Secretory breast carcinoma: a clinicopathological and immunohistochemical study of 7 cases

Secretory breast carcinoma (SBC) is a rare distinct subtype of invasive breast cancer with good prognosis. Due to the limited reported SBC cases, our aim was to discuss the clinicopathological features of a series of SBC cases. We accepted 7 cases of SBC from the First Affiliated Hospital of China Medical University between 2011 and 2015. Seven respective tissue slides were stained with hematoxylin and eosin and performed immunohistochemistry with antibodies against ER, PR, HER-2 and Ki-67. The age of the patients (all women) ranged from 25 to 61 years (median age, 50). The tumor sizes ranged from 1.70 cm to 3.04 cm in diameter (median size, 2.0 cm). None had positive axillary lymph nodes. Histologically, most cases showed mixed microcystic, solid and tubular patterns. All tumor cells showed intracellular and extracellular secretory materials and mild to moderate dysplasia. Immunohistochemically, most cases were negative for ER, PR, and HER2 and had a low Ki-67 LI. The median follow-up period was 39 months, and they did not have recurrence after surgery. One patient was not available for follow-up. One patient developed recurrence and metastasis 18 months after the initial surgery and died within 42 months of the surgery. This case had mixed patterns, moderate nucleus atypia, a prominent nucleolus, and high Ki-67. We suggested that solid and nested invasive growth patterns, higher nucleus grade, and high Ki-67 LI may be related to poor prognosis. However, the number of cases was not enough and more studies need to be researched in the future.