Fig. 1

Clinicopathologic features of orbitofacial neurofibroma. Five year-old boy with neurofibromatosis type 1 with orbitofacial neurofibroma at first presentation (a) and recurrence 3 years post-treatment (b). Neurofibromas in this region are notoriously difficult to treat and may involve a variety of orbitofacial structures. This example extends to the ipsilateral cavernous sinus (c). Histologic evaluation in these tumors frequently demonstrates plexiform (d) and diffuse (e) patterns, frequently coexisting (f). Immunohistochemistry consistently demonstrates strong expression of S100 (g), SOX10 (h), and CD34 (i)