Vulva

Question 1

Extramammary Paget disease of the vulva

Answer 1

Strongly & diffusely positive for CK-7 & CEA.
Often also positive for GCDFP-15. May be also + for CK-20.

Negative for uroplakin III and HMB-45.

DDx: melanoma, pagetoid spread of either rectal adenocx or urothelial cx

Question 2

Granular cell tumor

Answer 2

Cells have voluminous eosinophilic cytoplasm, which may have granules (that are PAS+, diastase res)

Strongly and diffusely positive for S-100

Can have overlying pseudoepitheliomatous hyperplasia (which may look like SqCC)

Malignant features: prominent nucleoli, high N:C, pleomorphism, > 2 mits/10 hpf & spindling. Recur rapidly after excision & may mets widely

Question 3

Lichen sclerosus

Answer 3

Any age (usually children and postmenopausal women); usually whites

Severe pruritus & cigarette paper appearance

> DIF of adjacent normal skin needed to rule out lichen planus, pemphigus and pemphigoid

Can be associated with HPV-negative SqCC in adjacent skin

At increased risk for SqCC

Question 4

Differentiated VIN

Answer 4

Not associated with HPV

2-10% of all VIN (least common)

Postmenopausal women (vs. warty and basolid VIN, which occur 2-3 decades before that)

1/4 have hx of smoking

DDx: benign squamous cell hyperplasia

Question 5

Molluscum contagiosum

Answer 5

Acanthotic squamous mucosa; with directly underlying molluscum bodies (epidermal cells containing intra-cytoplasmic inclusion bodies)

Question 6

Herpes

Answer 6

MMM (molding, margination, multi-nucleation) and Cowdry type A inclusions

Question 7

Syphilis

Answer 7

Swelling and proliferation of endothelial cells + peri-vascular infiltrate of plasma cells and lymphs

Question 8

Condyloma accuminatum

Answer 8

Surface hyperkeratosis with acanthosis of underlying epithelium + koilocytisis

Question 9

Granuloma inguinale

Answer 9

1) massive granulation tissue response containing numerous plasma cells
2) diffuse infiltration of neutrophils
3) rare lymphocytes
4) large mononuclear cells containing Donovan bodies (large, bipolar intra-cytoplasmic, encapsulated rods)

Question 10

CMV

Answer 10

Cowdry type B inclusions

Question 11

Schistosoma

Answer 11

calcified ova in tissue sections

Endemic in Malawi

Question 12

Histoplasma capsulatum

Answer 12

Fungal, usually pulmonary infxn, but can be disseminated in immunocompromised pts

multiple, small, encapsulated organisms within histicytes

Endemic in Ohio & Mississippi River valleys

Question 13

Coccidioides immitus

Answer 13

Large, round, thick-walled spherules; containing hundreds to thousands of highly infectious endospores

Question 14

Cryptococcus neoformans

Answer 14

Ubiquitous fungus; worldwide distribution; natural habitat: soil

Round, budding yeast with mucinous capsule; stains with mucicarmine staining

Question 15

Blastomyces dermatiditis

Answer 15

Broad-based budding; seen on Gomori silver stain

Endemic to Ohio & Mississippi River valleys

Question 16

Merkel cell carcinoma

Answer 16

neuroendocrine neoplasm of the skin

Question 17

Aggressive angiomyxoma

Answer 17

Women in reproductive age

Locally aggressive, but usually not metastatic

Low to moderate cellularity; myxoid stroma; numerous medium-sized to large blood vessels; HGMA2 positive in 50%