Extrathoracic malignant peripheral nerve sheath tumor of the lateral chest wall locally recurred and metastasized to peritoneum: Report of a case

Malignant peripheral nerve sheath tumors (MPNSTs) are rare, with an expected incidence of 0.0001% per year in the general population and 4.6% in patients with von Recklinghausen's disease. They are defined as any malignant tumors arising or differentiating from cells of the peripheral nerve sheath. MPNSTs can develop in various sites including the trunk and head/neck region. However, its onset on the chest wall is very rare. Here we report a case of MPNST growing outside the thorax on the chest wall. The patient developed a local recurrence twice, which caused multiple metastases to the lung and peritoneum.