Maxillofacial malignant peripheral nerve sheath tumours.

The clinical and pathological features of 7 patients with MPNST in the maxillofacial area are reviewed. They occurred in five men and two women; ages ranged from seven to eighty years. The parotid area and infratemporal fossa were the commonest sites (two cases each), followed by the lower lip, cheek and central mandible (one case each). Two had the antecedent of an excised neurofibroma, one with von Recklinghausen's disease and radiotherapy, that had recurred many times. Pathological slides were revised. Immunohistochemistry with S-100 protein was positive in 6 of 7 cases; electron microscopy confirmed the diagnosis in 3 cases. None showed divergent differentiation. Surgical treatment was performed in all, with or without radiotherapy. Surgical margins were positive in five cases. Recurrence took place in six and was multiple in three. Surgical salvage of the local recurrences produced satisfactory results in 3 of the 6 cases. One patient developed lung metastasis.