Unusual Histopathological Findings of Intradermal Nevus: Retrospective Analysis of 2640 Cases

Abstract

Background: intradermal nevi are benign tumors of the skin and may be accompanied by different histopathological findings. Objective: The aim of this study was to assess co-existing unusual histopathological findings in specimens resected with a preliminary diagnosis of an intradermal nevus. Design: Retrospective study Setting: Education and research hospital Subject and Methods: We retrospectively examined demographic and histopathological data of 2640 cases resected with a preliminary diagnosis of an intradermal nevus between January 2010 and April 2018. Results: A total of 1973 women and 667 men with an age range of 2.8 to 94 years were enrolled. Among cases having a histopathological diagnosis of intradermal nevus, 46 cases had unusual histopathological findings, which included 21 osseous metaplasia, 8 epidermal cysts, 4 folliculitidis, 1 seborrheic keratosis, 1 verruca vulgaris, 1 cavernous hemangioma-intravascular papillary endothelial hyperplasia, 1 trichofollicoma, 1 sebaceous hyperplasia, 1 pilonidal sinus, 1 granulomaous inflammation, 1 basal cell carcinoma, 4 foreign body reactions, and 1 Demodex spp. Conclusion: Although unusual histopathological findings were observed in a minority of cases with intradermal nevi, it was noted that problems with differential diagnosis may arise in some cases. Intradermal nevi need to be carefully examined for potential co-existing neoplastic lesions.