title: Malignant peripheral nerve sheath tumor of the breast: case report.
abstract: BACKGROUND
  Malignant peripheral nerve sheath tumor is a rare soft tissue sarcoma of ectomesenchymal origin. It is the malignant counterpart of benign soft tissue tumors like neurofibromas and schwannomas and may often follow them. Common sites include deeper soft tissues, usually in the proximity of a nerve trunk. Breast is an extremely rare location of this lesion and presentation as a breast lump in the absence of pain or previous benign neural tumor is even rarer.
  
  
  METHODS
  A 38-year-old female presented with complaints of painless, hard breast lump for three months which was clinically suspected to be a ductal carcinoma with inconclusive fine needle aspiration cytology. Histopathology revealed a malignant spindle cell tumor which was confirmed to be malignant peripheral nerve sheath tumor on the basis of immunopositivity for vimentin, neurone specific enolase and S-100.
  
  
  CONCLUSIONS
  To the best of our knowledge only six such case reports have been published in literature. The differential diagnosis of malignant peripheral nerve sheath tumor should be considered by the clinician as well as the pathologists in the work-up of a breast neoplasm as treatment and prognosis of this rare malignancy is different.
authors.affiliation: Department of Pathology, Maulana Azad Medical College and associated Lok Nayak Hospital, Bahadur Shah Zafar Marg, New Delhi 110002, India. kajaldhingra@yahoo.com
authors.forename: Kajal Kiran
authors.initials: KK
authors.lastname: Dhingra
authors.forename: Shramana
authors.initials: S
authors.lastname: Mandal
authors.forename: Somak
authors.initials: S
authors.lastname: Roy
authors.forename: Nita
authors.initials: N
authors.lastname: Khurana
mesh_terms: D000328:Adult; D014408:Biomarkers, Tumor / Q000378:metabolism; D044963:Biopsy, Fine-Needle; D001943:Breast Neoplasms / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D018317:Nerve Sheath Neoplasms / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D010524:Peripheral Nervous System Neoplasms / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D014746:Vimentin / Q000378:metabolism
chemical_list: D014408:Biomarkers, Tumor; D014746:Vimentin