Bone and soft tissue tumors

Question 1

What does CT assess in upper extremity tumors?

Answer 1

It evaluates bone destruction and calcified lesions.

Question 2

How does clonality distinguish neoplasms from benign growths like Dupuytren’s?

Answer 2

Benign conditions (e.g., Dupuytren’s) are polyclonal; neoplasms are monoclonal.

Question 3

Is a tourniquet safe for upper extremity neoplasm surgery, and how should it be applied?

Answer 3

Yes, use it with gravity exsanguination (arm elevation), not an Esmarch bandage.

Question 4

How should an incision be oriented for an upper extremity mass biopsy?

Answer 4

Longitudinally, to incorporate into the final excision or amputation.

Question 5

Should you dissect around or split the muscle during an upper extremity biopsy?

Answer 5

Split the muscle sharply to avoid seeding other compartments.

Question 6

Are drains recommended after an open biopsy of an upper extremity mass?

Answer 6

No, they can seed tumor cells along tracts; use diligent hemostasis instead.

Question 7

What causes an epidermal inclusion cyst?

Answer 7

Epidermal cells embed in the dermis, usually due to trauma.

Question 8

Where do epidermal inclusion cysts typically occur, and how are they treated?

Answer 8

In glabrous skin of the palms and fingertips (often perionychium); treat with complete excision including the punctum.

Question 9

What is a glomus tumor?

Answer 9

A benign hamartoma from the thermoregulatory neuromyoarterial apparatus in the stratum reticulare.

Question 10

What symptoms indicate a subungual glomus tumor, and how is it treated?

Answer 10

Severe pain, cold sensitivity, tenderness, nail deformity, and discoloration; treat by removing the nail plate and excising the tumor completely.

Question 11

What is a pyogenic granuloma, and who does it most commonly affect?

Answer 11

A rapidly growing, vascular, friable nodule, often on fingertips; most common in young adults, especially post-pregnancy.

Question 12

What are the two most common hand tumors or masses?

Answer 12

1. Ganglions; 2. Giant cell tumors.

Question 13

What is the predominant cell type in giant cell tumors of the hand?

Answer 13

Histiocytes.

Question 14

Where do giant cell tumors of the hand typically originate?

Answer 14

Flexor tendon sheath.

Question 15

How are giant cell tumors of the hand treated?

Answer 15

Complete excision, including the stalk if present.

Question 16

How do neurofibromas and neurilemmomas differ?

Answer 16

Neurofibromas arise within nerve fascicles; neurilemmomas (schwannomas) arise from Schwann cells on the nerve surface.

Question 17

How are neurofibromas and neurilemmomas treated surgically?

Answer 17

Neurofibromas require fascicle transection; neurilemmomas can be shelled out.

Question 18

What is the most common benign nerve tumor of the upper extremity?

Answer 18

Neurilemmoma (schwannoma).

Question 19

What condition is suggested by multiple upper extremity neurofibromas and café-au-lait spots?

Answer 19

Neurofibromatosis type 1 (NF1, von Recklinghausen disease).

Question 20

What condition is likely in a patient with bilateral acoustic schwannomas?

Answer 20

Neurofibromatosis type 2 (NF2), rarely with neurofibromas.

Question 21

What studies differentiate neurofibromas from neurilemmomas?

Answer 21

MRI and nerve conduction studies.

Question 22

How are fibromatosis and juvenile aponeurotic fibromas treated?

Answer 22

Wide excision with skin grafting or free tissue transfer; high recurrence risk.

Question 23

What is infantile digital fibromatosis, and when does it present?

Answer 23

A benign condition in children (5 months–6 years) with firm, nontender nodules on the dorsal/lateral fingers.

Question 24

What histologic features characterize infantile digital fibromatosis?

Answer 24

Interlacing fibroblasts with intracytoplasmic eosinophilic inclusion bodies.

Question 25

How is infantile digital fibromatosis treated?

Answer 25

Wide excision with full-thickness skin grafting if needed.

Question 26

What is the main challenge with desmoid tumors?

Answer 26

High recurrence rate, especially in females.

Question 27

How are upper extremity AVMs treated?

Answer 27

Ligation of feeding vessels and complete excision, often with preoperative embolization.

Question 28

Which benign bone tumor is most common in the hand?

Answer 28

Enchondroma.

Question 29

Where do enchondromas commonly occur in the hand?

Answer 29

Proximal phalanx, metacarpal, and middle phalanx.

Question 30

What is Ollier’s disease?

Answer 30

A nonhereditary condition of multiple unilateral enchondromas.

Question 31

What defines Maffucci syndrome?

Answer 31

Multiple enchondromas with hemangiomas.

Question 32

What is the lifetime risk of malignant transformation for a solitary enchondroma?

Answer 32

Less than 5%.

Question 33

What malignancy can enchondromas transform into?

Answer 33

Chondrosarcoma.

Question 34

How do enchondromas typically present?

Answer 34

Often as pathologic fractures causing pain.

Question 35

How are enchondromas treated?

Answer 35

Curettage and bone grafting; allow fractures to heal first if present.

Question 36

What is a periosteal chondroma?

Answer 36

A benign cartilaginous tumor at the metaphyseal-diaphyseal junction of the phalanx, similar to enchondroma.

Question 37

What age group is most affected by unicameral bone cysts, and are they exclusive to this group?

