Dysplastic nevi and malignant melanoma: insights into pre-biopsy diagnostic accuracy and the critical role of dermatology consultation.

A dysplastic nevus (DN) is an acquired melanocytic nevus that displays clinical and histological features similar to malign melanoma (MM). This study aims to evaluate the demographic and clinical characteristics of DN and primary cutaneous MM, as well as assess the accuracy of pre-biopsy diagnoses. We retrospectively analyzed 206 histopathologically confirmed cases of DN (n = 185) and MM (n = 21) from 159 patients at a tertiary care center. The biopsy samples had been sent from both dermatology and other surgical departments. The study included 21 patients with MM and 139 with DN; one patient had both conditions. The mean age was 60.6 ± 15.9 years for MM patients and 34.7 ± 14.9 years for DN patients, both with a slight male predominance. Melanomas were predominantly on the face (42.9%), whereas DN lesions were mostly on the trunk (76.8%). Breslow thickness analysis showed 33.3% of MM tumors were < 1 mm and 28.6% were > 4 mm. In 90.5% of MM cases and 71.4% of DN cases, preliminary diagnoses of MM and/or DN were noted on pathology request forms. Overall, pre-biopsy diagnoses were consistent with final diagnoses in 73.3% of the 206 lesions. Diagnostic accuracy was higher in dermatology compared to other surgical departments (85.8% vs. 50%, p <.00001) and was better for trunk and feet locations compared to unspecified areas (p = .023 and p = .044, respectively). The study highlights the need for dermatology consultation before excising nevi or suspicious lesions and emphasizes early melanoma detection. Despite the small sample size, it underscores the importance of enhanced screening methods and awareness campaigns.