Answer 51

gross tumor appears lobular and cartilaginous Chondroblastic matrix on slide. Tumor still produces osteoid though. **If no osteoid is produced the tumor would be classified as a chondrosarcoma.**

Answer 52

Same as intramedullary. Multi-agent chemotherapy and limb salvage resection. 8-12 weeks pre-op chemo. 6-12 months of chemo after resection.

Answer 53

Tumor suppressor genes: Rb-1 and P53 Oncogenes: HER2/neu, c-myc, and c-fos

Answer 54

Epidemiology and genetics is similar to classic osteosarcoma. Male \> Female Presentation is similar to ABC. Proximal humerus, proximal femur, distal femur, and proximal tibia are the most common locations. **Prior radiation is a risk factor.**

Answer 55

Poor. More chemosensitive than intramedullary osteosarcoma but similar survival. 5 year survival with tumor localized to an extremity is 70% 5 year survival with metastases is 20%

Answer 56

Radiographs will show a lytic, expansile, destructive lesion where the entire cortex may be compromised. Need bone scan and MRI. MRI will show fluid-fluid levels and extensive edema in surroudning tissue. Notable that a CT is not required, but will likely be obtained.

Answer 57

High grade sarcoma with mitotic figures is seen in intervening cellular areas. Lakes of blood mixed with malignant cells (not in ABC). Not as much osteoid as intramedullary osteosarcoma.

Answer 58

Diagnosis is difficult and needs to be confirmed by an experience musculoskeletal pathologist. Key is histology that shows the presence or absence of malignant cells with mitotic bodes.

Answer 59

Multi-agent chemotherapy and limb salvage resection.

Answer 60

Hands 60% of the time Most common bone tumor of the hand. Other locations femur (20%), Proximal humerus 10%, and tibia. **Rare in the pelvis, scapula, and ribs. Suspect condrosarcoma in these locations.**

Answer 61

chondroblast fragments of the epiphyseal cartilage escape from the physis and displace into the metaphysis and proliferate there. 2nd most common benign cartilage lesion (osteocondroma is the most common).

Answer 62

Multiple enchodromatosis) Sporadi inheritance with no genetic predispostion. Enchondromas throughout the metaphyses and diaphyses of long bones- involved bones are dysplastic, with shortening and bowing. **risk of malignant transformation \<30%**

Answer 63

Multiple enchondromas and soft tissue angiomas Radiographically enchondromas in Maffucci's syndrome markedly expand the bone and angiomas are seen as small, round calcified phleboliths. **risk of malignant transformation up to 100%** **also has increased risk of visceral malignancies (astrocytoma, GI malignancy)**

Answer 64

True Unlike enchondroma, most chonrosarcomas have non-mechanical pain (rest pain and nocturnal pain)

Answer 65

1-10 cm in size Pop-corn stippling, arcs, whorls, rings Minimal endosteal erosion (\<50% width of cortex) Cortical expansion may be present in hands and feet but not in femur or tiba May have a purely lytic appearanc eespecially in hand. **Chonrosarcoma's display cortical thickening and destruction. endosteal erosions and scalloping \>50% of the width of the cortex. Usually are larger (\>5cm)**

Answer 66

Enchondroma on MRI has high T2 signal because of high water content of cartilage. Bone infarct low signal on T2.

Answer 67

Bone scan: enchondromas will have increased uptake but are small and have less uptake than chondrosarcoma. MRI: Enchondroma will have no bone marrow edema or periosteal reaction. Medullary fill \>90% suggests chondrosarcoma instead of enchondroma.

Answer 68

SOLITARY LESIONS IN LONG BONES: hypocellular with bland, matrue hyaline cartilage (blue balls of cartilage) separated by normal marrow. SOLITARY LESIONS IN SMALL TUBULAR BONES AND FIBULA, OLLIER'S, AND MAFFUCCI'S: Hypercellular with mild chondrocytic atypia. **Chondrosarcomas display:** Hypercellularity, with plump nuclei. Multiple binucleate cells, and giant cells with clumps of chromatin.

Answer 69

Observation for vast majority. Serial radiographs at 6 months and 12 months to confirm radiographic stability. Long term follow-up for patients with multiple enchondroma syndromes. INTRALESIONAL CURETTAGE AND BONE GRAFTING: Lesions that show any change on serial x-rays. Symptomatic lesions. Pathologic fractures (**immediate curettage and grafting is now favored**). Large lesions at risk for recurrent fracture. **Local recurrence is unusual.**

Answer 70

Rare chondroma that occurs on surface of long bones. Occurs in 10-20 year olds. 59% of lesions in proximal humerus. Also distal and proximal femur. Can be seen in metacarpal or phalanges. RADIOGRAPHS: well demarcated shallow cortical defect. saucerization of underlying bone. HISTOLOGY: Similar to enchondroma but increased cellularity and more malignant looking cells. TREATMENT: For those that are painful and interferring with function. Marginal excision including underlying cortex. Bone graft large defects. Will recur if cartilage is left behind.

Answer 71

On the surface of bones and often at sites of tendon insertion Knee Proximal femur Proximal humerus Subungal exostosis (occurs most often at hallus)

Answer 72

Salter-Harris fracture Surgery Radiation therapy

Answer 73

\<1% with solitary osteochondroma 5-10% with MHE develop secondary chondrosarcoma When it does occur it is a **secondary chondrosarcoma:** Most commonly a low grade tumor (90%) Occurs in older patients, 50 or older. Rare in pediatric population. Most common location of secondary chondrosarcoma is the pelvis.

Answer 74

Multiple osteochondromas Autosomal dominant Mutation in EXT1, EXT2, and EXT3 tumor suppressor genes. Leads to decreased production of heparin sulfate by chondrocytes found at the physis. EXT1 is mor severe than EXT2. 5-10% risk of malignant transformation to chondrosarcoma. Proximal lesions more likely to undergo this transformation.

Answer 75

Ulnar shortening and radial bowing. Radial head dislocation Ulnar deviation of the hand.

Answer 76

Acue onset of pain in adults with MHE.

Answer 77

Sessile (Broad base)- Higher risk of malignant degeneration Pedunculated (Narrow stalk)- Pain away from the joint. Have a cartilage cap that is usually thin. If cartilage cap becomes thicker as an adult, need to be concrned for chondrosarcoma transformation.

Answer 78

Only if they become symptomatic. Surgical excision inculding the cartilage cap. Try to delay sugery until skeletal maturity.

Answer 79

epiphyseal lesion in young patients Usually agound 12 years of age. 80% of patients under 25 years of age. M:F = 2:1 Common locations include distal femur and proximal tibia \>\>\>proximal humerus, proximal femur, calcaneus, flat bones, and apophysis or triradiate cartilage of the pelvis. \<1% develop benign pulmonary mets Local recurrence rate is 10-15% **painful**

Answer 80

Well-cricumbscribed epiphyseal lytic lesion with thin rim of sclerotic bone Lesions often cross physis into metaphysis Stippled clacifications within the lesion may be present. Cortical expansion may be present. **soft tissue expansion is rare.**

Answer 81

Chondroblasts arraged in "cobblestone" or "chickenwire" pattern Scattered multinucleated giant cells with focal areas of chondroid matrix **Mononuclear stromal cells are distinct. Large central nuclei. Nuclei have longitudinal groove resembling coffee bean.** **S100**+ 1/3 of chondroblastomas have areas of secondary ABC

Answer 82

Extended intralesional curettage and bone grafting. May do adjuvant treatment with phenol or cryotherapy to decrease local recurrence. Surgical resection if there are pulmonary mets.

Answer 83

Most common in second and third decades of life. More common in males. Often affects metaphyseal regions of long bones. Tibia and distal femur most common. Can also be in the pelvis, feet, or hands. Genetic rearrangement that may affect chromosome 6 (position q13) NO METS

Answer 84

long standing pain (months to years) Lytic eccentric metaphyseal lesion. Sharply demarcated with a scalloped and sclerotic rim. Lesion ranges from 2-10cm. Low signal on T1. High signal on T2. Increased signal uptake will be seen.

Answer 85

Biphasic appearance.Low power will show. Hypercellular area with lobules of fibromyxoid tissue. Hypocellular area with chondroid material. Spindle-shaped cells or stellate-shaped cells. Mutlinucleated giant cells and fibrovascular tissue located between lobules. HIGHER POWER: Will show myxoid stroma with stellate cells.

Answer 86

Intralesional curretage and bone grafting. (Can also use PMMA) Recurrence- occurs in 25% of cases.

Answer 87

Low and high grade dedifferentiated chondrosarcoma Clear cell chondrosarcoma Mesenchymal chondrosarcoma

Answer 88

Osteochondroma (\<1% risk of malignant transformation) Multiple hereditary exostosis (1-10% risk of malignant transformation) Enchondroma (1% risk of malignant transformation) Ollier's disease (25-40% risk of malignatn transformation) Maffucci's (100% risk of malignant transformation)

Answer 89

Older patients 40-75 Slight male predominance Most common locations include: Pelvis, proximal femur, distal femur, and scapula. **Tumor location is importatn for diagnosis as the same histiology may be diagnosed as benign in the hand but malignant if located in the long bones.**

Answer 90

Histologic grade correlates with survival. See image attached. Axial, pelvis, and proximal extremity lesions have a more aggressive course. Advanced patient age Inadequate surgical margins Increaed telomerase activity as determined by reverse transcriptase-polymerase chain reaction. Show to directly correlate with recurrence.

