Rare case of primary leiomyosarcoma of the breast treated with wide local excision and planned cosmetic breast reduction surgery.

Primary leiomyosarcoma of the breast is an extremely rare neoplasm accounting for less than 0.0006% of all breast malignancies, with fewer than 80 cases reported in the literature to date. Here, we present a case of leiomyosarcoma of the breast in a 61-year-old woman without traditional risk factors. This case was treated with lumpectomy requiring wide margins due to the high rate of local recurrence. A planned breast reduction surgery was deemed adequate postlumpectomy therapy to prevent cancer recurrence, negating the need for chemotherapy or radiation therapy. To our knowledge, this is the first case in which cosmetic breast reduction surgery will be used as postlumpectomy cancer recurrence risk mitigation for primary leiomyosarcoma of the breast. Patients with this malignancy have a relatively poor prognosis compared with other breast cancer types, with a 5-year disease-free survival of 33%-52%. As such, frequent follow-up and monitoring for postresection recurrence is essential.