Palisaded encapsulated neuromas (PENs) are benign cutaneous nerve sheath proliferations that typically occur as flesh-colored papules solitarily on the head and neck in adults, with a slight predilection for females. Histopathologically, they are partially or completely encapsulated intradermal nodules with Schwann cells and axons in fascicles separated by clefts. Although these features are often characteristic, the hypercellular variant of PEN can pose a diagnostic challenge in distinguishing between other cellular neural and melanocytic lesions. We herein report a case of hypercellular PEN, which showed striking similarity to desmoplastic melanoma.
*Department of Pathology, University of Washington School of Medicine, Seattle, WA; and
†Dermatopathology and Oral Pathology Service, University of California San Francisco, San Francisco, CA.
Correspondence: Caitlin May, MD, Department of Pathology, University of Washington School of Medicine, 1959 Northeast Pacific Street, Box 356524, Seattle, WA 98195 (e-mail: firstname.lastname@example.org).
The authors declare no conflicts of interest.