Bilateral trigeminal schwannomas associated with von Recklinghausen disease.

A 47-year-old woman was admitted on February 7, 1990 with numbness of the left side of her face that had been present for 2 months. This numbness extended from the forehead to the jaw in the distribution of the trigeminal nerve. In 1983 and 1984, the patient had undergone the removal of subcutaneous tumors of the right side of the neck, in both axillae, and along the right flank. The histologic diagnosis of all these tumors was neurofibroma. The patient did not show cutaneous pigmentation, but was diagnosed as having VRD because of the occurrence of multiple neurofibromas. Her daughter also had subcutaneous fibromas and was diagnosed as VRD at another hospital. Neurologic examination showed hypesthesia in the left trigeminal nerve territory. The left masseter muscle was moderately atrophic, but showed good contraction. Other cranial nerves were all intact. Computed tomography (CT) scan demonstrated a low-density mass with ring enhancement extending from the left trigeminal ganglion into the lateral surface of the pons across the apex of the petrous temporal bone (Fig. 1A). Magnetic resonance (MR) imaging detected two abnormal masses. One extended from the left trigeminal ganglion into the lateral surface of the pons and the other at the pontine entry zone of the right trigeminal nerve. The left-sided tumor showed low intensity on T1-weighted image and high intensity on T2weighted image. Both of these masses also showed ring enhancement with Gd-DTPA (Figs. 1B and 1C). After a left subtemporal craniotomy, the left-sided tumor was radically resected. The tumor was cystic and contained dark-brown fluid . After the fluid was evacuated , the tumor was cut into halves. The posterior pieces of the tumor were easily pulled out and the trigeminal nerve was identified at this point. During resection of the anterior portion of the tumor , some venous blood from the cavernous sinus appeared and the operation was stopped at this point. There remains the possibility of some residual tumor within the cavernous sinus. The histologic diagnosis was a schwannoma. The patient was discharged with no neurologic deficits but slight numbness on her left cheek. Follow-up MR 15 months after the operation showed no recurrence of the left-sided tumor and no apparent change of the right-sided tumor. At this time, she complained of very slight left cheek numbness , but no symptoms or signs along the right trigeminal nerve distribution .