Track: Case Reports

Topic: Melanocytic Neoplasms

Abstract:

Melanocytic nevi are common benign lesions with various subtypes categorized by histologic appearance. While prevalence is higher in younger individuals, characteristics of nevi in the elderly are less studied. A subset termed senescent nevi, exhibiting atypical cells, is emerging in this population. Our report presents a case of a senescent compound nevus of the elderly with atypical nuclei. Our patient was a 69-year-old woman who presented with a brown macule on her right central malar cheek, clinically resembling a benign melanocytic nevus or basal cell carcinoma. Biopsy revealed an asymmetric compound melanocytic proliferation with sun-damaged skin, showing atypical features including enlarged dermal melanocytes with hyperchromatic nuclei and pseudo-inclusions. Immunohistochemistry confirmed the diagnosis of a senescent intradermal nevus of the elderly, with negative PRAME and beta catenin, no expression of BRAF and NRAS, and retained expression of P16 and BAP1. In this case, our follow-up recommendations included close clinical monitoring or conservative re-excision due to limited data on recurrence rates. Since elderly individuals are more exposed to ultraviolet B radiation, they are prone to melanocyte senescence. Studies on nevi in this population reveal differences between senescent nevi and benign nevi, with atypical features including solar elastosis and intranuclear pseudo-inclusions. Hence, recognition of senescent nevi in the elderly is crucial to prevent misdiagnosis.