Imaging Findings of Breast Metastasis from Malignant Peripheral Nerve Sheath Tumor of Mediastinum: A Case Report.

Malignant peripheral nerve sheath tumor (MPNST), a rare soft-tissue sarcoma, is most commonly located in the trunk, extremities, and head and neck, but rare in the breast. We report a metastatic breast MPNST in a 27-year-old woman with neurofibromatosis type 1 (NF-1). Chest computed tomography revealed a well-defined, oval, mildly enhancing nodule in the right breast. US revealed a circumscribed, oval, heterogeneous echoic mass with vascularity and intermediate elasticity in the right upper outer breast. The breast mass was excised and diagnosed as MPNST on histopathology evaluation. Although rare, it should be included in the differential diagnosis of breast mass in NF-1 patient.