Multiple isolated cutaneous plexiform schwannomas

Abstract

Plexiform schwannoma is a rare neurogenic tumor, arising from skin and subcutaneous tissue. The presence of multiple schwannomas suggests a possible association with neurofibromatosis type 2 (NF2). A 50-year old male patient presented with multiple papulo-nodular cutaneous lesions on both arms and forearms. Histopathological examination revealed a dermal multinodular pattern of well-circumscribed masses of closely packed cells, with peripheral myxoid tissue, well-encapsulated in a thin collagenous capsule. S-100 immunohistochemical staining was diffusely and strongly positive. Neuron-specific enolase was positive, confirming a neural tissue tumor. An audiogram and Magnetic Resonance Imaging (MRI) of cerebro-pontine angle showed no detected abnormality, excluding acoustic neuroma. Thus, we present a case of multiple bilateral isolated cutaneous plexiform schwannomas, not associated with NF2. Multiple plexiform schwannomas is a very rare entity, distinct from neurofibromatosis (NF), and being confined to the dermis is even more rarely reported.