The so-called "carcinoid" tumors of the breast.

The so-called "carcinoid" tumors of the breast are at present a difficult entity to define. Two histopathological features are used to recognize such tumors: argyrophilia and ultrastructural dense-core granules. Eight cases of "carcinoid" tumor of the breast, observed over a 5-year period, with 3.6% incidence over the total of breast cancers recorded during the same period, are reported. All patients were females with a mean age of 55.2 years. Argyrophilia was found in all tumors and dense-core granules were observed in five studied ultrastructurally. No patient had nodal or distant metastases and no carcinoid syndrome was observed. A modified radical mastectomy was performed for tumors over 2.5 cm; in case of smaller tumors the surgical treatment was quadrantectomy with axillary dissection. All patients are alive and disease-free but follow-up is short. As the so-called "carcinoid" tumors of the breast have been only recently identified, additional morphological, immunohistochemical and clinical data are required for a full understanding of their significance.