A case of splenic lymphoma with marked diffuse nodular fibrosis and calcification, complicated with severe autoimmune hemolytic anemia.

A splenic lymphoma, possibly of a splenic marginal zone lymphoma, marked by small nodular splenic calcified fibrosis and complicated by intractable autoimmune hemolytic anemia, was studied by immunohistochemical, molecular genetic, and ultrastructural analyses. The patient was a 57-year-old Japanese man who had moderate splenomegaly, and who had undergone splenectomy for improvement of severe autoimmune hemolytic anemia and to rule out malignancy in the spleen. In the resected spleen, proliferative atypical lymphoid cells were observed both in the red and white pulp with diminished germinal centers and irregularly widened marginal zones with peculiar dimorphic pattern. Ultrastructural study revealed no hairy cells or villous lymphocytes. Diffuse nodular hyalinous fibrosis surrounding the small arterioles in the white pulp overlapped with frequent calcification was a unique histologic feature in this case. Degenerative connective tissue, extracellular matrix, or collagen fibers surrounding the arterial sheath in the white pulp caused by some immunological abnormalities associated with this splenic lymphoma could be assumed to be the predisposing factor for this excessive fibrosis and dystrophic calcification in the spleen.