Answer 91

Malignant immature cartilaginous tumor accouting for \<2% of all chondrosarcomas Most common in 3 and 4th decade of life Presents as an eiphyseal lesion (mistaken for low grade chondroblastoma) with insidious onset of pain. Locally destructive with potential to metastasize.

Answer 92

Chondrosarcoma variant which presents with a biphasic pattern of neoplastic cartilage with associated neoplastic small round blue cells. **Occurs in younger patients than typical chondrosarcomas.** **May occur at several ciscontinuous sites at presentation and can occur in the soft tissues.** treatment is neo-adjuvant chemotherapy followed by wide surgical resection

Answer 93

Needle biopsy is not indicated due to difficulties with diagnosis. Lesions are often heterogenous and difficult to diagnose on histology alone. Requires clinical, pathologic, and radiographic correlation.

Answer 94

lytic or blastic with reactive thickening of the cortex. 85% will have cortical changes. LOW GRADE- similar appearance to enchondroma with additional cortical thickening/expansion and endosteal erosion HIGH GRADE- Cortical destruction and a soft tissue mass. DE-DIFFERENTIATED- show a lower grade chondroid lesion with superimposed highly destructive area consistent with the high grade dedifferentiated chondrosarcoma

Answer 95

MRI to determine marros and soft tissue involvement. Bright on T1. CT- to determine cortical involvement in low grade lesions. Deep endosteal scalloping suggests chondrosarcoma instead of enchondroma. 90% have cortical breach. BONE SCAN- Very hot with chondrosarcoma so can be used to distinguish it from enchondroma.

Answer 96

Biphasic appearance with low grade chondrosarcoma adjacent to small round blue cells. ## Footnote **Mesenchymal chondrosarcoma**

Answer 97

Lobular architecture similar to toher cartilage neoplasms, but cells are large and vacuolated. Clear cell chondrosarcoma. Typically low to intermediate grade.

Answer 98

Bimorphic histology. Low grade chondroid component High grade spindle cell component ( similar histology to osteosarcoma, fibrosarcoma, MFH) 80% are chondrosarcomas with an extra destructive area

Answer 99

**Chondrosarcoma is generally resistant to radiation and chemotherapy.** Grade 1- intralseional currettage for extremities. Pelvis or axial skeleton most recommend wide excision. Grade 2 or 3- Wide surgical excision.

Answer 100

Grade 1- rare after wide resectionw ith negative margins. 5-15% after curettage with adjuvant treatment Grade 2- varies depdening on resection margins Grade 3- 25% local recurrence and \>30% rate of metastasis

Answer 101

**Primary lymphoma of bone (solitary site)**- Most primary lymphomas of bone are Non-Hodgkin's B-cell lymphomas rather than T-cell variants. Diagnosed when there is only a single node of disease for six months. **Very rare to have primary lymphom of bone.** ## Footnote **Multiple bony sites (no visceral sites)** **Bone and soft tissue lymphoma**

Answer 102

INCIDENCE: 10-35% of non-Hodgkin's lymphoma patients have extranodal disease DEMOGRAPHICS: Males\>females. Can occur in all age groups. Most common in patients aged 35-55. LOCATION: most common are pelvis, spine, and ribs. Bones with peristant red marros. Other common sites include knee, proximal femur, and shoulder girdle. RISK FACTORS: Immunodeficiency. Viral or bacterial infecions.

Answer 103

25% present with a pathologic fraacture. Pain unrelieved by rest. Can have neurologic symptoms from spinal compression. Fever, nightsweats, and weight loss (common B-cell symptoms) On physical exam can have warm and swollen large soft tissue masses.

Answer 104

Large ill-defined diffuse lytic lesions with a subtle mottled appearance More common in diaphysis of long bones "ivory vertebrae Multiple sites are common. Can show cortical thickening CT of chest, abdomen, and pelvis for staging. PET useful to stage and follow the disease.

Answer 105

Bone marrow aspiration and biopsy

Answer 106

Mixed small round blue cell infiltrate To differentiate from other small round blue cell tumors: **CD20, CD45, and lymphocyte common antigen positive** **CD99 negative and absent 11:22 chromosomal translocation** diffuse infiltration of trebeculae as opposed to nodular.

Answer 107

Multi-agent chemotherapy +/- local irradiation. Radiation is used to obtain locatl control in persistent disease. Chemotherapy alone is effective for most lesions. 70% 5-year survival in disseminated disease Fracture stabilization or prophylactic management.

Answer 108

immunoglobulins Heavy Chains: IgG (52%), IgA (21%), and IgM (12%) Light Chains: Kappa, lambda aka Bence Jones proteins

Answer 109

Multiple Myeloma Solitary Plasmacytoma Osteoclerotic myeloma **solitary plasmacytoma has the best prognosis**

Answer 110

Patients \> 40 years of age (median age is 60) Affects males \> females 2x more common in African Americans 5 year survival rate of 30% 10 year survival rate of 11% Median survival is 3 years Shortest survival is seen in pateints with renal failure.

Answer 111

Osteoclastic stimulation by malignant cells. Malignant cells bind bone marrow stromal cells to stimulate the production of receptor activator of nuclerar factor-k B ligand (RANKL) and other pro-osteoclastic mediators (macrophage colony-stimulating factor M-CSF, IL-6, IL-11, TNF) Osteoprotegerin synthesis is suppressed, resulting in further osteoclast activation. OPG competes with RANK to bind to RANKL as a decoy receptor.

Answer 112

hyper**C**alcemia: serum clacium \> .25 mmol/L (\>1mg/dL) higher than the upper limit of normal or \>2.75 mmol/L (\>11mg/dL) **R**enal insufficiency: creatinine clearance \<40 mL/min or serum creatinine \>177 umol/L (\>2mg/dL) **A**nemia: hemoglobin \>20g/L below the lowers limit of normal or hemoglobin \<100g/L **B**one lesions: \>=1 osteolytic lesion on radiographs, CT, or PET/CT

Answer 113

**Monoclonal plasma cells \>10% on bone marrow biopsy or biopsy-proven bony/extramedullary plasmacytoma and greater than or equal to 1 of the CRAB features and myeloma-defining events (MDEs). See the image for a list of those features and events.**

Answer 114

Plasma cell tumor occuring in a single skeletal location and lacking appropriate criteria for diagnosis of multiple myeloma (histologic biopsy confirming plasmacytoma and negative bone marrow biopsy with no plasma cells in the bone marrow). Sensitive to radiation Progresses to multiple myeloma in over 50% of patients **Obtain MRI and FDG-PET** additional lesions identified in 33% of patients

Answer 115

Multiple "punched-out" lytic lesions Only visible once \>50% destruction has occurred Lytic appearance Absence of sclerotic border because there is a lack of osteoblastic activity. Bone scans are cold in 30% so obtain a skeletal survery if suspicion for multiple myeloma.

Answer 116

anemia elevated creatinine hypercalcemia- present in 30% of patients due to excessive resorption of bone ESR often elevated SPEP (serum protein electrophoresis)- M spike present (50% IfG, 25% IgA) Beta-2 microglobulin- marker of prognosis/disease severity URINE: proteinuria. UPEP may show Bence Jones proteins (secreted immunoglobulin kappa and lambda light chains).

Answer 117

Round plasma cells with an **eccentric nucleus,** prominent nucleolus, and **clock face organization of chromatin**. Characteristic **clear area (Hoffa clear zone)** next to the nucleus represents the prominent Golgi apparatus involved in immunoglobulin (protein production)

Answer 118

annual surveillance

Answer 119

Multiagent chemotherapy +/- stem cell therapy +/- bisphosphonates For complete or impending fractures in patients with life expectancy \> 3 months -\> surgical stabilization and external beam radiation therapy. Kyphoplasty can be used in thos ewith vertebral fractures that are resistant to radiation.

Answer 120

Metaphyseal fibrous defect Nonosteogenic fibroma Cortical desmoid Fibrous cortical defect Fibromatosis Fibroxanthoma **All are names for a benign fibrogenic lesion that is related to dysfunctional ossification and is one of the most common benign bone tumors in childhood.**

Answer 121

occurs in 30-40% of skeletally immature children More common in males (2:1) and in children 5-15 years old. Located in the metaphysis of long bones. 80% are in the lower extremity. Distal femur \> proximal tibia \> distal tibia. Uncommon in proximal femur and proximal humerus. **usually spontaneously resolves. No malignant or metastatic potential.**

Answer 122

Congenital syndrome of multiple non-ossifying fibromas and: cafe au lait pigmentation mental retardation heart, eyes, gonads involved

Answer 123

Metaphyseal eccentric bubbly lytic lesion surrounded by a sclerotic rim Cortex may be expanded and thing. Length \> width Migrates to diaphysis and lesions enlarge (1-7cm) as the pateint grows. quantitative CT shown to be useful in predicting fracture risk.

Answer 124

Fibroblastic spindle cells in whirled or storiform pattern (helicopter in wheat field) hemosiderin pigmentation numerous lipophages and giant cells Fibroblastic connective tissue backround. Occasional ABC component.

Answer 125

Almost all are observation. Most lesion reossify as child enters 2nd and 3rd decade of life. Radiographs at 6 months, 12 months, and then annually until reossified. Pathologic fractures treated as you would normally treat the fracture. Symptomatic and large lesions with \> 50-75% cortical involvement can be treated with curettage and bone grafting. **Risk factors for pathologic fracture:** \>50% of transverse diameter of bone and \>33mm in length. 90% occur in lower extremity with 50% in distal tibia.

