Melanotic schwannoma of the sympathetic ganglia: a histologic, immunohistochemical and ultrastructural study.

We describe the case of a 46-year-old male patient who presented with pain in the left thigh, often accompanied by lumbar pain. These symptoms were sustained by a neoplasm, which was located in the sympathetic ganglia, at the level of the 3rd left lumbar spinal root and which was completely excised. Immunohistochemical positivity for S100, HMB45, and NSE antibodies suggested that the lesion was a melanotic schwannoma (MS), with both schwannian and melanocytic differentiations, the latter containing melanosomes at ultrastructural examination. Non-recurrence after 16 months of follow-up further supports our diagnosis of MS.