[2 cases of alveolar sarcoma. Study by electron microscopy and cytoenzymology].

Study by electron microscopy and light cytoenzymology of two cases of alveolar sarcoma of the thigh occurring in young men indicated it to be an active tumour with an apparently functional organoid arrangement, characterised by an abundance of capillary vessels. The secretory nature of the cell elements was suggested by the marked development of smooth and granular reticular systems. The morphological result of this secretory activity was constituted by vesicular bodies with dense contents, surrounded by a membrane and sometimes containing periodic paracrystalline structures. This intravacuolar crystalline organisation goes hand in hand with an increase in acid phosphatase activity suggesting possible crinophagia. Amongst the different hypotheses advanced in the past, the morphological appearances seen here would most likely correspond with the endocrine nature of this tumour.