Accessory breast cancer in the inframammary region: a case report and review of the literature

Abstract

Background Although a few cases of accessory breast cancer (ABC) have been reported, most were in the axillary region. We encountered an extremely rare case of ABC in the inframammary region (IMR). Case presentation The patient was a 68-year-old postmenopausal woman who had noticed a congenital accessory nipple in her left IMR with slight, occasional discharge 20 years ago. Recently, she noticed a mass under the accessory nipple and visited a nearby clinic; fine-needle aspiration cytology of the mass revealed that it was malignant. She presented to our department 2 weeks after she had noticed the mass. Physical and imaging examinations showed an irregular tumor mass 1.7 × 1.4 × 1.0 cm in size connected to the accessory nipple beneath the left normal breast. Neither distant metastasis nor lymph node swelling was observed. Ultrasound-guided core needle biopsy revealed the mass to be invasive ductal carcinoma. We diagnosed her tumor as ABC in the left IMR; cT1cN0M0: stage IA. Curative wide resection with sentinel node biopsy was performed. Intraoperative evaluation of the frozen section revealed a hot and green ipsilateral axillary lymph node that was free from carcinoma; therefore, nodal dissection was avoided. Histopathological examination including immunochemical staining revealed that the tumor was invasive ductal carcinoma arising from the accessory breast tissue, scirrhous type, 1.7 × 1.4 × 1.0 cm in size, with a solid intraductal component. There was no lymphovascular infiltration, and the surgical margin was 1.5 cm or more. The tumor was estrogen and progesterone receptor-positive, Her2/neu-negative, and had a Ki-67 labeling index of 20%. There was no involvement of the three hot and/or green nodes. The final classification was pT1cN0(sn)M0: stage IA. Letrozole 2.5 mg/day will be administered for 5 years as adjuvant hormonal therapy. Conclusions A cutaneous and/or subcutaneous lesion except for proper breast tissue on the milk line, or mammary ridge from axilla to groin may be an accessory breast tissue. Its serial abnormalities must be worried malignant potential to ductal carcinoma which needs some imaging and pathological examinations for definitive diagnosis and appropriate treatment according to the usual orthotopic breast cancer without delay.

Male Accessory Breast Cancer Successfully Treated With Single-Agent Trastuzumab: A Case Report

“…Accessory breasts are observed in 2% to 6% of the general population, and these tissues may present in various positions along the milk line but most frequently in the axillary region. An accessory breast carcinoma is a form of breast cancer occurring in the axilla or inguinal region, where there are abundant lymph nodes and capillaries (Bi et al, 2015; Eguchi et al, 2021; Gutermuth et al, 2006). Male accessory breast cancer is rare tumor.…”

Accessory breast cancer: A case report and literature review of ultrasonographic findings

“…There has been no systematic analysis of ultrasonographic findings in ABCs, and we have summarized the findings of previous reports in a table (Figure 1f). [1][2][3][4][5] Two types of ultrasonographic findings surrounded by heterogeneous hyperechoic areas (indicating mammary tissue) have been reported: one is a lobulated hypoechoic mass and the other is an irregular hypoechoic mass. When these findings are observed, ABC should be considered in the differential diagnosis.…”