Answer 126

Undifferentiated pleomorphic sarcoma similar in presentation to osteosarcoma, but histologically different (lacks osteoid formation).

Answer 127

INCIDENCE: second most common bone sarcoma in adults after chondrosarcoma. DEMOGRAPHICS: Affects individuals 20 to 80 years of age. Highest rates of affected patients in 2nd to 4th decades. male \> female (3:2). More common in caucasians than African Americans or Asians. BODY LOCATION: 75% of cases from appendicular skeleton. Often metaphysis of long bones. Primarily distal femur, proximal tibia, and proximal humerus. RISK FACTORS: 25% arise as secondary lesion from bone infarct, Paget disease, or prior radiation.

Answer 128

50-60% survival at 5 years. worse prognosis with secondary MFH compared to primary lesions. pulmonary metastasis common in up to 30%. good response (\> 90% tumor necrosis ) to neoadjuvant chemotherapy found to have a much better prognosis. age younger than 40 years associated with improved disease-free survival rate.

Answer 129

New painful mass Often has constitutional symptoms as well. Fever, chills, night sweats, and weight loss.

Answer 130

lytic(can also be blastic) and destructive In metaphysis Cortical destruction with soft tissue extension MRI: Will show a deep seated heterogeneous mass that is low signal on T1 and high signal on T2. Often associated with internal hemorrhage.

Answer 131

Pleomorphic spindle cells and histiocytic cells in storiform pattern. Malignant multinucleated giant cells with grooved or indented nuclei. Hemorrhagic and necrotic regions not infrequent; suggest high-grade lesion.

Answer 132

neoadjunctive chemotherapy, wide resection, postoperative chemotherapy +/- radiation Trend towards limb salvage whenever possible. Radiation used whenever incomplete or questionable margins.

Answer 133

3:1 Male to female. Usually in patients \> 50 years Metastatic disese in 30-50%- occurs late in the course of the disease so long term follow up required. May spread to lung and rarely to other bony locations. 60% 5 year survival 25% long term survival Local extension may be fatal.

Answer 134

insidious onset of pain. Often complain of bowel or bladder changes. Sensory deficits rare due to distal nature of tumor. Constripation and occassional fecal incontinence. Motor deficits are rare because most lesions at S1 or distal. More than 50% of sacral chordomas are palpable on rectal exam.

Answer 135

Can be difficult to see on radiographs. CT will show bone destruction and soft tissue mass. MRI will be bright on T2

Answer 136

Gross: lobular and gelatinous. foamy, vacuolated, and physaliferous cell that grows in distinct nodules. HISTOCHEMICAL STAINING: keratin positive **important to distinguish from chondrosarcoma, which is not keratin positive.** **w**eakly S100 positive.

Answer 137

Radiation for inoperable tumors Wide margin surgical resection +/- radiation. Must be willing to sacrifice sacral nerve roots to obtain adequate surgical margins. Long term survival 25-50% en bloc corpectomy has best chance of local control with spinal lesions. **50% local recurrence is common** **Loss of bowel/bladder function postoperatively.** In order to preserve near normal function need to preserve bilateral S2 nerve roots or unilateral S2, S3, and S4 roots.

Answer 138

Most often occurs in the vertebral bodies and cranio-facial bones. Lytic lesion with vertical striations giving a "honey-comb" or "jail bar appearance" on radiographs May be multi-focal. Bone scan is warm to hot.

Answer 139

cavernous lesions with numerous thin walled blood vessels. Observation as long as they are asymptomatic. curettage and bone grafting it the lesion is symptomatic and accessible. Low dose radiation (25 to 40 Gy) if the lesion is symptomatic and inaccessible for above.

Answer 140

Non-neoplastic serous fluid-filled bone lesion thought to result from temporary failure of medullary bone formation near the physis. Usually in patients \<20 years of age Most often found in the proximal humerus of young patients. Can also be found in proximal femur, distal tibia, ilium, calcaneus, and occassionally metacarpals, phalanges, or distal radius. **Arises in the metaphysis adjacent to physis.**

Answer 141

Will often decrease in size and may heal after growth is compelete. **Fracture healing usually does not lead to cyst resolution.** Requires close follow up while in acitve phase due to recurrence and risk of fracture or growth arrest.

Answer 142

If cyst is adjacent to physis on radiographs then it is **active** If normal bone separates cyst from physis then it is **latent. see photo.**

Answer 143

central, lytic, well-demarcated metaphyseal lesion (2-3% cross physis) Cystic expansion with symmetric thinning of cortices "Fallen leaf" sign (pathologic fracture with fallen cortical fragment in base of empty cyst is pathognomonic) **ABC will be more expansive than UBC (UBC is usally not wider than physis).**

Answer 144

Cyst with thin fibrous lining containing fibrous tissue, giant cells, and hemosiderin pigment. Chronic inflammatory cells may be found in small numbers Cementum spherules (calcified eosinophilic fibrinous material) in 10% Uniform opulation of spindle cells without nuclear atypia

Answer 145

avoid operative treatment in active lesions as communication with physis may lead to growth arrest.

Answer 146

75% of patients are \< 20 yrs. 25% in spine 20% in long bones, usually in metaphysis. Metatarsal is the most common location in the foot. Can be seen in posterior elements of the pelvis.

Answer 147

Associated with other tumors 30% of the time: Giant cell tumor Chondroblastoma Fibrous dysplasia Chondromyxoid fibroma NOF

Answer 148

RADIOGRAPHS: expansile, eccentric and lyic lesion with bony septae (bubbly appearance). Usually in metaphysis. Often have thin rim of periosteal new bone surrounding lesion. MRI or CT will show multiple fluid lines. Can expand into soft tissue

Answer 149

cavernous space blood filled spaces without an endothelial lining. Cavity lining can have: numerous benign giant cells Spindle cells Thin strands of woven new bone present.

Answer 150

**ABC with acute fracture:** Non-operative fracture management until fracture has healed. Once healed treat as you would normally treat an ABC **Symptomatic ABC no fracture:** aggressive curettage (+/- adjuvant) and bone grafting. Adjuvants include phenol, argon beam, and liquid nitrogen. Local recurrence in up to 25% and more common in children with open physes.

Answer 151

developmental abnormality caused by failure of the production of normal lamellar bone. Areas of skeleton remain poorly mineralized trabeculae. **GNAS mutation** GS alpha protein (chromosome 20q13) activating mutation affects cAMP signaling pathway leading to increased production of cAMP.

Answer 152

Females \> males Found in any and all ages. Onset for 75% of patients at \<30 years of age Any bone can be involved. Proximal femur is most common follwed by rib, maxilla, and tibia

Answer 153

**Mcune Albright syndrome-** Defined by presence of cafe au lait spots in coast of Maine pattern. Endocrine abnormalities -\> precocious puberty. Renal phosphate wasting due to FGF-23 (oncogenic osteomalacia). Unilateral polyostotic fibrous dysplasia obtain AP spine radiographs to look for scoliosis. **Mazabraud syndrome-** polyostotic fibrous dysplasia. Soft-tissue intrmuscular myxomas. **Osteofibrous dysplasia-** rare form that primarily affects the tibia and is confined to the cortices. **nonorthopedic manifestations can include severe cranial deformities with blindness.**

Answer 154

1% risk of malignant transformation to osteosarcoma, fibrosarcoma, or malignant fibrous histiocytoma.

Answer 155

Cafe au lait spot with large irregular border. Neurofibromatosis will be smaller and have more defined borders.

Answer 156

Central lytic lesion in medullary canal. **Ground glass appearance** "punched out" lesion with well defined margin of sclerotic bone is common. May have cortical thinning with expansile lesion. **Shepherd's crook deformity.** **Spine radiograph will show vertebral collapse and kyphoscoliosis.**

Answer 157

**alphabet soup** or **chinese letters.** Fibroblast proliferation surrounding islants of woven bone. The woven bone lacks osteoblastic rimmin (osteofibrous dysplasia has osteoblastic rimming)

Answer 158

ASYMPTOMATIC- observation SYMPTOMATIC POLYOSTOTIC- Bisphosphonate therapy. Effective in decreasing pain and recucing bone turnover. SYMPTOMATIC, IMPENDING/ACTUAL FRACTUES, SEVERE DEFORMITY- internal fixation and bone grafting. Need to use allograft. Intramedullary device is more effective than a plate for coxa var deformities that require an osteotomy.

Answer 159

Rare form of fibrous dysplasia that primarily affects the tibia and is confined to the cortices. **Also knonw as ossifying fibroma and Campanacci lesion.** Males \> females. Usually found in younger children (\< 10 years old) Does NOT have GS alpha activating mutation like fibrous dysplasia. **lesions usually regress and do not cause problems in adulthood.**

Answer 160

Painless swelling. anterior or anterolateral bowing of the tibia. Pseudoarthrosis develops in 10-30% of patients. In these cases they have local tenderness and pain.

Answer 161

anterior eccentric lytic tibial lesion in a child that often leads to tibial bowing. Confined to anterior cortex, diaphyseal, with no periosteal reaction. Need to differentiate from adamantinoma.

Answer 162

Histology similar to dibrous dysplasia EXCEPT **osteoblastic rimmin is present** fibroblast proliferation surrounding islands of woven bone with osteoblastic rimmin May have giant cells mitotic figures are common.

