Endometrial carcinoma with argyrophil cells: a histochemical and immunohistochemical analysis.

Fourteen of fifty-three cases of endometrial carcinoma (26 per cent) contained varying, usually small numbers of argyrophil cells, as demonstrated by Grimelius silver nitrate staining of formalin-fixed paraffin-embedded sections. In eight cases the argyrophilia was present in the apical region of glandular cells (type 1 cells) or throughout the cytoplasm of glandular or squamous cells (type 2 cells). The distribution of argyrophilia in these cells closely paralleled that of mucin or glycogen, and pretreatment of the sections with disease resulted in a loss of argyrophilia in the glycogen-rich tumors. In six cases individual round, ovoid, and flask-shaped argyrophilic cells were present also within the glandular epithelium (type 3 cells). In all six cases, similarly distributed cells were positive immunohistochemically for serotonin. Immunohistochemical staining for a battery of polypeptide hormones (calcitonin, gastrin, somatostatin, adrenocorticotropin [ACTH], and neurotensin) revealed positive staining for ACTH in one of the six tumors that contained type 3 cells and positive staining for somatostatin in another. Ultrastructural examination of the ACTH- and serotonin-positive tumor disclosed cells with granules 80 nm in diameter. Types 1 and 2 argyrophil cells were found in small numbers in several specimens of normal proliferative and secretory endometrium, but type 3 argyrophil cells were not identified in these specimens. Although focal argyrophilia is a frequent feature of endometrial carcinomas (26 per cent), the presence of type 3 argyrophil cells containing hormones, as evidenced by the immunohistochemical demonstration of serotonin and occasionally polypeptide hormones, is much less common (11 per cent).