Breast cancer with splenic metastasis in a male patient

Radiol Bras. 2016 Set/Out;49(5):340–346 344 http://dx.doi.org/10.1590/0100-3984.2014.0136 Leiomyoma is a benign tumor composed of smooth muscle tissue and is considered one of the most common mesenchymal neoplasms in the gastrointestinal tract and uterus. Leiomyoma of the breast originates from the stroma of the gland and is extremely rare. Mammography and ultrasound studies are commonly used as screening tools. However, the histopathological evaluation is the definitive diagnostic method. The differential diagnoses include carcinoma, sarcoma, benign tumors and tumor-like conditions. The treatment consists of surgical excision of the lesion, and recurrence is unusual. Smooth muscle tumors are uncommon, especially in the mammary gland. Such tumors account for less than 1% of all breast neoplasms. Deep parenchymal lesions are extremely rare and seem to affect only women. Leiomyomas affect women from 30 to 60 years of age, the mean age being 47.6 years. They often occur near the nipple-areola complex, because of the abundance of smooth muscle cells in that area. Smooth muscle is a component that can be present in other lesions, such as fibroadenomas and hamartomas. Leiomyomas located in the parenchyma (as in the case reported here) are circumscribed and 1.0–14.0 cm in diameter. There are no radiological criteria for making the diagnosis with certainty, histopathological and immunohistochemical studies of the lesion being necessary in order to make the definitive diagnosis. The histopathological differential diagnosis is established with fibroadenoma, phyllodes tumor, adenomyoepithelioma, and leiomyosarcoma of the breast. On histopathology, leiomyosarcoma of the breast shows pronounced cell atypia, atypical mitosis, vascular invasion, and necrosis. Although patients are typically asymptomatic, there can be pruritus, increased breast volume, pain, and hardening of the nipple or nodule.