Inflammatory pseudotumor of the spleen: a clinicopathology study of three cases.

The clinical and pathologic findings of three cases of splenic inflammatory pseudotumor are described, and differential diagnostic features are discussed. This benign lesion is extremely rare, only four having been previously reported. Inflammatory pseudotumors often pose diagnostic difficulties because they form infiltrative masses which have clinical and gross pathologic features that suggest malignancy. Although these lesions are usually easily recognizable microscopically as benign processes, the admixed component of lymphoid and other hematopoietic cells may sometimes raise the question of a lymphoreticular malignancy, requiring immunohistologic studies for resolution in some cases. Alternatively, pseudotumors may be mistaken for infectious granulomatous processes, sarcoidosis, or hamartomas.