Mammary carcinoma with argyrophil cells

In a series of 253 cases of carcinoma of the breast, nonargentaffin, argyrophil cells were seen among the tumor cells in 27 cases (10.7%). An electron microscopic examination in one such case revealed dense cored secretory granules surrounded by a limiting membrane within the cytoplasm of the argyrophil tumor cells. Tumors with argyrophil cells, particularly when these cells were abundant, histologically showed a uniform appearance of relatively small constituent cells with oval or round nuclei of a regular size, forming solid alveolar nests or sheets. In one of these tumors, a delicate vascular stroma separated the sheets of tumor cells to form a ribbonlike pattern, simulating the feature of a carcinoid tumor. This tumor, however, is preferably interpreted at present as a mammary carcinoma with features of a carcinoid tumor, because of an incomplete characterization of argyrophil granules in the tumor cells. Other tumors with argyrophil cells were examples basically of ordinarily featured invasive ductal carcinoma. In a search for the origin of these cells, 99 breasts with various noncancerous lesions were examined; however, these argyrophil cells were never detected in any component of these mammary tissues.