Pathoma Flashcards
1
Q
bartholin cyst
A
- cystic dilation of bartholin gland
- presents as unilateral, paiful cystic lesion adjacent to vagina
2
Q
condyloma
A
- warty neoplasm
- most commonly due to HPV 6, 11 (low risk)
- characterized by koilocytic change
3
Q
koilocytes
A
- characterizing feature of HPV-infected cells
- “empty cell”; actively synthesizing virus (infectious)
4
Q
lichen sclerosis
A
- thinning of epidermis and fibrosis of dermis
- presents as leukoplakia with parchment-like vulvar skin
- benign; associated with slightly increased risk for SCC
5
Q
lichen simplex chronicus
A
- hyperplasia of vulvar squamous epithelium
- presents as leukoplaki with thick, leathery vulvar skin
- benign; no increased risk of SCC
6
Q
vulvar carcinoma
A
- carcinoma arisng from squamous epithelium lining the vulva
- relatively rare
- presents as leukoplakia (biopsy to distinguish from other cuases)
-
HPV related due to HPV 16, 18→VIN
- reproductive age
-
Non-HPV related from long-standing lichen sclerosis
- elderly
7
Q
extramammary paget disease
A
- malignant epithelial cells of epidermis of vulva
- presents as erythematous, pruritic, ulcerated vulvar skin
- represents CIS usually without underlyng carcinoma
- unlike Paget’s disease of nipple
-
Distinguish from melanoma
- Paget cells: PAS+, keratin+, S100-
- melanoma: PAS-, keratin-, S100+
8
Q
adenosis
A
- focal persistance of columnar epithelium in upper vagina
- increased incidence in women exposed to DES in utero
9
Q
clear cell adenocarcinoma
A
- malignant proliferation of glands with clear cytoplasm
- rare; complication of DES-associated vaginal adenosis
- not HPV related
10
Q
embryomal rhabdomyosarcoma
A
- malignant mesenchymal proliferation of immature skeletal muscle
- rare; presents as grape-like mass protruding from vagina/penis in <5 y.o.
-
rhabdomyoblast (characteristic cell) has cytoplasmic cross-striations
- desmin+ and myogenin+
11
Q
vaginal carcinoma
A
- carcinoma arising from squamous lining of vaginal mucosa
- high risk HPV (16,18, 31, 33)→VAIN
- lymphatic involvement is embryonal
- lower 1/3→inguinal nodes (urogenital sinus derived)
- upper 2/3→regional iliac nodes (mullerian duct derived)
12
Q
healthy cervix
A
- exocervix (visible): nonkeratinizing squamous
- endocervix: single layer of columnar cells
- transformation zone: portion of cervix where more cancer originates
- junction moves up the canal with age
13
Q
HPV
A
- STD DNA virus that infects lower genital tracts esp. transformation zone of cervix
- infection usually eradicated by acute inflammation
- persistant infection→increased risk for CIN
- high risk: 16,18,31,33
- loss of tumor suppression (E6→degrades p53; E7→inactivates Rb)
- low risk: 6, 11
- quadvalent vaccine: L1 protein (DNA for viral capsule); protects against: 6,11,16,18
14
Q
CIN
A
- koilocytic change, disordered cellular maturation, nuclear atypia, and increased mitotic activity in cervical epithelium
-
classically progresses through CIN1,2,3,CIS→invasive SCC
- takes approx. 10-20 years
- progession not inevitable but harder to regress the higher the grade of dysplasia
15
Q
cervical carcinoma
A
- invasive carcinoma that arises from cervical epithelium
- 80% SCC, 15% adenocarcinoma
- MC seen in middle-aged women
- presents with vaginal bleeding
- risk factor: high risk HPV, smoking, immunodeficiency
- AIDS defining illness
- advanced tumors→anterior uterine wall→bladder→hydronephrosis with postrenal failure→death
16
Q
pap smear
A
- gold standard for screening of cervical carcinoma