Answer 163

Observation is first line of treatment for most patients. Bracing if deformity is significant and interferes with walking. Deformity correction with osteotomy in rare cases. **perform after skeletal maturity**

Answer 164

Thought to be due to a slow virus infection (intra-nuclear nucleocapsid-like structure) such as paramyxovirus or RSV. Increased osteoclastic bone resorption is the primary cellular abnormality.

Answer 165

Peak incidence in the th decade of life. Common in caucasians (northern european/anglo-Saxon descent Males = Females May be monostotic or polyostotic. Common sites include femur \> pelvis \> tibia \> skull \> spine Most cases are spontaneous but familial clusters with 40% autosomal dominant transmission has been reproted.

Answer 166

High output heart failure.

Answer 167

Less than 1% develop malignant Paget's sarcoma Osteosarcoma \> fibrosarcoma and chondrosarcoma Most common in pelvis, femur, and humerus. **Poor prognosis 5-year survival for metastatic Paget's Sarcoma \< 10%** Treatment includes chemotherapy and wide surgical resection.

Answer 168

LYTIC PHASE- intense osteoclastic resorption MIXED PHASE- resorption and compensatory bone formation SCLEROTIC PHASE- ostoeblastic bone formation predominates **All three phases may co-exist in the same bone**

Answer 169

frequently asymptomatic and found incidently Pain may be presenting symptom due to stress fractures and increased vascularity and warmth. **New intense pain and swelling is suspicious for Paget's Sarcoma.** Can present with high-output cardiac failure particularly if large/multiple lesions & pre-existing diminished cardiac function.

Answer 170

Coarsened trabeculae which five the bone a blastic appearance. Because of the three different phases can have both increased and decreased density. lytic phase- "blade of grass" or "flame shaped" lucent advancing edge. Remodeled cortices. Long bone bowing **osteitis circumscripta (cotton wool exudates in skull)** Bone scan accurately marks site of disease very hot in lytic and mixed phase, less hot in sclerotic phase.

Answer 171

elevated serum ALP elevated urinary collagen cross-links elevated urinary hydroxyproline (collagen breakdown marker) Increased urinary N-telopeptide, alpha-C-telopeptide, and deoxypyridinoline Normal calcium levels.

Answer 172

woven bone and irregular broad trabeculae with disorganized cement lines in a mosaic pattern. Profound bone resorption- numerous large osteoclasts with multiple nuclei per cell virus-like inclusion bodies in osteoclasts Paget's osteoclasts larger, more nuclei than typical osteoclasts.

Answer 173

**Eosinophilic granuloma-** usually a single self-limited lesion found in younger patients. **Most commonly occurs in children \< 20 years 80% of the time.** **Hand-Schuller-Christian Disease-** Chornic disseminated form with bone and visceral lesions. Also known as langerhans cell histiocytosis with visceral involvement. **Children \> 3 yrears of age** Prognosis depends on response to chemotherapy. Generally worse prognosis with extraskeletal involvement. **Letterer Siwe disease-** Fatal form that occurs in yound children. **children \< 3 years of age**

Answer 174

Commonly presents in the skull, ribs, clavicle, scapula, and mandible. Isolated lesions of the spine (thoracic most common) Can also occur in diaphyseal regions of long bones and the pelvis. **Hand-Schuller-Christian disease-** Multiple bony sites, multiple lytic skull lesions. **visceral involvement of the lungs, spleen, liver, skin, and lymph nodes.**

Answer 175

Multiple lytic skull lesions Diabetes insipidus Exopthalmos Patients will also present with diffuse or nonspecific abdominal or chest pain.

Answer 176

Known as "the great mimicker" as it appears similar to many lesions DIAPHYSEAL LESIONS: well defined intramedullary lytic or "punched-out" lesion. Cortex may be thinned, expanded, or destroyed. May have periosteal reaction. METAPHYSEAL LESIONS: Extend up to but not through physis. Less central location than diaphyseal lesions. SPINAL LESIONS: vertebra plana (flattened vertebrae) in spine. Increased kyphosis.

Answer 177

**Langerhan's cells:** mononuclear histiocyte-like cells with oval nuclei with well-defined round or oval cytoplasm. A prominent nuclear groove (coffee bean nuclei) can be seen in most of the nuclei Eosinophilic cytoplasm (pink generally) Stain with CD1A. Shows up as a brown pigmentation similar to hemosiderin. **Giant cells are present.** **Lack of nuclear atypia and atypical mitoses-** differentiates this condition from malignant conditions such as Ewings Sarcoma, lymphoma of bone, and metastatic neuroblastoma, which may look similar based on the round cells alone.

Answer 178

electronmicroscopy shows **birbeck granules** seen inside Langerhan's cells. Found in patients with eosinophilic granuloma.

Answer 179

For most observation as this is a self limited process. Bracing for spine kyphosis which will correct in 90%. The other 10% will have spinal deformity correction. Low dose irradiation (600-800cGy) for lesions in the spine that are causing issues but not amenable to injectio or open treatment. **Chemotherapy** for diffuse HSC. Corticosteroid injections for isolated lesions. **curretage and bone grafting** for lesions that endanger the articular surface or are at risk for impending fractures.

Answer 180

A reactive process that is characterized by a well circumscribed proliferation of fibroblasts, cartilage, and bone within muscle. Form of HO that is the result of direct trauma or intramuscular hematoma. **Must differentiate from tumors**

Answer 181

Rare subtype of heterotopic ossification Involves mutation of the ACVR1 gene (activin A type I receptor gene, a BMP type-1 receptor) Has numerous areas of extraskeletal ossification. Hallmark is rigid deformed spine.

Answer 182

Most common in young active males 15-35 years of age. Most common locations are quadriceps, brachialis, and gluteal muscles. Usually self limiting. Mass begins to decrease in size after 1 year.

Answer 183

Peripheral bone formation with central lucent area. May appea as "dotted veil" pattern. MRI with gadolinium will who rim enhancement within the first 3 weeks. CT scan lesion has an eggshell appearance.

Answer 184

PERIPHERY OF LESION- mature trabeculae of lamellar and woven bone. Calcification seen on xray CENTER OF THE LESION- irregular mass of immature fibroblasts. cartilage component may be present. No cellular atypia.

Answer 185

Rest, ROM (avoid passive stretching, needs to be active motion with PT), and activity modification. Radiographic monitoring to confirm maturation of the lesion Surgical excision only if it remains a problem after maturation. **Do not operate in the acute phase. Excision of the lesion within 6 to 12 months predisposes to local recurrence.**

Answer 186

Rare benign painful disorder of the extremities characterized by formation of periosteal new bone? Usually presents before age 40. No gender preference. More common in the lower extremities but can appear in any bones. Patients will present with pain, reduced ROM, and joint contractures. Physical exam will show **fibrosis of skin with significant induration and erythema.** Painful hyperostoses

Answer 187

Cortical hyperostosis. This may flow across joints. **dripping candle wax appearance** with dense hyperostosis that flows along the cortex of the bone. HISTOLOGY: normal haversian systems with enlarged bone trabeculae and without cellular atypia or mitotic figures.

Answer 188

MILD SYMPTOMS WITH ADEQUATE MOTION: observation **bisphosphonates show to help with pain and swelling.** SEVERE CONTRACTURES WITH LIMITED MOBILITY AND PAIN: resection of the hyperostotic bone with contracture release.

Answer 189

PRIMARY MALIGNANT GIANT CELL TUMOR: Metastatic to lung in 2-4% of cases **wrist and hand lesions have a greater chance of metastasis** SECONDARY MALIGNANT GIANT CELL TUMOR: occurs following radiation or multiple resections of giant cell tumor **c-myc oncogene** or **p53** metastatic GCT has a 5 year 76% disease-free survival rate and a 17% mortality rate.

Answer 190

More common in females (**unlike most bone tumors which show male predominance)** Ages 30-50 years Distal femur \> proximal tibia \> distal radius \> sacral ala 50% occur around knee 10% in sacrum and vertebrae (vertebral body) with the sacral ala most common site in axial skeleton Phalanges of the hand is also a very common location

Answer 191

Radiographs including chest x-ray. Eccentric lytic epiphyseal/metaphyseal lesion that borders subchondral bone. Chest CT ot look for pulmonary mets. MRI. Will be dark on T1 and very bright on T2 with clear demarcation.

Answer 192

Tumor cell activation of osteoclasts. Likely accomplished through the RANK pathway and requires tumor cells to secrete or stimulate osteoblast to produce RANKL. The multinuclear giant cells and the osteocytic stromal cells of giant cell tumor are locally aggressive, but they do not have the capcity to dissolve bone.

Answer 193

RADIATION THERAPY: only indicated for inoperable (sacral or vertebral body) or multiply recurrent lesions MEDICAL MANAGEMENT: denosumab or bisphosphanates. Excellent response has been seen with denosumab (85-90% destruction of giant cells) Post-surgical treatment with bisphosphonate has shown to lower recurrence rates by 25-30%

Answer 194

**Extensive curettage, adjuvant treatment, and reconstruction.** Majority of lower extremity lesions, hand lesions are most controversial. **Outcomes** 20-40% recurrence with curettage alone versus 3-10% with adjuvatn treatment. **Complete resection and reconstruction.** When currettage is not possible due to structural compromise. Extensive involvement of vertebral body -\> total en bloc spondylectomy. **Amputation.** Hand lesions with cortical breathrough which are not amendable to intercalary resection. **has the lowers incidence of recurrence.**

Answer 195

nasopharyngitis and arthralgias contrainidcation is severe hypocalcemia.

