Adenomatoid tumour of the epididymis: histochemical and ultrastructural study of 2 cases.

Two cases of adenomatoid tumour of the epididymis are described. Both the histochemical and ultrastructural studied support the concept that it is of mesothelial origin. The histochemical study showed the presence of acid mucopolysaccharides in the lumen of the tubular structures. The epithelial cells presented numerous microvilli in the free surface, junction complexes, wide intercellular channels and a well-developed Golgi complex. Abundant bundles of microfilaments and intracellular spaces were observed in the cytoplasm. Lymphocytes and histiocytes were identified both in the tubular lumen and between the epithelial cells. The stroma of the tumour was made up of dense connective tissue with abundant bundles of elastic fibres. The presence of intracytoplasmic spaces in the epithelial cells and elastic fibres in the stroma had not been previously observed in this tumour.