N J Ball1, L E Golitz. 1. Department of Dermatology, Denver General Hospital, CO 80204.
Abstract
BACKGROUND: We report a variant of melanocytic nevus that may be confused with melanoma. OBJECTIVE: The purpose of this study is to describe the clinical, histologic, and biologic features of nevi with focal atypical epithelioid cell components (clonal nevi). METHODS: Seventy-three cases were retrieved by reviewing lesions previously diagnosed as clonal, combined, deep penetrating, and inverted type-A nevi. Histologic features were assessed and referring physicians received a questionnaire about the presentation and outcome of each case. RESULTS: Histologically, all cases had a biphasic pattern characterized by an ordinary nevus that contained a darkly pigmented collection of large distinct epithelioid melanocytes in the superficial dermis. Immunostains identified mutant p53 proteins in 50% of dermal clones (9 of 18) but not in ordinary nevus cells adjacent to the clones. We are not aware of any patient developing a malignant melanoma (mean follow-up 24.5 months), including 41 cases that were initially incompletely excised. CONCLUSION: Clonal nevi are a distinct variant of melanocytic nevi and should be distinguished from malignant melanoma arising in a preexisting nevus.
BACKGROUND: We report a variant of melanocytic nevus that may be confused with melanoma. OBJECTIVE: The purpose of this study is to describe the clinical, histologic, and biologic features of nevi with focal atypical epithelioid cell components (clonal nevi). METHODS: Seventy-three cases were retrieved by reviewing lesions previously diagnosed as clonal, combined, deep penetrating, and inverted type-A nevi. Histologic features were assessed and referring physicians received a questionnaire about the presentation and outcome of each case. RESULTS: Histologically, all cases had a biphasic pattern characterized by an ordinary nevus that contained a darkly pigmented collection of large distinct epithelioid melanocytes in the superficial dermis. Immunostains identified mutant p53 proteins in 50% of dermal clones (9 of 18) but not in ordinary nevus cells adjacent to the clones. We are not aware of any patient developing a malignant melanoma (mean follow-up 24.5 months), including 41 cases that were initially incompletely excised. CONCLUSION: Clonal nevi are a distinct variant of melanocytic nevi and should be distinguished from malignant melanoma arising in a preexisting nevus.
Authors: Iwei Yeh; Ursula E Lang; Emeline Durieux; Meng Kian Tee; Aparna Jorapur; A Hunter Shain; Veronique Haddad; Daniel Pissaloux; Xu Chen; Lorenzo Cerroni; Robert L Judson; Philip E LeBoit; Timothy H McCalmont; Boris C Bastian; Arnaud de la Fouchardière Journal: Nat Commun Date: 2017-09-21 Impact factor: 14.919