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Sir,

Patients with neurofibromatosis type 2 (NF-2), a rare autosomal dominant disease caused by mutations in the NF-2 tumour-suppressor gene on chromosome 22q12,1 are predisposed to central nervous system tumours. Paediatric presentation is not yet well defined and differs from adult onset as the diagnostic criteria2 are often not met at initial clinical manifestation.3

This report describes a boy with a trigeminal and a plexiform schwannoma and juvenile cataract without bilateral vestibular schwannomas and lacking a positive family history, who was diagnosed with NF-2.

Case report

A 10-year-old boy was referred by the paediatric ward with a 3-week history of recurrent vomiting, lack of appetite, weight loss, frontal headaches, and inattentiveness at school. Psychiatric assessment indicated an onset of anorexia/bulimia with functional headaches possibly due to social and school problems.

Pre-existing diagnoses were posterior subcapsular lens opacity in the right eye (Figure 1) with amblyopia, esotropia, and dissociated vertical divergence. Strabismus surgery had been performed at 7 years of age. Ocular motility had not been restricted. A plexiform schwannoma of the thorax had also been excised.

Figure 1
figure 1

The left eye presents with a posterior subcapsular lens opacity.

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On ophthalmologic examination, visual acuity measured 20/50 in the right and 20/25 in the left eye. Ocular motility testing showed extensive limitation of right abduction. Sensory function of the right trigeminal nerve was markedly diminished.

At 2 weeks after a CT scan of the head—that notably had been reported as unremarkable—a subsequent MRI detected an extraaxial mass at the right petrous apex extending forward into Meckel's cave and the cavernous sinus (Figure 2). This tumour had originated from the right trigeminal nerve and was subtotally removed in a one-stage procedure. Histological examination confirmed the diagnosis of schwannoma. Concurrence of juvenile cataract and schwannomas led to the suspicion of NF-2. Genetic testing revealed a nonsense-mutation of the NF-2 gene.

Figure 2
figure 2

Gadolinium-enhanced axial T1-weighted MRI shows a mass at the right petrous apex extending forward into Meckel's cave and the cavernous sinus with intense inhomogeneous peripheral ring enhancement.

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Comment

Further refinement of the diagnostic systems2 for NF-2 in both children and adults is of great importance for early detection of this debilitating disease. NF-2 should be included in the differential diagnosis in patients with isolated schwannomas comprising a close look for further features typical of NF-2 and the use of genetic testing as a diagnostic tool.