Longitudinal Melanonychia in Korean Patients: A Clinical and Histopathologic Study of 75 Cases / 대한피부과학회지

BACKGROUND: Longitudinal melanonychia (LM) can be challenging as it may be caused by a wide variety of benign and malignant conditions. However, there are scarce data on LM confirmed by skin biopsy examination in Korean patients. OBJECTIVE: We sought to evaluate the clinical features and histopathologic diagnosis of LM in Korean patients. METHODS: We reviewed the medical records and clinical photographs of patients presenting with LM confirmed by skin biopsy examination between June 2007 and June 2017. RESULTS: Among a total of 75 patients with LM confirmed by skin biopsy examination at our hospital over a period of 10 years, 11 patients (14.7%) had malignant lesions. Common features of malignant lesions were involvement of a single nail, color heterogeneity, Hutchinson's sign, and nail plate dystrophy or ulceration. Common features of benign lesions were a negative Hutchinson's sign and absence of nail plate dystrophy and ulceration. CONCLUSION: This study analyzed the clinical features and histopathologic diagnosis of LM in Korean patients. Our data may contribute to determining the management approach for patients with LM.

A Case of Melanonychia Striata Caused by Congenital Melanocytic Nevus / 대한피부과학회지

A number of conditions can cause melanonychia striata, but its main importance is that it may indicate the presence of a subungual melanoma. A biopsy of the nail matrix can be performed to rule out melanoma, but nail matrix boipsies sometimes result in a permanent nail deformity. Since the incidence of melanoma in children is quite small, there is some controversy as to whether this procedure should routinely be performed in the pediatric age group. We report a 7-year-old boy with melanonychia striata resulting from a congenital melanocytic nevus.