Cutaneous epithelioid malignant schwannoma: review of the literature and case report.

A case of malignant epithelioid schwannoma in the skin is reported. This was a rare variant of a malignant tumour that arose on the back of a 35-year-old male without neurofibromatosis. Clinically the nodule appeared to be a benign cyst but as it was painful it was decided to remove it. Ultrastructural and immunohistochemical features of the lesion were consistent with those of malignant epithelioid schwannoma so a radical excision was performed. Most ordinary malignant schwannoma are located in the deep soft tissue of the proximal portions of the upper and lower extremities and trunk; to the best of our knowledge only 26 cases of malignant epithelioid schwannoma in the skin and subcutis have been described in the literature. For the 14 male and 12 female patients reviewed, the median age was 43 years (range 19-84). Upper extremities were the most common sites (10 of 26). Seven patients developed local recurrences and four developed metastases: two to lung, one to lung and lymph node, and one to lung, liver and brain. All patients with local recurrence and all except one who developed metastases did not undergo wide local excision. We can conclude that malignant epithelioid schwannoma in the skin and subcutis is eminently curable if treated with wide local excision.