Prostate

Question 1

malignant mimics of benign

Answer 1

atrophic ca: infiltrative, macronucleoli

foamy gland ca: pink secretions

pseudohyperplastic ca: large closely packed glands with papillary infolding

Question 2

benign mimics of malignancy

Answer 2

normal structures: Cowper glands, seminal vesicle (lipofuscin granules), colonic mucosa

hyperplasia: basal cell, mesonephric

atrophy (small glands, basophilic, no atypia)

adenosis (lobular, focal basal cells)

inflammation: granuloma, xanthogranulomatous, malakoplakia

radiation

nephrogenic adenoma

Question 3

HG PIN DDX

Answer 3

clear cell cribriform hyperplasia: clear cytoplasm, benign nuclei, prominent basal cells

basal cell hyperplasia: crowded glands, two cell populations, HMWCK/p63+

normal central zone: pink cytoplasm, prominent basal cells, parallel nuclear streaming

Question 4

granulomas

Answer 4

postoperative: fibrinoid necrosis

BCG
infection (TB, fungus, schistosoma)

non-specific granulomatous prostatitis: lobular inflammation around ducts, foamy histiocytes

allergic granulomatous prostatitis (rare!): fibrinoid necrosis, eosinophils++

Question 5

pathognomonic features of prostate ca (3)

Answer 5

perineural invasion

mucinous fibroplasia (collagenous micronodules)

glomerulations

Question 6

spindle cell lesions

Answer 6

carcinoma

IMT

leiomyoma/sarcoma

rhabdomyosarcoma (kids)

STUMP

prostatic stromal sarcoma

Question 7

intraductal adenocarcinoma (Stanford criteria)

Answer 7

smooth borders

basal cells at periphery (may be patchy)

solid or cribriform

variation in cell size up to 6x

+/- comedonecrosis

Question 8

intraductal carcinoma DDX

Answer 8

HG PIN: no pleomorphism/comedonecrosis

acinar adenocarcinoma: no basal cells, ragged

ductal adenocarcinoma: tall cells, slit-like cribriform lumens