فهرست نشریات علمی دسترسی آزاد ایران

Background: Melanonychia is characterized by a brownish-black discoloration of the nail plate, typically resulting from melanin deposition. Histopathological examination plays a crucial role in determining the etiology and prognosis of affected patients. This study aims to investigate the underlying causes of longitudinal melanonychia through histopathological analysis of biopsy samples from patients presenting with melanonychia.Methods: This cross-sectional study was conducted by reviewing the medical records archived in the histopathology laboratories of university hospitals. Data, including patient demographics (sex, age), histopathological findings, and both initial and final clinical diagnoses, were collected and analyzed using a structured questionnaire. Statistical analyses were performed using SPSS software, using Chi-square and Fisher’s exact test.Results: A total of 123 patients with melanonychia were included in the study. Of these, 40.7% (50 patients) were men, 43.9% (54 patients) were women, 5.7% (7 patients) were boys, and 9.8% (12 patients) were girls. The mean age was 40.49 ± 20.09 years. Histopathological analysis revealed that 27.65% (34 patients) had melanocyte activation, 52.03% (64 patients) exhibited melanocyte hyperplasia, and 20.32% (25 patients) had non-melanocytic lesions. Among adults, the most common causes of melanonychia were melanocyte activation (dueto non-infectious and non-inflammatory conditions) and hematoma, whereas in children, junctional melanocytic nevus was predominant.Conclusion: This study highlights the diverse etiologies of melanonychia across different age groups and genders. While most cases of melanonychia cases in children are benign, adults- particullarly older patients face a higher risk of malignancy, necessitating careful clinical and pathological evaluation.