- 21-30: every 3 yrs
- 30-65: pap &HPV testing or pap alone every 5 yrs
- high grade dysplasia characterized by cells with hyperchromatic nucle and high nuclear to cytoplasmic ratio
- abnormal result followed by colposcopy and biopsy
17
Q
healthy endometrium
A
- proliferative phase: estrogen driven
- secretory phase: progesterone driven
- menstrual phase: loss of progesterone support
18
Q
asherman syndome
A
overaggressive D&C→ secondary amenorrhea due to loss of basalis (regenerative layer) and scarring
19
Q
anovulatory cycle
A
lack of ovulation→estrogen driven proliferation without subsequent progesterone driven secretory phase
- growth on top of growth→overgrowth of blood supply
- common cause of dysfunctional bleeding esp. during menarche and menopause
20
Q
acute vs. chronic endometritis
A
- acute: bacterial infection usually due to retained parts of conception→fever, abnormal bleeding, pain
- chronic: chronic inflammation characterized by plasma cells; usually due to retained parts of conception, chronic pelvic inflammatory disease (e.g., chlamydia), IUD, TB→bleeding, pain, infertility
21
Q
endometrial polyp
A
- hyperplastic protrusion of endometrium
- can arise as side effect of tamoxifen (anti-estrogenic effect on breast, weak pro-estrogenic effects on endometrium)
22
Q
endometriosis
A
- endometrial glands and stroma outside of uterine endometrium
- most likely due to retrograde menstruation
- MC site of involvement is ovary→ chocolate cysts
- fallopian tube→ gun-powder nodules→ increased risk for ectopic pregnancy
- increased risk for carcinoma at site of endometriosis
23
Q
endometrial hyperplasia
A
- hyperplasia of endometrial glands relative to stroma as a result of unopposed estrogen
- presents as postmenopausal bleeding
- classified based on growth (simple vs. complex) and degree of atypia
- atypia→cancer/cancer associated→hysterectomy
24
Q
endometrial carcinoma
A
- malignant proliferation of endometrial glands
- MC invasive carcinoma of female genital tract (but unlikely killer)
- hyperplasia (75%): related to estrogen exposure; ~60 y.o.; endometrioid histology
-
sporadic (25%): no evident precursor lesion; ~70 y.o.; serous histology characterized by papillary structures with psammoma body
- p53 mutation is common→aggressive
25
psamomma body
concentrically layered calcifications that occur with:
* papillary carcinoma of thyroid
* meningioma
* **serous tumors of endometrium or ovary**
* mesothelioma
26
leiomyoma (fibroids)
* **benign** neoplasic proliferation of smooth muscle in myometrium; MC tumor in women
* related to estrogen exposure
* premenopause
* often occur in multiples
* enlarge during pregnancy, shrink after menopause
* appear as **well-defined white whorled masses**
* MC symptom: nothing
27
leomyosarcoma
* **malignant** proliferation of smooth muscle of myometrium
* **arises de novo**
* seen in postmenopausal women
* appears as single yellowish lesion with areas of necrosis and hemorrhage
28
healthy ovarian follicle
* functional unit of ovary; consists of oocyte + granulosa and theca cells
* LH→ theca→ androgen production
* FSH→ granulosa→ conversion of androgen to estradiol
* estradiol surge→ LH surge→ ovulation
29
polycystic ovarian disease
multiple ovarian follicular cysts due to hormone imbalance (increased LH, low FSH; LH:FSH\>2)
* excess androgen production→hirsutism
* androgen→ estrone in adipose tissue→decreases FSH→cystic degeneration of follicles
* **high levels of estrone increase risk for endometrial cancer**
30
surface epithelial tumors of ovary
