Multiple palisaded encapsulated neuromas presenting as cobblestoned plaques over palms and oral cavity

Palisaded encapsulated neuroma (PEN) is a benign circumscribed nerve sheath tumor usually seen as a solitary painless papule on the face in middle-aged adults. We report a 22-year-old male with multiple adolescent-onset PENs distributed extensively, including the oral cavity and palms, contrary to the typical presentations. The lesions formed cobblestoned plaques and were confirmed through a skin biopsy, showing characteristic nodules of wavy spindle cells forming interlacing fascicles with interspersed clefts, and positive staining for specific markers, including markers for axons and perineurium. Notably, this case deviates from the usual presentation, shedding light on atypical manifestations of PEN in a young individual without any features suggestive of a neurocutaneous syndrome or multiple endocrine neoplasia syndrome.