Primary jejunal malignant mixed tumor in a patient with von Recklinghausen neurofibromatosis.

A rare case of primary jejunal malignant mixed tumor arising in a 49-64-old Japanese male with von Recklinghausen's disease is reported. The patient, who had a past history of partial gastrectomy due to duodenal ulcer, was admitted with a complaint of epigastric pain. Upper gastrointestinal examinations showed a huge polypoid tumor located in the efferent loop of the gastrojejunostomy site. Because the tumor was strongly suggestive of leiomyosarcoma on histological examination of biopsy specimens, laparotomy was performed. The resected tumor measuring 10 X 7 X 7 cm was composed of adenocarcinoma admixed with various sarcomatous components, including rhabdomyosarcoma, osteosarcoma, and other sarcomas. Immunohistochemical analysis also supported this diagnosis. The features of this tumor closely resembled malignant mixed mullerian tumor of heterologous type that develops in female genital organs. It is well known that patients with von Recklinghausen neurofibromatosis have an increased incidence of mesenchymal tumors and malignant neoplasias, and therefore, it seems that there is a possible relationship between the histogenesis of this peculiar tumor and the genetic abnormality in this patient.