* MC type of ovarian tumor (70%); clinically present late with vague symptoms→poor prognosis
* tend to spread locally
* use CA125 to monitor treatment response
* derived from coelomic epithelium
* 2 MC subtypes are serous and mucinous
* **benign tumors (cystadenomas):** single cyst with simple flat lining; occur in premenopausal women
* **malignant tumors (cystadenocarcinomas):** complex cysts with shaggy lining; occur in postmenopausal women
* **borderline tumors:** mixed features, still carry metastatic potential
* endometrioid tumor: usually malignant; may arise from endometriosis
* brenner tumor: usually benign; composed of bladder-like epithelium
31
germ cell tumors
* 2nd MC type of ovarian tumor (15%)
* tumor sbtypes mimic normal germ tissues
* fetal: cystic teratoma, emryonal carcinoma
* oocyte: dysgerminoma
* yold sac: endodermal sinus tumor
* placenta: choriocarcinoma
32
cystic teratoma
* MC germ cell tumor in females; usually **benign**
* ****malignant if immature tissue or somatic malignancy is present in the tumor
* struma ovarii: teratoma composed of thyroid
* cystic; composed of fetal tissue derived from 2-3 embryologic layers
33
dysgerminoma
* composed of large cells with clear cytoplasm and central nulclei (resemble oocyte)
* serum LDH may be elevated
* malignant but responds well to radiotherapy
34
endodermal sinus tumor
* MC germ cell tumor in children
* malignant tumor that mimics the yolk sac
* presence of **Schiller-Duval bodies (glomerulus-like)**
* serum AFP may be elevated
35
choriocarcinoma
* **malignant;** small hemorrhagic tumor that mimics placental tissue except **villi are absent**
* early hematogenous spread→tiny tumor in ovary with massive tumors elsewhere
* high ß-hCG
36
embryonal carcinoma
malignant tumor composed of large primitive cells; aggressive with early metastasis
37
sex-cord stromal tumors
* **granulosa-theca cell tumor:** often produces estrogen→ signs of estrogen excess
* post menopause is most common setting→endometrial hyperplasia with abnormal bleeding
* **sertoli leydig cell tumor:** mimics sex-cord stromal cells of testicle, has characteristic Reinke crystals; may produce androgen
* **fibroma:** benign tumor of fibroblasts, associated with **Meigs syndrome (pleural effusions and ascites)**
38
krukenberg tumor
metastatic mucinous tumor that involves both ovaries; most commonly due to metastatic gastric carcinoma
* bilaterality helps distinguish from primary mucinous carcinoma of ovary
39
pseudomyxoma peritonei
massive amounts of mucus in peritoneum (jelly belly) due to a mucnous tumor of appendix usually with metastasis to the ovary
40
ectopic pregnancy
* implantation of fertilized ovum at a site other than uterine wall (MC: lumen of fallopian tube)
* key risk factor: scarring from PID or endometriosis
* lower quadrant abdominal pain a few weeks after missed period
* **surgical emergency**
41
spontaneous abortion
* miscarriage of fetus \<20 wks gestation
* common (1/4 of recognizable pregnancies); MC due to chromosomal abnormalities (esp. trisomy 16)
* vaginal bleeding, cramps, passage of fetal tissue
42
placenta previa
implantation of placenta in lower uterine segment→placenta overlies cervial os; often requires C-section
43
placental abruption
separation of placenta from decidua prior to delivery of fetus; common cause of stillbirth
44
placental accreta
"placenta gets stuck" due to improper implantaion of placent into myometrium with little/no intervening decidua
45
what are 8 common teratogens and their effects?
