Alikhan 6.8, 6.10, 6.12

Question 1

Dermatofibroma histology

Answer 1

Important to differentiate from DFSP. Dermal spindle cell proliferation with whorled/curly Q pattern, peripheral collagen trapping, admixed inflammatory cells, Touton-type giant cells that may contain hemosiderin and foamy histiocytes, overlying epidermal hyperplasia (“tabled rete”), basal hyperpigmentation and folliculosebaceous induction; frequently abuts but never deeply in infiltrates fat (DF only “flirts: with upper part of fat, but never penetrates it deeply; compared to DFSP); Factor 13a+, stromelysin-3+, and CD34 negative

Question 2

Dermatofibroma variants (List 5)

Answer 2

Cellular
Hemosiderotic
Lipidized/xathomatous
Aneurysmal
DF with "monster" cells

Question 3

Dermatofibrosarcoma protuberans mnemonic

Answer 3

“DFSP affects people 17 to 22 years old Called Pat,” helps remember young age (17-22) and the order of the fused genes (17 = COL1A1; 22 = PDGFB); characterized by chromosome 17 and 22 translocation; tumor of intermediate malignant potential

Question 4

Number one location for dermatofibrosarcoma protuberans

Answer 4

Shoulder, trunk, proximal extremities, groin&raquo_space; head/neck

Question 5

Dermatofibrosarcoma protuberans clinical

Answer 5

Firm plaque that expands and develops multinodular appearance

Question 6

Dermatofibrosarcoma protuberans histology highlights

Answer 6

Monotonous spindle cells with a storiform architecture in the dermis and throughout sub Q fat; characteristic “honeycomb” infiltration of fat; CD34 positive

Question 7

Treatment of dermatofibrosarcoma protuberans

Answer 7

Treat with Mohs (1% local recurrence) or wide local excision (Average of 15% local recurrence; up to 50% for head/neck lesions) with 2 cm margins; imatinib is approved for unresectable or metastatic disease; that blocks the activity of the COL1A1-PDGFB fusion protein

Question 8

Pediatric variant of dermatofibrosarcoma protuberans

Answer 8

Giant sale fibroblastoma, which occurs in early childhood, affects boys more than girls, possesses the same translocation SDFSP but favors the head and neck region; histology distinctively shows pseudovascular spaces surrounded by giant sells

Question 9

Atypical fibroxanthoma

Answer 9

A relatively common low grade, superficial (dermally based) sarcoma that arises on chronically sun damaged skin, had a neck being the number one region in elderly patients who present with a rapidly growing ulcerated red nodule

Question 10

When considering AFX (a dx of exclusion), must r/o other entities in the SLAM ddx

Answer 10

SCC (CK903 and CK5/6 +), leiomyosarcoma (desmin and SMA +), AFX, melanoma (S100 and SOX-10+)

Question 11

Looks like AFX but has deep subcutaneous in Bashan, with high rate of recurrence and metastasis

Answer 11

Pleomorphic dermal sarcoma or PDS

Question 12

Looks like AFX what is a deep sarcoma that arises in deep soft tissues such as the thigh in middle age adults; with a 5-year mortality rate of 50%

Answer 12

Undifferentiated pleomorphic sarcoma or UPS

Question 13

Angiofibroma clinical features

Answer 13

Fibrous papule, pearly penile papules, facial/periungual angiofibromas

Question 14

Multiple facial and your fibromas seen in

Answer 14

TS, MEN1, and Birt-Hogg-Dubé

Question 15

Periungual fibroma which is characteristic of TS

Answer 15

Koenen’s tumor

Question 16

Sclerotic fibroma: two testable points

Answer 16

Sclerotic collagen bundles arranged as intersecting stacks (“plywood” pattern); inconspicuous spindle cells between collagen fibers; associate it with Cowden’s syndrome

Question 17

Looks like a skin tag with “ancient change”

Answer 17

Pleomorphic fibroma

Question 18

Looks like a “cell-poor DF” with characteristic multinucleated giant cells and prominent proliferation of dilated vessels in the dermis; stains like DF; clinically looks like slowly growing, multiple, discreet but grouped red to violaceous papules usually on the lower extremities or the dorsal aspect of the hands in a woman over 40

Answer 18

Multinucleate cell angiohistiocytoma

Question 19

Epithelioid cell histiocytoma histology

Answer 19

Well circumscribed dermal proliferation of epithelial cells which resembles Spitz nevus with epidermal collarette and derma sclerosis; stains like a DF

Question 20

Middle-age adult with a digit exophytic keratotic papule with surrounding collarette

Answer 20

Acral fibrokeratoma

Question 21

Infant with multiple firm papules on dorsal lateral fingers and toes (which spares the thumb/1st toe)

Answer 21

Inclusion body fibromatosis or infantile digital fibroma; a benign condition with a 50% recurrence rate

Question 22

High-yield facts/associations of inclusion body fibromatosis or infantile digital fibroma

Answer 22

Pink inclusion body is composed of actin filaments which stain SMA + and red with trichrome

Question 23

Superficial variance of fibromatosis on the palms, soles, penis, and knuckle pads

Answer 23

Dupuytren’s, Ledderhose, Peyronie’s, holoderma

Question 24

Rapidly growing subcutaneous nodule, classically and upper extremities with possible history of trauma, with well circumscribed histology, myxoid stroma, frequent mitoses that lack of atypia (“pseudosarcoma”), extravasated RBC’s

Answer 24

Nodular fasciitis

Question 25

Infant with multiple pink – violaceous dermal and sub Q nodules in the head, which can sometimes involve bones and internal organs

Answer 25

Infantile myofibromatosis

Question 26

Neoplasm with numerous osteoclastic giant cells

Answer 26

Giant cell tumor of tendon sheath or tenosynovial giant cell tumor

Question 27

Syndromes associated with connective tissue nevi

Answer 27

TS (Shagreen patch; probably plaque on the lower back), ME – one, Buschke-Ollendorf (presents with osteopoikilosis), and Proteus syndrome