Primary leiomyosarcoma of the breast: diagnosis, management and outcome. A report of a new case and review of literature

Primary leiomyosarcoma of the breast is very rare and represents a diagnostic challenge. Only 16 cases have been reported in the English language literature. We report another new case and have analysed reports of the previous cases aiming to present a simple evidence-based approach to the clinical, radiological and pathological diagnosis of this rare tumour. The average age of presentation is 56 years. All neoplasms have been limited to the breast at the time of diagnosis. The usual presentation is a slowly growing mass, but in the current case report the patient present with mastalgia. There is always a possibility of local recurrence or distant spread, which can occur many years after primary surgery. Leiomyosarcoma must be histologically distinguished from leiomyoma and the presence of >3 mitoses per 10 high-power fields is usually indicative of malignancy. Immunohistochemistry is helpful to confirm diagnosis. As this is a slow-growing malignant tumour with a propensity for local recurrence, total mastectomy is the treatment of choice. The tumour is not hormone-dependent and hormone manipulation is not a treatment option.