1. **alcohol:** MCC of mental retardation, facial abnormalities, microcephaly
2. **cocaine:** intrauterine growth retardation and placental abruption
3. **thalidomide:** limb defects
4. **cigarette smoke:** intrauterine growth retardation
5. **isotretinoin:** spontaneous abortion, hearing/visual impairment
6. **tetracycline:** discolored teeth
7. **warfarin: f**etal bleeding
8. **phenytoin:** digit hypoplasia, cleft lip/palate
46
preeclampsia
* pregnancy induced HTN, proteinuria, and edema usually in 3rd trimester
* due to abnormality of maternal-fetal vascular interface in placenta (resolves with delivery)
* + seizures=eclampsia
* HELLP is preeclampsia involving liver (**h**emolysis, **e**levated **l**iver enzymes, **l**ow **p**latelets)
* **HELLP and eclampsia warrant immediate delivery**
47
SIDS
* death of healthy infant (1mo-1yr) without obvious cause; usually occurs during sleep
* risk factors: sleeping on stomach, second-hand smoke, prematurity
48
hydatidiform mole
* abnormal conception characterized by swollen and edematous villi with prolifersation of trophoblasts (grow abnomal placental tissue instead of a baby)
* uterus expands but is much larger and ß-hCG is much higher than expected date of gestation
* presents in 2nd trimester with passage of grape-like masses through vagina→D&C
* monitor ß-hCG to ensure adequate removal and screen for choriocarcinoma
49
partial vs. complete hydatidiform mole
* **partial:** normal ovum, fetal tissue, normal and hydropic villi, focal proliferation around hydropic villi, minimal risk for choriocarcinoma
* **complete:** empty ovum, no fetal tissue, hydropic villi, difuse, circumferential proliferation around hydropic villi, 2-3% risk of choriocarcinoma
50
normal breast tissue
* modified sweat gland derived from skin; develops along milk line
* **luminal cell layer:** inner cell layer lining ducts and lobules
* **myoepithelial cell layer:** outer cell layer lining ducts and lobules
51
acute mastitis
* bacterial infection of the breast usually due to S. aureus
* associated with breast-feeding
* purulent discharge
52
periductal mastitis
* inflammation of subareolar ducts usually seen in smokers
* relative vit. A deficiency→ lose ability to mainitain this highly specialized epithelium→ squamous metaplasia→ keratin production and blockage→ **subareolar mass with nipple retraction**
* not associated with lactation
53
mammary duct ectasia
inflammation with dilation of the subareolar ducts→ **green-brown nipple discharge;** rare
54
fat necrosis of the breast
* usually related to trauma
* presents as a mass or abnormal calcifcation on mammography
* biopsy: necrotic fat with associated calcifications and giant cells
55
fibrocystic change
* MC change in premenopausal breast, thought to be hormone mediated
* presents as vague irregularity ("lumpy breasts")
* cysts have **blue dome** appearance on gross exam
* **benign** but some fibrocystic-related changes are associated with increased risk for invasive carcinoma
* fibrosis, cysts, **apocrine metaplasia**: no increased risk
* ductal hyperplasia and sclerosing adenosis: 2x risk
* atypical hyperplasia: 5x risk
56
intraductal papilloma
* benign papillary growth, usually into a large duct
* characterized by fibrovascular projections lined by **epithelial (luminal) and myoepithelial cells**
* presents as **bloody nipple discharge in premenopausal woman**
* must be distinguished from papillary carcinoma
57
intraductal papilloma vs. papillary carcinoma
* intraductal papilloma
* 2 types of cells (luminal and myoepithelial)
* premenopausal woman
* papillary carcinoma
* epithelial cells only
* post menopausal women
58
fibroadenoma
* tumor of fibrous tissue and glands
* MC benign neoplasm of breast, MC tumor in premenopausal women
* **well-circumscribed, mobile marble-like mass**
* **estrogen sensitive**
59
phyllodes tumor
* fibroadenoma-like tumor with overgrowth of fibrous component
* **leaf-like projections** seen on biopsy
* can be malignant
60
breast cancer
* represents only 10% of breast lumps
* MC carcinoma of women by incidence
* 2nd MC cause of cancer mortality in women
61
DCIS
* malignant proliferation of cells in ducts with **no invasion of basement membrane**
* often detected as calcification on mammography
* histological stubtypes based on architecture
