engleski

Neuroendocrine cancer of the breast: a report of 11 cases

Neuroendocrine cancer (NC) of the breast is rare, usually showing alveolar structures or solid sheets of cells with a tendency to produce peripheral palisading. The expression of neuroendocrine markers chromogranin and/or synaptophysin in more than 50% of the cell population confi rms neuroendocrine diff erentiation. Depending upon the cell types, grade and degree of diff erentiation, NC has been categorized into the following subtypes: solid, small cell and large cell NC. All 11 patients were aged from 48 to 86 (median 57) years. The tumor size median was 17 mm (10-48 mm) in diameter. Eight tumors were classifi ed as solid, two as small cell and one as large cell type. Immunohistochemical examination was carried out using the following antibodies: chromogranin A, synaptophysin, estrogen receptor (ER), progesterone receptor (PR), androgen receptor (AR), human epidermal growth factor receptor-2 (HER-2) and Ki67. Positive reactivity for chromogranin A (8/11) and synaptophysin (11/11) confi rmed neuroendocrine differentiation in 11 cases of breast cancer. Immunohistochemically, the tumors expressed ER (11/11), PR (8/11) and AR (10/11), while HER-2 was negative in all cases. Median value for Ki-67 was 18% (range 7%-55%) and for the number of mitoses 4 (range 3-31). In one- way analysis of variance, histologic grade was infl uenced by the number of mitoses (P=0.0096) and tumor size (P=0.0035). Axillary lymph nodes were positive in two patients (2/11). Disease recurrence with distant metastases occurred, after 20 months, only in the patient with large cell subtype. All other patients were free of disease at the time of writing. Median followup was 20.5 (range 11-45) months. NC of the breast frequently expresses ER, PR and AR, while HER-2 is negative. Histologic subtype, grade and size of tumor are very important prognostic factors. More cases and longer follow-up periods are required to determine the behavior of these tumors.

neuroendocrine differentiation ; breast cancer

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