
Malignant peripheral nerve sheath tumor (MPNST) is very unusual type of soft tissue sarcoma (STS) and occurs mostly in patients of neurofibromatosis. The occurrence of MPNST in breast tissue is particularly rare. Only 8 cases have been reported till date in absence of history of neurofibromatosis. We are reporting such case in a 30 years old male who presented with hard and painless breast lump for 3 months. Patient was treated with wide local excision and surgical specimen was submitted for histopathological examination. Microscopic examination revealed a malignant spindle cell tumor of low grade. Immunohistochemistry (IHC) was performed which showed positivity of vimentin and negative for LCA (leukocyte common antigen), CD99, desmin, Bcl-2, S-100. Final diagnosis MPNST was put on the basis of morphological appearance and IHC. Patient was treated with postoperative radiotherapy in dose of 50 Gy in 25 fractions in view of unknown margin status. At present patient is on regular follow up.