Pleura and peritoneum

Question 1

keratin granulomas

Answer 1

ruptured dermoid cyst

amniotic fluid peritonitis

endometrioid adenoca with sq differentiation

cervical SCC

Question 2

inflammatory fibrosclerosing lesions of peritoneum

Answer 2

sclerosing peritonitis (some are IgG4 disease)

infection

drugs

peritoneal dialysis

fibroma/thecoma

malignancy (mesothelioma, carcinoma, lymphoma)

Question 3

spindle cell lesions

Answer 3

common:

fibrosing (chronic) pleuritis

sarcomatoid mesothelioma

spindle cell carcinoma

SFT

IMT (ALK+)

less common:

calcifying fibrous pseudotumur (ALK-)

synovial sarcoma

fibromatosis

Question 4

epithelioid lesions

Answer 4

reactive mesothelial hyperplasia

well diff papillary mesothelioma

epithelioid mesothelioma

lung adenoca

mullerianosis

serous ca

Question 5

biphasic tumours

Answer 5

mesothelioma

carcinosarcoma

synovial sarcoma

Wilms tumour (kids)

Question 6

reactive mesothelial hyperplasia vs mesothelioma

Answer 6

mesothelioma: necrosis, more atypia, GLUT1+, desmin-, 9p deletion

Question 7

mesothelioma vs adenoca

Answer 7

meso: calretinin (needs nuclear staining), CK5/6, WT1 (also in ov serous), D240, membranous EMA, p16 deletion (FISH)
adeno: MOC31, BerEP4, B72.3, TTF1, NapsinA, cytoplasmic EMA

(both are CK7+ CK20-)