Apocrine breast carcinoma as an extremely rare breast cancer subtype – histopathological characteristics

Apocrine carcinoma (AC) is a distinctive and rare type of malignancy, counted for 0.3–4% of all breast cancer cases. It does not have a particular clinical or radiological features, although it is characterized by the apocrine morphology, estrogen receptor-negative and androgen receptor-positive profile. In the present study, among 1122 patients with breast cancer only 5 of them were diagnosed with apocrine carcinoma (0.4%). All patients were above 50 years old (51–63, mean: 57). Tumor size varied from 1.4 cm to 3.8 cm with a mean size of 2.4 cm, while mean size of all 1122 studied cases counted for 1.9 cm. Two tumors were classified as high-grade (G3), 2 as G2, and 1 as G1. Four tumors out of 5 did not affect lymph nodes (pN0 stage), whereas 1 was classified as pN2 with 9/19 regional lymph nodes affected. This observation was consistent with the whole studied group, in which pN0 stage made up the largest percentage. Presented results suggest that AC is less frequent in premenopausal patients. AC tends to present as invasive malignancy without nodal involvement and is usually characterized by relatively less aggressive biological behavior compared to other histological types of breast cancer. Due to the fact that AC is definitely a rare type of breast cancer, modern medicine has still limited treatment options to offer. Further research needs to be conducted in order to develop target therapies for this carcinoma