[Leiomyoblastoma of the digestive tract].

Five cases of leiomyoblastoma of the stomach and one located in the small intestine have been reported. Two of the gastric tumours metastasized. The characteristic feature of leiomyoblastoma is vacuolation of the cytoplasm of polygonal tumour cells, with regularly demonstrable transitions into smooth muscle cells. The size of the neoplasm and the presence of mitoses do not represent sufficiently reliable features permitting to recognize the biological behaviour of the tumour. Cellular and nuclear pleomorphism seemed to be a much more reliable index of malignancy in the two cases of ourselves.