Primary nonlymphoreticular malignant neoplasms of the spleen.

Primary sarcomas of the spleen are exceedingly uncommon neoplasms, approximately 90 substantiated cases having been reported. We report on six cases of primary splenic angiosarcoma and three cases of primary malignant fibrous histiocytoma of the spleen which have been seen at the Mayo Clinic during the last 51 years. In one of the cases of splenic angiosarcoma, the lesion was manifested by spontaneous rupture and hemoperitoneum; interestingly, two cases of splenic malignant fibrous histiocytoma were of the inflammatory type and showed corresponding clinical features of a systemic nature. Five patients with angiosarcoma of the spleen died of metastatic tumor within 3 years after diagnosis; one patient with splenic malignant fibrous histiocytoma is alive with metastasis 11/2 years after splenectomy. One case of splenic angiosarcoma and two of malignant fibrous histiocytoma of the spleen have been diagnosed only recently. All three patients are alive and currently tumor-free, from 3 to 7 months after diagnosis.