Plexiform Schwannoma of Lumbar Region.

Plexiform schwannoma is an unusual peripheral nerve sheath tumor. It can mimic plexiform neurofibroma. A five-year-old girl presented with painful swelling in left lumbar region. Radiologic investigations showed a multinodular tumor in the subcutaneous plane of lumbosacral region. A complete excision and histopathologic examination revealed a plexiform tumor composed of hypocellular and hypercellular areas with verocay bodies. The tumor cells showed strong positivity for S-100 protein, rendering a final diagnosis of plexiform schwannoma. The child has been free of recurrence in 12-month follow-up.