Splenic B-cell lymphoma / leukaemia, unclassifiable

Epidemiology and Etiology:

Common sites:

Gross features:

Histologic features:

• Splenic diffuse red pulp small B-cell lymphoma (provisional entity)
• Hairy cell leukemia-variant (HCL-v) (provisional entity)
• Others
• Diffuse infiltration of red pulp, with atretic or absent white pulp follicles

Immunophenotype:

Marker:	Sensitivity:	Specificity:
(HCL-v):
Similar markers to HCL except:
CD25 (neg)	characteristically
Annexin A1 (neg)	characteristically
TRAP-IHC (neg)	characteristically
CD123 (neg)	characteristically
HC2 (neg)	characteristically

Molecular features:

Other features:

References:

• Swerdlow et al. WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues (2008)