Splenic micronodular large B-cell lymphoma (SMLBCL)

Involves the splenic white pulp in a micronodular pattern but spares the red pulp.

T cells	CD3	positive
histiocytes	CD68	positive
B cells	CD20	positive
	CD79a	positive
	bcl-6	positive
	Oct-2	positive
	bcl-2	positive
	CD10	negative
	CD138	negative
	EBV-LMP-1	negative
	EBER	negative
	CD30	variable
	EMA	variable
follicle dendritic cells	CD21	absent
follicle dendritic cells	CD35	absent

Differential diagnosis:

granulomatous inflammation
classical Hodgkin's disease
nodular lymphocyte predominance Hodgkin's disease
follicular lymphoma
peripheral T-cell lymphoma

References:

Dogan A, Isaacson PG. Micronodular (T-cell/histiocyte rich) large B-cell lymphoma of the spleen: histology, immunophenotype and differential diagnosis. J Pathol 2001;193 (suppl):20^A.

Dogan A, Burke JS, Goteri G, et al. Micronodular T-cell/histiocyte-rich large B-cell lymphoma of the spleen: histology, immunophenotype, and differential diagnosis. Am J Surg Pathol 2003; 27:903-11