Fibroadenoma in Axillary Supernumerary Breast in a 17-Year-Old Girl: Case Report.

BACKGROUND

Supernumerary breast or polymastia is a well documented anomaly of the breast, and commonly presents along the embryonic milk line extending between the axilla and groin. However, cases of polymastia have been recorded in the face, vulva, and perineum. The clinical significance of these anomalies include their susceptibility to inflammatory and malignant changes, and their association with other congenital anomalies of the urinary and cardiovascular systems.

CASE

In this article we report a case of fibroadenoma that developed in the supernumerary breast of the right axilla in a 17-year-old girl. It is uncommon to find such palpable masses in young patients. Clinical and sonographic examination of both breasts revealed no abnormalities and no lymph nodes were detected in the axillae or the neck. No associated urologic or cardiovascular abnormalities were found, and the histopathological examination of the excisional biopsy samples showed a well-defined, capsulated intracanalicular type of fibroadenoma similar to that of eutopic mammary tissue.

SUMMARY AND CONCLUSION

In this report, we describe a rare case of fibroadenoma in an accessory breast in a young woman. There are a fewer than 40 reports in the world about this subject, of which differential diagnoses include: cancer in axillary supernumerary breast, hidradenitis, axillary lymphadenomegaly, lipomas, anexial cutaneous neoplasia, cysts, and phylloides tumor. The combination of clinical examination, ultrasound, and cytology leads to adequate treatment, especially surgical. The diagnosis could be confused because of findings from cytology. In this case, because of the clinical and sonographic findings and multiple differential diagnosis, only the histopathological study was used to confirm the diagnosis. Despite its high sensitivity, cytology has low specificity and could create false positive results. However, atypical lesions can be seen in fibroadenomas, especially in younger patients, pregnant patients, and in patients who use hormonal contraception. Although there are a few reports, our case report is similar to current medical registers and, after surgical treatment, our patient had an excellent prognosis.