Related Experiment Videos
Longitudinal melanonychia in children: a clinical and histopathologic study of 40 cases
S Goettmann-Bonvallot1, J André, S Belaich
1Department of Dermatology, Hôpital Bichat, Paris, France.
Insights
Longitudinal melanonychia in children is often benign, with most cases caused by melanocytic hyperplasia (lentigo or nevus). Functional melanonychia, due to melanocyte activation, also occurs, but melanoma is not found in pediatric cases.
Area of Science:
- Dermatology
- Pediatric Dermatology
- Nail Disorders
Background:
- Longitudinal melanonychia in children is infrequently documented.
- Understanding the etiology of pediatric nail pigmentation is crucial for accurate diagnosis and management.
Purpose of the Study:
- To investigate the nature of melanocytic lesions in pediatric patients presenting with longitudinal or total melanonychia.
- To identify correlations between clinical presentation and histological findings in these cases.
Main Methods:
- A retrospective review of pediatric patients (<16 years) with longitudinal or total melanonychia evaluated between 1993 and 1996.
- Clinical and histological features of nail conditions were analyzed for each patient.
Main Results:
- Out of 40 pediatric patients, diagnoses included nevus (47.5%), lentigo (30%), and functional longitudinal melanonychia (22.5%).
- Melanoma was not diagnosed in any patient.
- Features like early onset, periungual pigmentation, and total melanonychia were associated with melanocytic hyperplasia but were not pathognomonic.
Conclusions:
- Benign melanocytic hyperplasia (lentigo or nevus) accounted for the majority (77.5%) of pediatric longitudinal melanonychia cases.
- In white pediatric patients, benign melanocytic hyperplasia represented 85% of cases.
- The remaining cases were attributed to melanocytic activation without hyperplasia.
Objective:
Very little has been published on longitudinal melanonychia in children. Our objective was to determine the nature of melanocytic lesions in pediatric patients with longitudinal or total melanonychia and to look for correlations between clinical and histologic features.
Methods:
All patients younger than 16 years of age with longitudinal or total melanonychia who were evaluated at our nail disorder outpatient clinic between September 1993 and September 1996 were included. The clinical and histologic features of the nail condition were determined in each case.
Results:
Forty patients were included. The final diagnosis was nevus in 19 cases (junctional in 17 cases and compound in 2), lentigo in 12 cases, and functional longitudinal melanonychia in 9. The latter corresponded to a hyperpigmentation caused by melanocytic activation with no increase in the number of melanocytes. None of the patients had melanoma. Appearance within the first year of life, periungual pigmentation, and total melanonychia were consistent features in patients with melanocytic hyperplasia (lentigo or nevus). Early onset of a dark broad lesion in a white patient was typical of melanocytic hyperplasia, although none of these features were pathognomonic.
Conclusion:
Benign melanocytic hyperplasia (lentigo or nevus) was the cause of 77.5% of cases of longitudinal melanonychia in our overall pediatric population and of 85% of cases in the subset of white patients. All the remaining cases of longitudinal melanonychia were the result of melanocytic activation.