A Clinicopathologic Study of Melanonychia / 대한피부과학회지

ABSTRACT

BACKGROUND: Melanonychia is a darkening of the nail caused by deposition of melanin or other substances such as exogenous materials, microorganisms, drugs, PUVA, benign elanocytic hyperplasia or nevus, and malignant melanoma. OBJECTIVE: The purpose of this study was to describe the clinicopathologic features of melanonychia. METHODS: We reviewed the medical records, clinical photographs, and histopathologic slides of 25 cases of melanonychia from April 1995 to April 2006 in our department. RESULTS: The most common clinical pattern of pigmentation was longitudinal melanonychia (13 cases), followed by diffuse (9 cases), and focal melanonychia (3 cases). The final histopathologic diagnoses were fungal infection (4 cases), hemorrhage (2 cases), benign melanocytic hyperplasia (5 cases), melanocytic hyperplasia with nuclear atypia (4 cases), melanoma (5 cases), and no specific findings (5 cases). Of 13 cases of longitudinal melanonychia, 4 cases were benign melanocytic hyperplasia, 3 were melanocytic hyperplasia with nuclear atypia and 3 were malignant melanoma. In diffuse melanonychia, 3 were fungal melanonychia and 2 were melanoma. Three cases of focal melanonychia were associated with fungal infection, hemorrhage or no specific findings respectively. CONCLUSION: This study demonstrated variable clinicopathologic features of melanonychia. For the good management of melanonychia, dermatologists should be aware of the various clinical and histopathological features of this condition and recommend nail biopsy for early detection of melanoma when it is necessary.