title: Palisaded encapsulated neuroma (PEN): an often misdiagnosed neural tumor.
abstract: We describe a unique case of a young man with concomitant Fragile X syndrome who presented with a dome-shaped pearly papule under the nose that had enlarged over 9 months. Histology demonstrated a smoothly contoured spindle cell neoplasm of the dermis with neuroid structures and foci of palisaded growth, consistent with a diagnosis of palisaded encapsulated neuroma (PEN). Palisaded encapsulated neuroma is a benign neural neoplasm of the skin or mucosa that displays histologic features of both a neurofibroma and a schwannoma. However, unlike these tumors, PEN lacks the implications for underlying systemic disease or malignancy. Palisaded encapsulated neuroma is a commonly underdiagnosed and misdiagnosed tumor that, once identified clinically and histologically, can be easily excised without recurrence.
authors: Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, USA.
authors: Marissa D
authors: MD
authors: Newman
authors: Sandy
authors: S
authors: Milgraum
mesh_terms: D000328:Adult; D001707:Biopsy, Needle; D002277:Carcinoma / Q000175:diagnosis / Q000473:pathology*; D003937:Diagnosis, Differential; D005145:Face; D005153:Facial Neoplasms; D005500:Follow-Up Studies; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D009463:Neuroma / Q000175:diagnosis / Q000473:pathology* / Q000601:surgery*; D018570:Risk Assessment; D012878:Skin Neoplasms / Q000175:diagnosis / Q000473:pathology* / Q000601:surgery*; D016896:Treatment Outcome