ABSTRACT
Spleen has a tripartite role: acting as a sieve for the circulatory system, phagocytosis, and storing blood cell elements for possible future use. The spleen is composed of white pulp, red pulp, cords, and sinuses. The white pulp consists of B cells and periarteriolar T-cell lymphoid sheaths. The follicles, similar to the lymph node, can be divided into primary and secondary follicles with similar morphologic characteristics. The follicles are often colonized by neoplastic B cells, which eventually lead to follicle regression. Presence of residual follicles and atypical expanded marginal zone with monocytoid B cells gives the impression of the biphasic pattern under low magnification. The spleen shows diffuse involvement of the red pulp, with both cord and sinusoid infiltration and characteristic intra-sinusoidal aggregates. Mantle Cell Lymphoma involving the spleen shows usually the involvement of the white pulp, but prominent diffuse involvement with massive splenomegaly and leukemic blood involvement with “prolymphocytoid” morphology have been reported.
