Adenomatoid tumours: An immunohistochemical and ultrastructural appraisal of their htstogenests

Abstract

The histogenesis of adenomatoid tumour has continued to provoke debate since Golden and Ash suggested the term in 1945 for all characteristic benign neoplasm typically found in the uterus, fallopian tube or epidiymis. Hndothelial, epithelial, mesonephric, müllerin and mesothelia histogenesis have been suggested. The balance of evidence suggests mesothclial derivation, but two rcecent studies point to endothelial origin for at least some of these tumours, Twenty-two histologically typical adenomatoid tumours were studied by electron microscopy, mucin histochemistry and immunohistochemistry. Ultrastructurally, all cases showed vacuolated cells bearing long bushy microvilli and the features were not those of endothelial cells. Glandular spaces contained acid mucopolyscharide consistent with hyaluronic acid. Immunohistochemical double labelling techniques showed the cells lining such spaces to contain cytokeratin in the absence of factor VIII related antigen and receptors for Ulex europapeus I leetin which were expressed in the endothelium of tumour blood vessels. The evidence points !o mesothelial histogenesis in all cases examined.