* camedo type: high-grade cells with necrosis and dysrophic calcification in center of ducts
62
paget's disease of the breast
* DCIS that extends up to the ducts to involve the skin of the nipple
* 50% of the time it is assocated with underlying **invasive** cancer
63
invasive ductal carcinoma
* invasive carcinoma that classical forms duct-like structures
* MC invasive carcinoma of the breast (\>80%)
* presents as mass on exam or mammography
* biopsy shows **duct-like structures in desmoplastic stroma (reaction to invasive tumor)**
* **tubular:** lack myoepithelial cells (actin-)
* **mucinous:** tumor cells in mucus pool
* **medullary:** large high-grade cells growing in sheets with associated lymphocytes and plasma cells
* **inflammatory:** carcinoma in dermal lympatics, poor prognosis
64
lobular carcinoma
* malignant proliferation of cells in lobules with no invasion of basement membrane; often multifocal and bilateral
* does not produce mass or calcification (usually discovered incidentally)
* characterized by **dyscohesive cells lacking E-cadherin**
* treat with tamoxifen; lower risk of progression to invasive carcinoma than DCIS
65
invasive lobuar carcinoma
* invasive carcinoma that characteristically **grows in single-file pattern**
* cells may exhibit **signet-ring morphology**
* no duct formation (lack of E-cadherin)
66
prognostic and predictive factors of breast cancer
* metastasis is the most important prognostic factor but because most patient present before then, spread to axillary nodes is the most useful prognostic factor
* ER+/PR+: associated with response to antiestrogenic agents
* **HER2/neu gene amplification:** associated with response to tastuzumab
* triple negative tumrors have poor prognosis
67
hereditary breast cancer
* 10% of breast cancers
* clincally features suggestive: multiple first degree relatives with BC, tumor at early age, multiple tumors
* BRCA1: associated with breast and ovarian cancer
* particularly medullary carcinoma of breast and serous carcinoma of ovary or fallopian tube
* BRCA2: associated with brast carcinoma in males
68
male breast cancer
* rare (1% of all breast cancers)
* presents as subareolar mass in older males
* MC subtype is invasive ductal carcinoma
* associated with BRCA2 and klinefelter syndrome
69
achondroplasia
* **activating mutation in FGFR3** inhibits cartilage proliferation in the growth plate
* poor endochondral bone formation, intramembranous formation ok
* short extremities with normal sized head/chest
* common cause of dwarfism
70
osteogenesis imperfecta
* congenital defect of bone formation→ structurally weak bone
* MC due to AD defect in college type I synthesis
* clinical features: multiple fractures of bone (no bruising), blue sclera, hearing loss
71
osteopetrosis
* defect of bone resorption→ abnormally thick, heavy bone that fractures easily
* due to poor osteoclast function
* multiple genetic variants; carbonic anhydrase II mutation→ loss of acidic microenvironment needed for resorption
* clinical features: fractures, bony replacement of marrow (myelophthisic process)→ anemia and thrombocytopenia, renal tubular acidosis in CAII mutation
* treatment: bone marrow transplant (osteoclasts derived from monocytes)
72
rickets
* due to low vitamin D in children→ abnormal bone mineralization, also leads to random osteoid deposition
* MC \<1 y.o. presents with pigeon breast deformity, frontal bossing, rachitic rosary, bowed legs
73
osteomalacia
* low vitamin D in adults→ inadequate mineralization leading to weak bone with increased risk of fracture
* low serum Ca, low serum PO4, high PTH, high alk phos (rises whenever there is activation of osteoblasts)
74
osteoporosis
* reduction in trabecular bone mass→ porous bone
* MC forms are senile and postmenopausal
* peak bone mass attained by 30 y.o. based on genetics, diet, exercise; lose \<1% each year
* clinical features: bone pain and fractures in weight bearing areas (e.g, vertebrae), **normal labs,** diagnose with DEXA scan
* prevention: exercise, vitamin D, Ca2+
* treatment: bisphosphonates (induce osteoclast apoptosis)
* ER therapy
* do not use glucocorticoids (worsen osteoporosis)
75
paget disease of bone
* imbalance between osteoclast and osteoblast function; usually seen \>60 y.o.
* etiology unknown (viral?)