Answer 196

Phenol, liquid nitrogen, hydrogen peroxide, argon beam, and high-speed burr. High-speed burr without any other adjuvant has recurrence rate of 12% Liquid nitrogen has been associated with an increased incidence of pathologic fracture and vascular injury.

Answer 197

Yes but it is very rare \<1% of the time. 9 years from previous radiation treatment 19 years from spontaneous transformation

Answer 198

between 10-14% Differentiate from primary ABC because of enhancing soft-tissue component in GCT (not present in primary ABC)

Answer 199

within 2 months of neurologic injury. Hip is most common for both brain and spine injury. Occurs on affected (spastic) side. elbow HO is more common following brain trauma.

Answer 200

True Especially in men with hypertrophic osteoarthritis and women \> 65 yrs

Answer 201

ORTHOPAEDIC MANIFESTATIONS: Pathologic fractures, nerve impingement, soft tissue contractures, CRPS, and joint ankylosis Nonorthopaedic conditions- skin maceration and hygiene problems.

Answer 202

The appearance of bony cortex suggests mature HO Sharp demarcation from surrounding tissue trabecular pattern. **radiographs are not useful for early diagnosis as calcium is not deposited until 7-10 dyas later than symptom onset.**

Answer 203

Triphasic bone scan is the most commonly used diagnostic study. Ultrasound can also be used.

Answer 204

**Elevated serum alkaline phosphatase**. ALP removes inhibitors of mineralization. Elevated 12 wks after surgery is a predictor. **Elevated CRP**. correlates with inflammatory activity of HO better than ESR. normalization of CRP may correlate with maturity of HO. **Elevated ESR.** 12wks after THA is predictor **Elevated CK-** correlates with extent of muscle involvement.

Answer 205

bisphosphonates & NSIADs despite not much literature to support its use. **Indomethacin is most commonly used. 75mg/day for 10 days to 6 weeks.** Perioperative radiation. Also commonly used despite not much literature supports. A single perioperative dose of 700 cGy can be given either 4 hours preop or within 72 hours postoperatively.

Answer 206

Indicated if there is severe loss of motion and decreased function. TIMING OF RESECTION (CONTROVERSIAL): Should be a marked decrease in bone scan activity AND normalization of ALP. 6 months following general trauma 1 year following SCI 1.5 years following TBI (most controversial of the three). Postop give indomethacin, irradiate, and perform gentle ROM.

Answer 207

INFECTION- higher rate of infection folloiwng joint arthroplasty if HO is present. FRACTURES- of osteoporotic bone- can be intraop or during PT RECURRENCE- recurrence rates correlate with neurolgoical injury AVN- if extensive dissection or stripping is required.

Answer 208

Rare and poorly understood hereditary metabolic **dysfunction of phosphate regulation** associated with **massive periarticular calcinosis in the extracapsular soft tissues**. More common in females and African-Americans Hip (trochanteric bursa is most common location then shoulder **onset in childhood or early adolescence**

Answer 209

FGF-23 inborn abnormality of phosphorus metabolism

Answer 210

**Radiographs-** amorphos, cystic, lobular (circular or oval) well-demarcated calcification in periarticular location. **direct involvement of the bones or joints is rare.** **CT-** may demonstrate fluid-fluid levels within some of these masses. calcium layering ("sedimentations sign") **MRI-** Also may show fluid-fluid levels with alternating areas of high signal intensity and signal void.

Answer 211

normal or slightly elevated renal, parathyroid function normal or slightly elevated serum calcium, phosphorus, uric acid, and alkaline phosphatase. HISTOLOGY: lobulated soft tissue masses with well defined capsules and thick septae. Masses are filled with calcareous material(calcium phophate, calcium carbonate, and calcium hydroxyapatite) and fluid

Answer 212

Obersvation treatment of choice for non-symptomatic lesions. If **symptomatic** compete surgical excision to decrease rate of local recurrence. Risk of recurrence is greater if lesion is poorly circumscribed or if excision is performed while lesion is actively growing.

Answer 213

PCR can identify the fusion protein EWS-FLI1 that is formed by the 11:22 translocation.

Answer 214

typically found in patients from 5-25 years of age Second most common malignant bone tumor in children. Uncommon in African Americans and Chinese 50% are found in the diaphysis of long bones- Most common locations pelvis, distal femur, proximal tibia, femoral diaphysis, and proximal humerus.

Answer 215

5 yr- 65-80% for localized disease and 25-40% for metastatic disease 10 yr survival- 60% for localize disease and 30% for metastatic disease See image for complete list. **Metastases most important prognostic indicator.** Lung mets better prognosis than bone/marrow mets. Skip mets better prognosis than distant.

Answer 216

Bone scan- will show very hot lesion(s) MRI- required to identify soft-tissue extension and marro involvement. Often shows a large soft tissue component. CT chest- required to look for pulmonary metastasis Bone Marrow biopsy- required as part of workup to rule out metastasis to the marrow

Answer 217

Large destructive lesion in the diaphysis or metaphysis with a permeative moth-eaten appearance Lesion may be purely lytic or have variable amounts of reactive new bone formation Periosteal reaction may five "onion skin" or "sunburst" appearance

Answer 218

**Often mimics an infection** ESR and WBC is elevated Anemia is common Elevated lactic dehydrogenase- **high levels \>200 is a poor prognostic indicator.**

Answer 219

Gross appearance may have liquid appearance mimicking pus CHARACTERISTIC: sheets of monotonous small round blue cells. Prominent nuclei and minimal cytoplast. May have pseudo-rosettes (circle of cells with necrosis in center) IMMUNOSTAINING: Postive- **CD99 (in 95%),** MIC2, vimentin, PAS positive (intracellular glycogen), neuron specific enolase (NSE) S100, and Leu7. Negative- cytokeratin, **reticulin (positive in lymphoma), neurofilament (positive in neuroblastoma)**

Answer 220

\< 5 yrs: neuroblastoma or leukemia 5-10 yrs: eosinophilic granuloma 5-30 yrs: Ewing's sarcoma \> 30 yrs: lymphoma \> 50 yrs myeloma

Answer 221

**Chemotherapy and radiation-** for non-resectable tumors or where functional deficit is unacceptable. **However trend is increasingly towars surgical resection because of morbidity and risk of secondary malignancies associated with Ewing Sarcoma.** OPERATIVE: Chemotherapy with limb salvage resection +/- adjuvant radiation is the stnadard of care. Chemo for 8-12 weeks pre-op and then 6-12 months after resection. **Radiation if there are positive margins, widely metastatic disease, or where chemotherapy response if poor.**

Answer 222

**Secondary neoplasm-** 10-20% risk of bone sarcoma at 20 yrs with radiation. Dose dependent. \> 60Gy confers 20% risk while \< 48Gy has no risk. acute myeloid leukemia/myelodysplasia from chemotherapy in 2% of survivors. Arises around 5 years after diagnosis. **Recurrence-** extremely poor prognosis \<10% survival at 5 yrs after recurrence. **METS-** 25-30% have macromets on presentation. CURE RATES WITH CHEMO: 10% have bone mets at presentation. Cure rates with chemo 30% for lung mets alon. 20% for bone mets. 15% for combined lung and bone.

Answer 223

Less than 300 cases have been documented Occurs in young adults 20-40 years of age May metastasize to the lungs in 25% therefore long term follow-up is recommended. Recurrence is uncommon with negative margin excision. Historically it was thought that osteofibrous dysplasia was a precurssor but current studies doubt this.

Answer 224

Multiple sharply circumscribed lucent lesions ("soap bubble" appearance) with interspersed sclerotic bone in mid tibia **Some lesions may destroy cortex, this is greatest differentiator on imaging from osteofibrous dysplasia.** May see bowing of the tibia. No periosteal reaction unlike other primary bone tumors.

Answer 225

Biphasic- contains both epithelial and ribrous mesenchymal cells. Nests of epithelial-like cells arranged in palisading or glandular pattern. Stains for keratin. Notice the epithelial islands in the image. Background of fibrous stroma.

Answer 226

Wide margin surgical resection. Low grade so radiotherapy or chemotherapy is not typically used. Often requires placement of an intercallary graft or megaprosthesis.

Answer 227

BLT Kosher Pickle Breast Lung Thyroid Kidney Prostate Bone is the third most common site for metastatic disease behind Lung and Liver.

Answer 228

Most common site is the thoracic spine 2nd most common site is proximal femur. Proximal femur is the most common location for pathologic fracture with 50% in the femoral neck. **65% nonunion rate.**

Answer 229

osteoblastic bone metastases like those caused by prostate cancer or certain types of breast cancer.

Answer 230

Metastatic hypercalcemia other major symptom is polyuria and plydipsia. Hydration, loop diuretics, and bisphosphonates.

Answer 231

Thyroid: 48 months Prostate: 40 months Breast: 24 months Kidney: variable but can be as short as 6 months Lung: 6 months

Answer 232

**Batson's vertebral plexus-** valveless venous plexus of the spine that provides a route of metastasis from organs to axial structure including vertebral bodies, pelvis, skull, and proximal limb girdles. **Arterial tree metastasis-** mechanism by which lung and renal cancer spread to the distal extremities.

Answer 233

oncogenic cell releases cytokines IL-6, IL-11, PTHrP, and TGF-beta. PTHrP and TGF-beta activate osteoblasts Osteoblasts secrete RANKL, that binds to RANK on osteoclasts and activates osteoclasts.

