Ultrastructure of gastric leiomyosarcoma.

Samples of gastric leiomyosarcomas from two male patients (69 years and 57 years of age) were studied by electron microscopy. The tumour cells contained abundant 50--90 A thick microfilaments and microtubules. Another cell type, regarded as immature leiomyosarcoma cell, contained numerous profiles of granular endoplasmic reticulum, free ribosomes and a well developed Golgi apparatus. There were intercellular junctions of zonula adherens-type between adjacent tumour cells. It was concluded that electron microscopy offers a valuable aid in the diagnosis of gastric neoplasms of smooth muscle origin.