* **localized** process
* osteoclastic→ mixed osteoblastic/clastic→ osteoblastic
* result is thick, sclerotic bone that fractures easily (looks like puzzle pieces)
* clinical features: bone pain, **increasing hat size,** lion-like facies, **MCC of isolated alk phos**
* treatment: calcitonin (inhibits clast function) and bisphosphonates (inhibits blast function)
* can lead to **high output cardiac failure** and osteosarcoma
76
osteomyelitis
* infection of marrow and bone, MCC by bacteria
* children: transient bacteremia seeds metaphysis
* adults: open-wound bacteremia seeds epiphysis
* S. aureus (90% cases)
* salmonella (sickle cell disease)
* pseudomonas (diabetes or IVDA)
* clinical features: bone pain with systemic signs of infection, lytic focus (abscess) surrounded by sclerosis of bone on x-ray
* diagnoses with blood cultures
77
avascular (aseptic) necrosis
* ischemic necrosis of bone and bone marrow
* caused by trauma or fracture (MC), sickle cell anemia, caisson disease (gas embolism)
* osteoarthritis and fracture are major complications
78
osteoma
* benign tumor of bone; MC on facial bones
* associated with **Gardner syndrome** (familial adenomatous polyposis)
79
osteoid osteoma
* benign tumor of osteoblasts that produce osteoid surrounded by a rim of reactive bone
* MC in \<25 y.o.; diaphysis of long bone
* bony mass \<2cm with radiolucent core
* **bone pain that resolves with aspirin;** worse at night
80
osteoblastoma
* \>2cm bony mass with radiolucent core
* arises in vertebrae
* presents with **bone pain that does not respond to aspirin**
81
osteochondroma
* MC benign tumor of bone
* **tumor of bone with overlying cartilage cap**
* arises from lateral projection of metaphysis; bone is continuous with marrow space
* overlying cartilage can transform to chondrosarcoma (rare)
82
osteosarcoma
* malignant proliferation of osteoblasts; arises in metaphysis of long bones (usually distal femur)
* peak incidence in teens, less commonly in elderly
* presents with pathologic fracture or bone pain with swelling
* imaging: destructive mass with **sunburst appearance** and **codman triangle (lifting of periosteum)**
* biopsy: pleomorphic cells that produce osteoid
83
giant cell tumor
* tumor comprisd of multinucleated giant cells and stromal cells arisng in **epiphysis** of long bones
* occurs in yong adults; benign but aggressive
* soap buddle appearance on x-ray
84
ewing sarcoma
* malignant proliferation of poorly differentiated cells derived from **neuroectoderm**
* arises in diaphysis of long bones in males \<15 y.o
* **onion skin** appearance on x-ray
* biopsy: round blue cells that resemble lymphocytes
* can be confused with lymphoma or chronic osteomyelitis
* 11;22 translocation is characteristic
85
(en)chondroma
* benign tumor of cartilage, usually arising in medulla (enchondroma) of small bones (chondroma grow from periosteum of bone)
* usually asymptomatic, incidentally found
* tumors are radiolucent
86
chondrosarcoma
* malignant cartilage-forming tumor that arises in medulla of pelvis or central skeleton
* endosteal scalloping on x-ray
87
chondroblastoma
* occurs in teens
* radiolucent tumor; can reoccur
* chicken wire calcification on histology
88
degenerative joint disease (osteoarthritis)
* MC type of arthritis; progressive degeneration of articular cartilage (type II collagen) due to wear and tear
* age is major risk factor; obesity and trauma
* presents with joint stiffness in morning that worsens during dat
* pathologic features
* disruption of cartilage lining articular surface; **joint mice**
* eburnation of subchondral bone
* osteophytes in **DIP (heberden) and PIP (bouchard)**
89
rheumatoid arthritis
* chronic, systemic autoimmune disease
* MC in women of late childbearing age; associated with HLA-DR4
* synovitis leading to pannus formation→ destruction of cartilage and akylosis of joint