Answer 37

5–10 years, almost exclusively in children.

Question 38

How do unicameral bone cysts typically present?

Answer 38

As incidental radiographic findings or pathologic fractures.

Question 39

What is the nonsurgical treatment for unicameral bone cysts?

Answer 39

Intralesional corticosteroid injection.

Question 40

What are aneurysmal bone cysts, and where do they occur?

Answer 40

Blood-filled cysts in the metacarpal metaphysis growing toward the physis.

Question 41

What age group is most affected by aneurysmal bone cysts, and what are the symptoms?

Answer 41

Second decade of life; swelling and pain, often post-injury.

Question 42

How are aneurysmal bone cysts treated?

Answer 42

Curettage and bone grafting due to their erosive nature.

Question 43

What is the structure of an osteochondroma?

Answer 43

A bone stalk with a cartilaginous cap growing from the metaphysis in skeletally immature patients.

Question 44

When is excision necessary for osteochondromas?

Answer 44

Only if symptomatic, as malignant transformation is rare.

Question 45

What symptoms characterize osteoid osteomas?

Answer 45

Nighttime pain relieved by NSAIDs.

Question 46

How do osteoid osteomas appear on imaging?

Answer 46

A sclerotic nidus with a lucent halo, less than 1 cm in diameter.

Question 47

What histologic features define osteoid osteomas?

Answer 47

A hypervascular nidus of osteoblasts with surrounding cortical reactive bone.

Question 48

How are osteoid osteomas treated?

Answer 48

Curettage and bone grafting.

Question 49

What is an osteoblastoma, and how does it differ from an osteoid osteoma on imaging?

Answer 49

A hypervascular nidus of osteoblasts with reactive bone; imaging shows a sclerotic nidus with a lucent halo, greater than 1 cm.

Question 50

What are the clinical features of a giant cell tumor of bone in the hand?

Answer 50

Gradual swelling, pain, and sometimes pathologic fracture, often in the distal radius.

Question 51

Do giant cell tumors of bone have malignant potential?

Answer 51

Yes, they can metastasize, most commonly to the lung.

Question 52

How do giant cell tumors of bone appear on radiographs?

Answer 52

Lytic lesions without new bone formation, encroaching on but not penetrating the joint surface.

Question 53

How are giant cell tumors of bone surgically treated?

Answer 53

Wide excision with joint reconstruction if needed.

Question 54

What is the most common malignant hand tumor?

Answer 54

Squamous cell carcinoma (SCC).

Question 55

Which benign peripheral nerve sheath tumor is more prevalent in the hand and wrist: neurofibromas or Schwannomas?

Answer 55

Schwannomas ## Footnote (Angelini et al., 2018)

Question 56

Are neurofibromas typically solitary or multiple when presenting in the upper limb?

Answer 56

**Neurofibromas are typically solitary**, though multiple presentations are often linked to neurofibromatosis type 1 (NF1), which occurs in less than 5% of cases. ## Footnote (Woodruff et al., 1997)

Question 57

On which side of the forearm are Schwannomas most commonly located: flexor or extensor?

Answer 57

Schwannomas are most commonly located on** the flexor side of the forearm,** correlating with the distribution of major nerves like the median and ulnar. ## Footnote (Kim et al., 2003)

Question 58

Why is neurological deficit more frequent after neurofibroma resection compared to Schwannoma resection?

Answer 58

Neurofibromas are intraneural and infiltrative, often necessitating nerve sacrifice with a 45% deficit rate, while Schwannomas are eccentric and encapsulated, enabling enucleation with a 5% deficit risk. ## Footnote (Kim et al., 2007)

Question 59

Does current evidence support malignant degeneration as a significant risk in Schwannomas?

Answer 59

Malignant degeneration in Schwannomas is extremely rare and not well-established, with most malignant peripheral nerve sheath tumors arising de novo or from neurofibromas in NF1. ## Footnote (Farid et al., 2014)

Question 60

What is the most commonly affected bone in the hand by enchondromas?

Answer 60

The proximal phalanx is the most commonly affected, not the metacarpal bone. Studies indicate that 69.7% of hand tumors, including enchondromas, occur in the phalanges, with the proximal phalanx being the most frequent site.

Question 61

Does delaying treatment of an enchondroma until after an undisplaced pathological fracture heals affect clinical outcomes?

Answer 61

No, outcomes are similar whether treatment occurs immediately or after healing. Research shows no significant differences in consolidation time, recurrence rate, or functional outcomes based on timing.

Question 62

Do bone grafts reduce the local recurrence rate of hand enchondromas after curettage?

Answer 62

**No, bone grafts do not influence recurrence rates.** Evidence highlights that the thoroughness of curettage, not the use of grafts, is the key factor in preventing recurrence.

Question 63

What is the estimated risk of malignant transformation in a patient with Ollier’s disease?

Answer 63

**The risk is approximately 25-30%, **not 10%. Clinical studies consistently report this higher range, emphasizing the need for vigilant monitoring.

Question 64

Are multiple enchondromas with phleboliths on radiographs indicative of Ollier’s disease or Maffucci’s syndrome?

Answer 64

These findings indicate **Maffucci’s syndrome**, not Ollier’s disease. Research confirms that Maffucci’s syndrome features both enchondromas and hemangiomas (marked by phleboliths), while Ollier’s disease involves only enchondromas.