Surgery for fibroadenoma arising from axillary accessory breast.

[BACKGROUND] Patients with fibroadenomas in axillary accessory breasts (AABs) have a palpable mass, cyclic axillary pain, and aesthetic concerns that must be addressed. We compared the baseline patient characteristics, AAB characteristics, and surgical outcomes of patients with AABs with and without fibroadenomas undergoing surgical excision. We also monitored the patients for recurrence of axillary fibroadenomas.

[METHODS] This retrospective study involved 2310 women who underwent AAB excision from 2014 to 2019. Patients with and without a palpable fibroadenoma were divided into a fibroadenoma group and non-fibroadenoma group, respectively. All patients underwent complete excision of accessory mammary gland (AMG) tissue, including fibroadenomas in the AABs. We removed the fibroadenoma and the AMG tissue with a minimal axillary incision.

[RESULTS] Thirty-nine patients had a palpable fibroadenoma in the AAB, and all patients in the fibroadenoma group had cyclic axillary pain and a palpable axillary mass. There were no significant differences in the patients' age, weight of the AMG tissue, liposuction volume, or fibroadenoma laterality between the two groups. The body mass index in the fibroadenoma group was lower than that in the non-fibroadenoma group (19.9 vs. 22.3 kg/m, respectively; P < 0.000). Concurrent fibroadenoma excision in a normal breast on the chest was performed more often in the fibroadenoma group than in the non-fibroadenoma group (35.9% (14/39) vs. 4.1% (92/2271), respectively; P < 0.000). The mean fibroadenoma size was 2.1 cm (range, 1.1-9.1 cm). All patients were satisfied with the degree of postoperative pain relief, disappearance of palpable lesions, and cosmetic improvement. No patients developed fibroadenoma recurrence.

[CONCLUSIONS] Complete excision of the AMG tissue and fibroadenoma is appropriate in patients with an AAB with a fibroadenoma. Surgeons should also consider the high incidence of concurrent fibroadenomas in the normal breasts on the chest.