* morning stiffness that improves with activity
* symmetical involvement of joints
* rheumatoid nodules in skin and visceral organs
* baker cyst
* labs: IgM autoantibody against Fc of IgG
90
seronegative spondyloarthropathies
* characterized by no RF, axial skeletal involvement, HLA-B27 association
* **akylosing spondyloarthritis:** sacroiliac joints and spine in young amles
* low back pain; eventually leads to bamboo spin
* extraarticular manifestations: uveitis and aortitis
* **reactive arthritis:** can't see can't pee can't climb a tree; young males after GI bug or chlamydia
* **psoriatic arthritis:** 10% of psoriasis→ sausage fingers and toes
91
infectious arthritis
* N. gonorrhoeae: young adults, MCC
* S. aureus: older children and adults
* classical involves **single joint, usually knee**
* presents as a **warm joint** with limited range of motion
92
gout
* deposition of monosodium urate crystals in tissues due to hyperuricemia (overproduction or decreased excretion of uric acid);
* synovial fluid: needle shaped crystals with negative birefringence
* primary: unknown etiology
* secondary: leukemia and myeloproliferative disorders; lesch-nyhan syndrome (x-linked HGPRT deficiency); renal insufficiency
* **acute:** podagra; alcohol or meat may precipitate
* **chronic:** tophi in soft tissue/joints; renal failure
93
pseudogout
* mimics gout clinically but is due to calcium pyrophosphate dihydrate deposits
* synovial fluid shows rhomboid crystals with weakly positive birefringence
94
dermatomyositis
* inflammatory disorder of skin and skeletal muscle
* **biopsy: perimysial inflammation (CD4 T cells) with perifascicular atrophy**
* unknown etiology; some association with carcinoma
* bilateral proximal weakness, rash of upper eyelids (heliotrope rash), malar rash, gottron papules on elbows/ knees
* labs: increased CK; **ANA+ and antiJo+**
95
polymyositis
* inflammatory disorder of skeletal muscle
* resembles dermatomyositis but **no skin involvement**
* biopsy: **endomysial inflammation (CD8 T cells) with necrotic muscle fibers**
96
x-linked muscular dystrophy
* muscle wasting and **replacement of skeletal muscle by adipose tissue**
* **duchenne:** deletion of dystrophin gene→ proximal muscle weakness by 1 y.o.; calf pseudohypertrophy; death from cardiac or respiratory failure
* **becker:** mutated dystrophin gene (clinically milder disease)
97
lipoma
* benign tumor of adipose tissue
* MC benign soft tissue tumor in adults
98
liposarcoma
* malignant tumor of adipose tissue
* MC malignant soft tissue tumor in adults
* **lipoblast** is characteristic cell (very enlarged cell with nuclear vacuoles)
99
rhabdomyoma
* benign tumor of skeletal muscle
* cardiac rhabdomyoma is associated with tuberous sclerosis
100
rhabdomyosarcoma
* malignant tumor of skeletal muscle
* MC malignant soft tissue tumor in children
* **rhabdomyoblast** is characteristic cell; **desmin+**
* common site is head and neck
* **sarcoma botryoides:** vaginal rhabdomyosarcoma in girls \<5y.o.
101
dermatofibroma
* aka benign fibrous histiocytoma; common cutaneous soft tissue lesion
* dermal proliferation of fibroblasts; sometimes occurs as a result of trauma or insect bites
* present as firm, hyperpigmented, nodules in adults; MC on lower extremities; asymptomatic; dimple when pinched
102
undifferentiated pleomorphic sarcoma
* MC sarcoma in adults; diagnosis of exclusion
* well-circumscribed mass, central necrosis
* "cartwheel" whirled pattern of cellularity
103
bone tumors by age
* _children:_ ewing sarcoma, osteosarcoma, aneurysmal bone cyst
* _young adults:_ giant cell tumor, lymphoma
* _adults/elderly:_ chondrosarcoma, myeloma/lymphoma, metastases, osteosarcoma
104
bone tumors by location
* _metaphysis:_ osteosarcoma, chondrosarcoma
* _epiphysis_: giant cell tumor
* _diaphysis:_ ewing sarcoma, chondrosarcoma
