Postirradiation sarcoma (malignant fibrous histiocytoma) in the inguinal region.

A female patient who died of apparent postirradiation sarcoma at the age of 39 was reported. Following a traffic accident, she developed squamous cell carcinoma at the injured right heel 20 years later, and also metastasis to both inguinal and popliteal lymph nodes. During the period from September 1966 to May 1968, she had received Co60 irradiation to the right inguinal and para-aortic areas, 9,600 and 6,600 Roentgen, respectively. Ten years later, she manifested a huge tumor in the inguinal region which extended further to the retroperitoneum; light and electron microscopic examinations proved to be a malignant fibrous histiocytoma. She died of massive pulmonary metastasis two years later. Histological differentiation of the tumor and relationship between irradiation and sarcoma induction were briefly discussed, and the necessity of reevalution of soft part sarcomas was emphasized.