Answer 234

prostate cancer cells secrete endothelin 1 (ET-1) ET-1 binds to endothelin A receptor (ETAR) on osteoblasts and stimulates osteoblasts ET-1 decreases WNT suppressor DKK-1 -\> activates WNT pathway, increasing osteoblast activity.

Answer 235

Radiographs CT chest/abdomen/pelvis technetium bone scan to detect extent of disease- myeloma and thyroid carcinoma are oftne cold on bone scan. evaluate with a skeletal survery. LABS: CBC, ESR, BMP, LFTs, Ca, Phos, Alkaline phosphatase, SPEP, and UPEP. **in patients where a primary carcinoma is not identified, obtaining a biopsy is necessary to rule out a primary bone lesion.** metastatic adenocarcinoma not identified by CT of the chest, abdomen, and pelvis is most likely from a small lung primary tumor.

Answer 236

Lung cancer Lung is also the most common cause of acral mets and lesions distal to elbow and knee.

Answer 237

Epitherlial cells in clumps or glands in a fibrous stroma. Keratin- positive in epithelial cells, so all metastatic carcinoma CK7- breast and lung cancer TTF1- lung cancer

Answer 238

bisphosphonate therapy- IV pamidronate most commonly used. Stabilization of complete fracture with postoperative radiation. **All patients require postop radiation unless imminent death or area has been previously irradiated. Area should inclued the entire fixation device.** start after surgery. See table of treatment based on cancer type.

Answer 239

Thyroid carcinoma prior to operative intervention.

Answer 240

Cemented hemiarthroplasty. Only perfrom THA if there is acetabular involvement. Cephalomedullary nail with currettage and cement. **As long as it doesn't involve the femoral head can consider nail for both complete and impending fractures.** hemiarthroplasty vs THA. Take into account age of patient. Any existing arthritic disease. Life expectancy. Morbidity of the surgery and stability of the patient.

Answer 241

Angiosarcoma

Answer 242

Males \> Females 85% occur in patients \> 15 years old 60% occur in extremities

Answer 243

Synovial sarcoma (SYT-SSX fusion) Rhabdomyosarcoma (alveolar) Myxoid liposarcoma

Answer 244

Lung 5% (most commonly epitheliod, synovial, angiosarcoma, rhabdomyosarcoma, clear cell)

Answer 245

tumor stage Unplanned excision- referral to orthopaedic oncologist for multidisciplinary workup and repeat excision is critical.

Answer 246

True, even though there are over 50 subtypes recognized the generally present the same. Histologic findings and molecular signatures are used to distinguish the individual types.

Answer 247

isointense with msucle on T1 T2 will have high signal intensity. IV gadolinium: peripheral enhancing zone and non-enhancing necrotic center. **MRI can be diagnostic for lipomas, neurilemoma (schwannoma), and intramuscular myxoma.** If MRI is diagnostic can be removed withouth a biopsy.

Answer 248

Wide surgical resection & radiation therapy. eliptical incision is used to incorporate biopsy and drain sites. 50 Gy pre-operative and 66 Gy postoperative radiation is standard dose. Chemotherapy is controversial for soft tissue sarcomas. **Is used regularly for rhabdomyosarcoma and Ewings Sarcoma.** Surgical resection of lung mets is standard of care if the preop evaluation shows that complete resection is possible. **curative in up o 25% of patients.**

Answer 249

**Radiation induced:** pre-operative radiotherapy associated with a \> 30% risk for wound complications. However, post-operative radiation is associated with greater radiation induced morbidity and risk of radiation-induced sarcoma. EARLY effects: desquamation, delayed wound healing, and infection LATE effects: fibrosis, post-radiation fracture, possibly secondary sarcoms **Recurrence:** local recurrence \<10% with radiation and surgery. The most common location for recurrene of a low-grade STS is locally.

Answer 250

Benign encapsulated tumor composed of Schwann cells on the surface of a peripheral nerve. also known as a schwannoma peak incidence is in the 3rd to 6th decades of life. Often occurs on flexor surfaces of extremities, head, and neck. Large lesions may occur in pelvis. **Associated with mutation affecting NF2 gene.** **Malignant transformation is extremely rare.**

Answer 251

dark T1 Bright T2 diffuse enhancement with gadolinium **May show string sign** difficult to differentiate from neurofibroma.

Answer 252

**Verocay bodies is pathognomonic** composed of two rows of aligned nuclei in a palisading formation. depicted below. Will also have **Antoni A** (a pattern of spindle cells arranged in intersecting bundles also referred to as a **spindle cell battle formation.** depicted on the image on the reverse of the car. There is also **Antoni B** which are areas with less cellularity with loosely arranged cells. **strongly uniform S100 antibody staining.**

Answer 253

observation for asymptomatic lesions. Marginal excision if symptoms are interfering with quality of life. **Nerve function may be preserved with careful dissection, excising the lesion parallel to the nerve fascicles so the lesion may be extruded.** Small risk of sensory deficits. Recurrence is rare.

Answer 254

proliferative disease of the synovium that results in multiple intra-articular loose bodies. usually younger adults 30-50 years of age. 2:1 Male to Female. Knee is most common location Slow progression of pain, swelling, and decreased ROM.

Answer 255

may or may not show on radiographs depending on stage of disease. May show stippled calcifications. Initially cartilage nodules are only visible on MRI with a lobular appearance. In later stages signal drops off due to clacification. HISTOLOGY: shows discrete hylaine cartilage nodules in various stages of calcification. Chondrocytes with mild atypia, binucleate cells, and occassional mitoses.

Answer 256

observation if symptoms are mild. Open or arthroscopic synovectomy and loose body resection is symptoms are severe and affecting ROM. May prevent degenerative joint changes.

Answer 257

False. cellular origin is unkown but it is not a synovial cell. Arises near joints, but is rarely within joints.

Answer 258

May develop in 30-60% of patients. Lung is the most common location. Rare soft tissue sarcoma that can metastasize to lymph nodes ( others include epitheliod sarcoma, angiosarcoma, rhabdomyosarcoma, and clear cell sarcoma) Lung mets still worse prognosis than lymph mets. Overall prognosis is poor. 5 year survival is 50% 10 year survival is approximately 25% SYT-SSX2 fusion type better prognosis.

Answer 259

may see mineralization in tumor on radiograph that resembles HO. CT can show calcifications. MRI reveals a heterogenous mass that is typically dark on T1 and bright on T2.

Answer 260

Classically will hsow biphasic appearnace with spindle cells and epithelial cells. STAINS POSITIVE FOR: Vimentin, epithelial membrane antigen, sporadic S-100, and epithelial cells will stain positive for keratin.

Answer 261

Wide surgical resection with adjuvatn radiotherapy.

Answer 262

Rhabdomyosarcoma and Ewing sarcoma

Answer 263

idiopathic monoarticular neoplastic synovial disease. Characterized by exuberant proliferation of synovial villi and nodules Now thought to be neoplastic. 5q33 chromosomal rearrangement. Increased expression of CSF1 gene. Ages 30-40 but can occur at any age. Equal male to female.

Answer 264

**Localized (intra-articular or classic form)**. Knee is the most common site of involvement (80%) Knee \> hip \> ankle \> shoulder \> elbow **Diffuse (extra-articular extension)** **Giant cell tumor of tendon sheath-** occurin galong tendon sheaths of hands and feet. 50% of patients will have prior history of trauma to the area.

Answer 265

RADIOGRAPHS: cystic erosion with sclerotic margins on both sides of joint. MRI: Low signal intensity on both T1 and T2 due to hemosiderin deposits "blooming artifact" signal loss on gradient-echo sequencs because of the hemosiderin deposits. Allows evaluation of both intra-articular and extra-articular disease.

Answer 266

Gross appearnce will be brownish or reddish inflamed synovium HISTOLOGY: mononuclear stromal cells infriltrating the synovium **hemosiderin stained multinucleated giant cells** highly vascular milli with hyperplastic synovial cells. pigmented foam cells (lipid-laden histiocytes)

Answer 267

no role for obervation if disease is even minimally symptomatic. Total synovectomy (classified as marginal excision) Recurrence is common. External beam irradiation when combined with a total synovectomy can reduce rate of recurrence to 10-20% **draw back of arthroscopic treatment is difficult to access posterior portions of joint and cannot address extraarticular disease.** **For diffuse PVNS can do arthroscopic anterior and open posterior synovectomy.**

Answer 268

Recurrence- 30% despite compete synovectomy. Same rates for arthroscopic vs open. Reduced by external beam radiation.

Answer 269

Also knonw as neurofibrosarcoma or malignant schwannoma. Arises from a peripheral nerve or neurofibroma 30-55 yrs for solitary neurofibromas 20-40 years for neurofibromatosis type 1 Most cases associated with NF-1 mutation 5 year survival solitary lesion 75% 5 year survival associated with NF-1 is 30%

Answer 270

MRI: T1- low intensity. T2-high intensity spindle cells with vavy nuclei resembling fibrosarcoma. Postivie S100 and keratin staining.

Answer 271

Wide surgical excision with radiation. In general treated as high-grade sarcoma. Wide resection should inlcude entire affected nerve. Preop radiation.

Answer 272

Schwannoma involves schwann cells alon. Neurofibroma is also a benign nerve sheat tumor but it has **multiple cell types.** nonmyelinating Schwann cells, fibroblasts (predominant cell type), and perineural cells.

