Neoplastic nature of argyrophil cells in urachal adenocarcinoma.

The histological, histochemical and electron microscopic features of the metastatic tumors of an urachal adenocarcinoma, were presented. Metastatic tumor nodules in the lungs and brain as well as the primary tumor showed tubular adenocarcinoma containing many argyrophil cells. Immunoperoxidase examination revealed three kind of endocrine cells which contained different endocrine hormones. Electron microscopic examination showed small, round endocrine granules in the endocrine cells and desmosome-like complexes in between these cells and the adjacent glandular neoplastic cells. These findings suggested that the endocrine cells were neoplastic in nature and originated from primitive neoplastic cells as well as glandular neoplastic cells.