Clinical and pathologic considerations in a case of inflammatory myofibroblastic tumor of the spleen.

Inflammatory myofibroblastic tumors, also called inflammatory pseudotumors, are rare pseudosarcomatous proliferations. Their behavior is generally not aggressive, but in most instances they can simulate malignant neoplasms, from which they are impossible to distinguish before excision. One case of myofibroblastic tumor of the spleen in a 5-year-old boy is described: the patient was treated with a partial splenectomy, which was found to be the best approach for diagnosis and treatment. The purpose of this report is to call attention to this entity with peculiar histologic and immunohistochemical characteristics, which has to be included in the differential diagnosis of splenic lesions and may be excised by a nonaggressive procedure.