Answer 273

Arise in nonmyelinating Schwann cells with biallelic inactivation of NF1 tumor-suppressor gene. Loss of expression of protein neurofibromin: neurofibromin negatively regulates RAS-mediated pathway -\> loss of neurofibromin leads to increased RAS activity. -\> affects RAS-dependent MAPK activity which is essential for osteoclast function and survival. Rapid hyperplasia of nonmyelinating Schwann cells into neurofibromas after NF1 inactivation -\> recruits perineural cells, fibroblasts, mast cells, and endothelial cells.

Answer 274

See image for physical exam and NIH criteria. Associated with NF1: dystrophic kyphoscoliosis rib penciling intraspinal neurogibromas and dumbbell lesions Dural ectasia Meningiomas.

Answer 275

Solitary neurofibromas are found central to the nerve fibers Schwannoma are found eccentric to the nerve fibers **nerve continuity sign-** fusiform tumor in continuity with the neurovascular bundle **split fat sign-** fusiform tumor surrounded by a thin margin of fat because the mass within the neurovascular bundle enlarges and displaces the adjacent intramuscular fat **target sign-** lesion of high signal intensity peripherally and low signal centrally (on coronal STIR)

Answer 276

overall hypocellular with predominantly fibroblasts with some Schwann cells, mast cells, and lymphocytes. Elongated wavy nuclei Stroma is a rich wire-like collagen fiber netwrok. Distorted structures resembling Pacini or Meissner corpuscles. Variable S100 staining.

Answer 277

observe for most if very symptomatic then can consider surgical excision. May require nerve grafting.

Answer 278

Very rare. Fewer than 100 case reports of extra-fascial leiomyosarcoma of bone. thought to arise from the smooth muscle cells linging small blood vessels. Occurs in soft tissue (ex. uterus) or bone. When in bone most commonly in metaphysis of long bones with most frequent locations femur, tibia, ilium, and humerus. 25% recurrence rate. 25% mets rate. 75% survival at 3 years with treatment.

Answer 279

RADIOGRAPHS: purely osteolytic lesions with ill-distinct margins, moth-eaten, or permeative pattern of bone destruction. Primarily extramedullary but can extend into soft tissues. Chest radiograph and CT of chest in all patients to look for mets. MRI: dark on T1 (similar to muscle tissue). Heterogeneous on T2 with areas of increased signal intensity. Contrast causes diffuse enhancement of signal within the lesion.

Answer 280

spindle cell neoplasm cigar-shaped nuclei cells arranged into fascicles along with myofibrils running parallel presence of actin and vimentin immunoreactivity. See image on other side of card.

Answer 281

**chemotherapy-** diffuse metastatic disease to the lungs. Large pelvic masses with neurovascular involvement that preculde safe resection. Variable response. Better with combined chemo and surgery than surgery alone. **radiation-** controversial, may be used for contaminated resection bed. **operative-** early wide resection of primary lesion and secondary reconstruction is the standard of care. +/- chemo and radiation

Answer 282

Rhabdomyosarcoma- A malignatn tumor of the primitive mesenchyme. FOUR SUB-TYPES: **Embryonal**- occurs in infants and young children **Alveolar**- occurs in adolescents and young adults **Botryoid**- occurs in infants and young children, typically in the vagina (aka Sarcoma botryoides or "bunch of grapes" **Pleomorphic-** tends to occur in older patients 40-70 yrs.

Answer 283

t(2;13) translocation. forms Pax3-FKHR fusion protein **nodal metastasis** are known to occur with rhabdomyosarcoma. consider sentinel lymph node biopsy as part of treatment. **bone marrow biopsy is required for staging.** PROGNOSIS: 5 year survival for the following sub-types. embryonal- 80% Alveolar- 60% Botryoid- uniformly fatal, less than 30% of patients live 5 years from the time of diagnosis Pleomorphic- 25%

Answer 284

Head/neck, genitourinary system, or retroperitoneum.

Answer 285

MRI- like most other STS dark on T1 and bright on T2. Need CT of chest for staging. Histology differs depending on subtype: **embryonal-** small round blue cell, skeletal muscle like cross-striations can occur. depicted in image **alveolar-** poorly differentiated round cells with multinucleated giant cells. Cellular aggregates are surrounded by dense fibrous septae. **pleomorphic-** multiple cell types are present. difficult to differentiate from other pleomorphic sarcomas. IMMUNOHISTOCHEMISTRY +: MyoD1, myoglobin, myosin, desmin, and vimentin.

Answer 286

Chemotherapy alone in select patients with widespread metastatic disease. common agents include vincristine, dactinomycin, and cyclophosphamide. Radiation for unresectable tumors or close/positive margins. **wide surgical excision with chemotherapy is stnadar of care.** **chemotherapy is not effective for adult rhabdomyosarcoma. Use surgery and radiation.**

Answer 287

A fibrogenic lesion that is the most locally invasive of all benign soft tissue tumors. Female \> male 3:1. Found in patients 25-35 years of age. Higher incidence in familial adenomatous polyposis (FAP) and Gardner syndrome (4-30%) Most common shoulder (20%) \> chest wall/back (17%) \> thigh (13%). \>50% are extra-abdominal. May have multiple lesions in the same extremity. Appears in sites of previous surgery or scared **elevated levels of beta catenin in all tumors.** trisomy in chromosome 8 or 20.

Answer 288

Dupuytrens contractures, Ledderhose disease, FAP, and Gardner syndrome High risk of recurrence and lesions are highly unpredictable. No risk of metastatis or malignant transformation unless related to radiation.

Answer 289

enlarging mass with possible nerve compression. Will have a distinctive **rock hard** feel on palpation because tumor is fixed to surrounding tissues. Poorly circumscribed and may be painful and limit motion around joint.

Answer 290

dark on T1 dark to isointense on T2 Gadolinium enhances appearance. Infiltrates muscle 5-10cm in size May erode bone locally

Answer 291

Gross specimen will be gritty, white, and poorly encapsulated. Micro will show **well differentiated fibroblasts,** uniform spindle cells with **elongated nuclei** and occasional mitoses. Abundant collagen Tumor infiltrates adjacent tissue. POSITIVE: **100% for estrogen receptor beta.** Somatostatin, cathepsin D, Ki-67, and c-Kit. NEGATIVE: **estrogen receptor alpha,** progesterone receptor, HER2.

Answer 292

**low dose-chemo only/famoxifen-** inoperable lesions. tamoxifen favored for failed/poor candidates for standard chemotherapy. **operative-** wide surgical resection with chemotherapy for symptomatic or recurrent lesions. Recurrence is reduced by radiotherapy. negative margins: 28% with surgery alone and 6% with addition of radiation. Positive margin: 39% surgery alone and 25% with addition of radiation.

Answer 293

Plantar fibromatosis (Ledderhose Disease) More common in males and the middle aged to elderly. Malignant transformation is rare. Recurrence is common and it usually recurs as a more agressive lesion. MRI will be dark on T1 and medium signal on T2. Will have "comb sign" on Ultrasound. Can be treated with observation if small or not very symptomatic Excision for symptomatic +/- radiation. **Total fasciectomy is prefferred due to risk of recurrenct.** 0-50% risk with total fasciectomy compared to 57-100% with local excision.

Answer 294

Common reactive lesion that usually occurs in upper extremities of young people age 15-35 years. **most common fibrous soft tissue lesion.** common locations volar forearm, back, chest wall, head, and neck. May be painful or painless. Rapidly enlarging over 1-2 weeks. Generally not bigger than 2cm. MRI: most commonly superifical mass with extension along fascial planes. avid enhancement with gadolinium. HISTOLOGY: short irregular bundles and fascicles. Dense reticulum network. small amounts of mature collagen. Marginal resection.

Answer 295

rare low-grade fibrogenic cutaneous sarcoma that occurs in early to midadult life. Variants include: **Bednar tumor-** pigmented variant that is 7.5x more common in African Americans. **Fibrosarcomatous-** more aggressive variant with poor prognosis. Patients aged 20-50 yrs old. Slightly more common in males. 2:1 African Americans to Caucasians. Most common locations trunk \> proximal extremities \> head/neck

Answer 296

t(17;22)- encodes for PDFG-beta chain (PDGFB)/collagen type I alpha 1 (COL1A1) fusion protein. distant mets is rare \<5%: lung is the most common site. usually preceded by multiple local recurrences. Worse prognosis is seen with: regional lymph node involvement, fibrosarcomatous variant, age \> 50 yrs Worse prognosis with the following histologic features: high number of mitotic figures, increased cellularity, DNA aneuploidy, TP53 gene overexpression.

Answer 297

Biopsy is required for diagnosis. Classically appears as uniform fibroblasts arranged in storiform pattern around an inconspicuous vasculature. **Bednar-** variant has scattered melanin-containing dendritic cells. **Fibrosarcomatous-** variant has a characteristic herringbone pattern.

Answer 298

**Nonoperative-** adult patients with unresectable, recurrent, and/or metastatic DFSP. uses **imatinib** which inhibits PDGF-receptor tyrosine kinase. 65% response rate. No response in patients who lack the t(17;22) mutation. **Operative-** wide surgical resection +/- adjuvant radiation therapy. Done for patients with resectabel DFSP. Obtain 2-3cm margins. Need to dissect deep to and excise all tissue including the fascia. 15.7% recurrence for lesions on the body. 51.8% recurrence rate for lesions on the head/neck.

