Perineurioma of the posterior interosseous nerve: surgical treatment.

Intraneural perineurioma is a benign tumor that occurs in less than 1% of peripheral nerve tumors; no more than 90 cases have been reported1,2. Tumorous lesions of the posterior interosseous nerve (PIN) have rarely been described3–5. An 18-year-old woman presented with a longstanding his tory of spontaneous progressive weakness in the PIN dis tribution (Figure 1). Ultrasonography and MRI studies (Figure 2) showed a nodular lesion in the PIN, measuring 1.0 cm at its greatest diameter. At surgical exploration a tumor (Figure 3) involving all the nerve fascicles was entirely re sected. The nerve was repaired by termino-terminal neurorrhaphy. Figure 4 shows the histological examination.