Painful eccrine spiradenoma containing nerve fibers: a case report.

An eccrine spiradenoma is a rare benign tumor most often seen in the head, neck and upper trunk of young adults. Although spontaneous pain or tenderness is a typical symptom of eccrine spiradenomas, the underlying mechanism has not been fully elucidated. Here, we report the case of a 47- year-old woman who had a spiradenoma in the subcutaneous tissue of her posterior neck accompanied by agonizing pain which was triggered by pressure. Multiple nodular lesions were excised and the typical histopathological findings of spiradenoma were seen. The histopathological architecture of a disorganized nerve fiber encasing the tumor nodules appeared to correlate with the unique clinical symptom of pain.