Answer 299

**Spindle cell lipoma-** common in males 45-65 years. Treated with marginal excision. **Pleomorhpic lipoma-** common in middle aged patients. May be confused with liposarcomas. **Angiolipoma-** unique in that it is painful when palpated. Often present with small nodules in the upper extremity. **Intramuscular lipoma-** Often symptomatic and requires marginal resection **Hibernoma-** tumor of bown fat. Affects younger patients (20-40 yrs). See image.

Answer 300

Bright on T1 Bright on T2 Dark on STIR of fat saturated sequences.

Answer 301

In general show bland acellular stroma with neoplastic cells that lack cellular atypia. Hibernoma are reddish brown becuase of rich vascular supply in addition to high numbers of mitochondria. **Spindle cell lipoma-** mucoid matrix with varying numer of birefringent collagen fibers. Will see spindle cells. **Pleomorphic lipoma-** lipocytes, spindle cells, and scattered atypical giant cells. **Angiolipoma-** mature fat cells with nests of small arborizing vessels. **Intramuscular lipoma-** lipoblasts and muscle infiltration. See image.

Answer 302

symptomatic. mass is rapidly growing. Tumors located deep to the fascia or in the retroperitoneum. These have a higher likelyhood to become atypical lipomatous tumors. In the retroperitoneum referred to as well-differentiated liposarcoma. In the extremities referred to as atypical lipomas Spindle cell/pleomorphic lipomas are treated by marginal resection. **Recurrence is uncommon \< 5%**

Answer 303

Signet ring-type cell

Answer 304

Older individuals 50-80 yrs Males more than females More common in the lower extremity than upper extremity. Usually occur deep to fascia and are common in the retroperitoneum.

Answer 305

Well-differentiated liposarcoma- amplification MDM2 Myxoid liposarcoma -\> t(12;16) Metastasis risk correlates with grade/sub-type of liposarcoma: low grade (well differentiated) \<1% Intermediate grade (myxoid) 10-30%. High grade rate of \>50% PROGNOSIS: Well differentiated \<10% local recurrence and almost complete survival Intermediate and high grade 20% local recurrence but 5 year survival is 25-50%

Answer 306

Myxoid liposarcoma. Most common- 50% of all liposarcomas.

Answer 307

CT chest/Abd/Pelvis they have a tendency for abnormal metastasis outside of the lungs, such as spread to the retroperitoneum.

Answer 308

Well-differentiated or atypical will loo similar to lipomas. Bright on T1 and dark on T2. (isointense with fat). High grade liposarcomas will be similar to all other sarcomas. Dark on T1 and Bright on T2

Answer 309

**marginal resection without radiotherapy-** well differentiated liposarcoma **wide surgical resection with adjuvant radiotherapy-** Intermediate and high grade liposarcomas Radiation decreases recurrence. Chemotherapy generally not used.

Answer 310

Rare complications of soft tisse hemangioma caused by entrapped platelets that can lead to a possibly fatal coagulopathy.

Answer 311

More common in patients \<30 years of age. Common in the hand intramuscular is commonly found deep in the lower extremities. Most commonly found as isolated lesions, except for diffuse hemangioma (a rare childhood form which extensively involves a single limb. No incidence of malignant transformation. Infantile forms involute by age 7. Mass will vary in size depending on activity level and between supine and standing position.

Answer 312

Radiographs may show small phleboliths (calcifications) inside the lesion and erosion into adjacent bone. MRI WITH GADOLINIUM: Increased signal on both T1 and T2 sequences. Heterogeneous lesion with numerous small blood vessels adn fatty infiltration (bag of worms). Focal areas of low signal are a sing of blood flow or calcifications. **Helps differentiate these benign lesions from arteriovenous malformations and angiosarcomas.**

Answer 313

gross speciment will vary from red to tan to yellow. No malignant cells. Many vascular dilations with large nuclei filled with erythrocytes. Vascular lumens infiltrated with muscle fibers Cavernous type shows large vessels with lots of fatty tissue.

Answer 314

First line and childhood lesions -\> observation, NSAIDs, vascular stockings, and activity modification. Large painful lesions that fail the above can undergo sclerotherapy of embolization with IR. OPERATIVE: Small lesions of the hand -\> marginal excision Wide surgical resection for lesions resistant to nonoperative management.

Answer 315

Male \> female elderly 60% near long bones Osseous involvement in \<10% Poor, high local failure rate and amputation is often required. Propensity for lymphatic spread. Metastases to lung is common.

Answer 316

Vascular channels with variable degrees of anaplasia. Malignant cells associated with vascular structures.

Answer 317

Wide surgical excision is treatment of choice. Often end up with amputation to achieve local control of disease. Relatively insesitive to chemotherapy and radiation.

Answer 318

Not glomus tumor its **squamous cell carcinoma.**

Answer 319

**primary risk factor is exposure to ultraviolet radiation.** actinokeratosis Chronic osteomyelitis Marjolin's ulcer is a squamous cell carcinoma resulting from chronic draining wounds or burns or scars. Relatively high incidence of mets. Higher than basal cell carcinoma. Also metastases to lymph nodes.

Answer 320

**Wide surgical resection +/- skin graft +/- radiation** standard of treatment. adjunctive radiatio when: lesions \>2cm wide. 4mm deep. perineural invasion. Lymph node metastases. **Mohs microsurgery-** indicated for smaller lesions. High cure rate. Lymph node biopsy may be necessary.

Answer 321

Rare benign tumor of the glomus body(perivascular temperature regulating structure that is frequently located at the tip of a digit) that often occurs in the subungual region Also called a paraganglioma. May involve soft tissue or bone. Patients 20 to 40 years of age. 75% occur in hand. 50% are subungual. 50% have erosions of distal phalanx. Less common locations are palm, wrist, forearm, and foot.

Answer 322

TRIAD: paroxysmal pain, exquisite tenderness to touch, and cold intolerance. Physical exam: small bluish nodule. Often difficult to see especially when it is under the nail. Nail ridging or discoloration is common. **Love test:** pressure to the area with a pinhead elicits exquisite pain. 100% sensitive and 78% accurate. **Hildreth test:** tourniquet inflation reduces pain/tenderness and abolishes tenderness to the love test. 92% sensitive and 91% specific.

Answer 323

On radiographs can see pressure erosion of the underlying bone and an associated deformity of the bone cortex. MRI: dark on T1 and bright on T2 Well defined lesion with samll round cells and dark nuclei. associated small vessels in a hyaline/myxoid stroma Can show gland-like or nest structures, separated by stromal elements.

Answer 324

Marginal excision is curative. Done if symptoms affecting quality of life. Recurrence is uncommon (20%). Can become malignant. Reconstruction of nail bed contour with autologous fat graft is done for large defects after resection.

Answer 325

rare malignant slow growing nodular soft tissue tumor. 2:1 Male to female age 10-35 years **Most common soft tissue sarcoma of the hand and wrist.** also occurs in the forearm, buttock/thigh, knee, and foot. Can be deep( attached to tendons or fascia) or superficial where is can ulcerate and mimic skin carcinoma, rheumatoid nodules, or granulomas. Regional lymph node mets is common. Lung mets can also occur. **extremely poor prognosis**

Answer 326

RADIOGRAPHS: erosion of adjacent bone is sometimes foung. Calcification in 10-20% MRI: dark on T1 and bright on T2. May visualize it attached to tendon sheath. HISTOLOGY: nodular pattern with central necrosis within granulomatous area. epithelial appearance with ovoid or polygonal cells with eosinophilic cytoplastm. dense hyalinized collage deposits intercellularly Keratin positive staining.

Answer 327

Wide excision with adjuvant radiotherapy for all operable tumors. **perform a sentinel lymph node biopsy to evaluate for regional lymph node metastasis.** Amputation may be necessary to prevent spread of disease in cases of multiple recurrences.

Answer 328

**Benign** soft tissue tumor that presents as a slow growing deeply seated mass confined to skeletal muscle. Likely develop from premature mesenchymal stem cells which differentiate into benign fibroblasts. 40 to 60 year olds with slight female predilection. Commonly located in thigh, shoulder, buttock, or upper arm. Mets are uncommon. Prongosis is good.

Answer 329

**Mazabraud's syndrome-** a syndrome characterized by multiple intramuscular myxomas associated with monostotic or polyostotoic fibrous dysplasia. **Myxoid liposarcomas-** important to differentiate from a myxoid liposarcoma which occurs in an intermuscular location.

Answer 330

MRI: Will have homogenous appearance. Dark T1 and Bright on T2. **key is the intramuscular location!** **myxoid liposarcoma will occur in an intermuscular location.** HISTOLOGY: characterized by a bland and hypo-cellular myxoid stroma No cellular atypia or atypical mitosis.

Answer 331

observation for asymptomatic lesions. Marginal excision for symptomatic lesions. Recurrence and mets is very uncommon.

Answer 332

Lucency of the medial corticla border of the metaphysis. Pathognomonic for focal fibrocartilaginous dysplasia? Occurs in humerus, ulna, and femur. Can spontaneously resolve but often requires corrective osteotomy.

Answer 333

6 Gy 60 Gy 30 Gy

Answer 334

Proton beam radiotherapy offers the added value of avoiding the exit dose and therfore is often used in the context of spinal column tumors or tumors immediately adjacent to the spinal elements. Conventional radiation most often utilized photon radiotherapy.

Path Flashcards

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