Spleen

Question 1

infections

Answer 1

EBV: white pulp follicular hyperplasia, red pulp atypical immunoblasts

CMV: necrosis, neutrophils

Question 2

clear cells

Answer 2

marginal zone lymphoma: white pulp expansion

hairy cell leukaemia: red pulp expansion, annexinA1+

hairy cell leukaemia variant: annexinA1- (and no BRAF mut)

T cell lymphoma/leukaemia

mastocytoma: fibrosis, eosinophils

Question 3

Littoral cell angioma vs splenic hamartoma

Answer 3

littoral cell angioma: CD68+, CD8-

splenic hamartoma: CD68-, CD8+

Question 4

inflammatory pseudotumour (features)

Answer 4

mix of fibroblasts, myofibroblasts (SMA+) and histiocytes (CD68+)

ALK- (ie different to IMT)

mixed inflammatory background

Question 5

non neoplastic, think of…

Answer 5

chronic congestion

extramedullary haematopoiesis

infarct

Question 6

miliary small white nodules

Answer 6

follicular lymphoma: cleaved cells

CLL/SLL

LPL

mantle cell lymphoma: monotonous cells

marginal zone lymphoma (splenic, nodal and extranodal): clear cells, circulating villous cells on blood film in splenic MZL

(rarely) Hodgkins

non-neo DDX: miliary TB, mycobacterial spindle cell pseudotumour, amyloidosis

Question 7

Answer 7

Mastocytosis: clear cells in marginal zone, sclerosis

Question 8

Answer 8

Hairy cell leukaemia: diffuse clear cells in red pulp

Question 9

Answer 9

Littoral cell angioma: tortuous and dilated vessels, pseudopapillary, cd31/cd68+ (cd34-)

Question 10

Answer 10

Splenic hamartoma: well circumscribed, ‘jumbled’ red pulp (do reticulin)

Question 11

solitary or clustered small nodules

Answer 11

Hodgkin lymphoma (classical or NLP)

non-neo DDX: lymphoid hyperplasia

Question 12

solitary or multiple large fleshy nodules

Answer 12

large cell lymphomas: DLBCL, G3 follicular lymphoma, T cell lymphoma, Hodgkins (sometimes)

metastatic carcinoma

non-neo DDX: inflamm pseudotumour, hamartoma, bacillary angiomatosis

Question 13

expanded red pulp (beefy red, minimal white pulp)

Answer 13

leukaemia, except CLL

hepatosplenic T cell lymphoma

DLBCL and peripheral TCL (rare)

LCH

myelofibrosis

mastocytosis

non-neo DDX: infectious mono, hemophagocytic syndrome, congestive splenomegaly, haemolytic anaemia, storage disease, amyloidosis

Question 14

granulomas

Answer 14

infection

sarcoid

chronic uraemia

lymphoma

inflammatory pseudotumour-like FDC sarcoma

Question 15

Answer 15

Mycobacterial spindle cell pseudotumour (zn+)

Question 16

cysts

Answer 16

pseudocyst (most common)

epithelial: squamous +/- keratin or mucin

mesothelial

parasitic

Question 17

vascular tumours

Answer 17

haemangioma (incl littoral cell)

lymphangioma

peliosis (2o steroids/wasting): haphazard vessels, no mass

haemangioendothelioma

angiosarcoma

Kaposi sarcoma

bacillary angiomatosis: Bartonella on Warthin-Starry

sclerosing angiomatoid nodular transformation (SANT): vascular nodules in sclerotic stroma