Figure 1

Patient PRS-NF2, clinical presentation. A-B) PRS-NF2 at age 17 years with severe micrognathia, ocular hypertelorism and microcephaly. Measurements: outer canthal distance 8.3 cm, 25^th %ile; inner canthal distance 4 cm, 3 S.D. above the mean; interpupillary distance 5.5 cm, 25^th %ile; head circumference 52 cm, 2^nd %ile, weight 41.8 kg, 2-1.4 S.D. below the mean; height 156 cm, 10^th-25^th %ile. C-D) MRI of brain shows bilateral cerebellopontine angle tumors (left: 3.1 × 4.6 × 6.1 cm, right: 1 × 1.2 × 1.1 cm; arrows) with mass effect by the left tumor on the brain stem, pons and cerebellum, with associated effacement of the 4^th ventricle, enlargement of the 3^rd and lateral ventricles, enlarged cervical cord and tonsillar herniation. E-F) MRI of spine shows holocord syrinx with large neurofibroma at C7-T1 (E), causing cord compression and canal stenosis. Some of the other extramedullary intradural neurofibromas described in the text are also shown. G-H) Histological analysis of the resected left cerebellopontine angle tumor shows spindled nuclei with dense to finely granular chromatin and cells with long tapering cytoplasmic processes with inconspicuous outer membranes. Panel G demonstrates both short fascicular bundles with dense Antoni type A area (right upper corner) and loose hypocellular Antoni type B area (middle to left lower corner) characteristic of schwannomas (H&E, G-100×). Panel H is 400 × magnification of the inset from panel G).