Elastogenesis in adenomatoid tumor: histochemical and ultrastructural observations.

An adenomatoid tumor from the round ligament of a 50-year-old woman was studied by light and electron microscopy. Ultrastructurally the tumor was remarkably similar to normal as well as neoplastic mesothelium, thus lending further support to the concept of a mesothelial origin of adenomatoid tumors. Comparative histochemical and ultrastructural studies revealed presence of acid mucopolysaccharides mainly along the luminal borders of the tumor cells, thus indicating likely production of this material by the tumor cells as opposed to the stromal cells. The stroma was rich in elastic fibers and there was evidence of active elastogenesis. This paper represents the first unequivocal demonstration of elastogenesis in an adenomatoid tumor.