Hepatic tumors of long duration with eventual metastases. Two cases of leiomyosarcomatosis possibly arising from hamartomas of liver.

The cases of two patients who had hepatic tumors of long duration interpreted as hamartomas in whom, after many years, widespread metastases of malignant smooth muscle cells developed in a pattern of "carcinomatous lymphangitis" in the lungs are described. In one of the cases calcification of the hepatic nodules was prominent. The smooth muscle origin of the malignant cells was established only on electron microscopic examination. These cases appear similar to others variously reported as mixed tumors, hepatic cell carcinomas, and mesotheliomas.