title: Malignant peripheral nerve sheath tumor with extensive osteosarcomatous and chondrosarcomatous differentiation: A case report.
abstract: BACKGROUND
  Malignant peripheral nerve sheath tumor is an uncommon tumor of the peripheral nerves. The commonest presenting symptom is soft tissue mass and pain with local neurological findings. Imaging modalities are unhelpful in making a reliable diagnosis. Treatment is radical resection with adequate clear resection margins. Radiotherapy improves the local control, but the prognosis remains poor especially in those with divergent differentiation.
  
  
  CONCLUSIONS
  A 23-year-old man with no history of neurofibromatosis presented with a swelling on the back which has been gradually increasing in size and causing him discomfort. The tumor was surgically excised and the histopathological examination revealed malignant peripheral nerve sheath tumor with extensive osseous and cartilaginous differentiation. He developed pulmonary metastases one year after the surgical resection. Pulmonary metastatectomy was therefore performed and the histopathology of the metastatectomy specimen revealed metastatic malignant peripheral nerve sheath tumor, but without any osseous or cartilaginous differentiation. He remained well with no recurrence or metastases at 9-month follow-up.
  
  
  CONCLUSIONS
  Malignant peripheral nerve sheath tumor is a malignant tumor that behaves aggressively despite adequate radical resection. This case also illustrates extensive osseous and cartilaginous divergent differentiation of the primary tumor which was surprisingly absent in the metastatic lesions. This finding warrants further research.
authors.affiliation: General and Minimally Invasive Surgery Section, King Fahad Specialist Hospital, Dammam 31444, Eastern Province, Saudi Arabia. Electronic address: Meshikhes@gmail.com.
authors.forename: Abdul-Wahed N
authors.initials: AW
authors.lastname: Meshikhes
authors.affiliation: General and Minimally Invasive Surgery Section, King Fahad Specialist Hospital, Dammam 31444, Eastern Province, Saudi Arabia.
authors.forename: Mohammed A
authors.initials: MA
authors.lastname: Duhaileb
authors.affiliation: Department of Surgery and Department of Pathology and Laboratory Medicine, King Fahad Specialist Hospital, Dammam 31444, Eastern Province, Saudi Arabia.
authors.forename: Samir S
authors.initials: SS
authors.lastname: Amr
keywords: Case report; Divergent differentiation; Malignant peripheral nerve sheath tumor; Metastasis; Radical resection; Radiotherapy