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Pigmented lesions of the oral mucosa: A cross-sectional study of 458 histopathological specimens.

OBJECTIVES
To evaluate clinical, demographic, and histopathological characteristics of pigmented lesions of the oral mucosa.


MATERIALS AND METHODS
A cross-sectional study was conducted over a 64-year period. Information was collected from medical charts, and all archived histopathological specimens with diagnoses of any pigmented lesion were retrieved. Statistical analysis was performed using SPSS software.


RESULTS
A total of 34,127 archived specimens were reviewed, revealing 458 (1.34%) pigmented lesions, of which 230 were melanocytic and 228 nonmelanocytic. Most patients were females (74.2%), white-skinned (49.1%), in the third and seventh decades of life (mean of 45 years). Most lesions were macular (59.8%), followed by plaques and nodules (4.8%), measuring 0-5 mm (41.9%). Cheek mucosa (21.0%), alveolar mucosa (16.6%), and gingiva (11.8%) were the most commonly affected sites. Amalgam tattoo was applied in 212 cases (46.3%), followed by melanotic macule (22.9%) and nevus (20.5%). Other diagnoses included racial pigmentation, exogenous pigmentation, melanotic neuroectodermal tumor of infancy, melanoma, melanoacanthoma, smoker's melanosis, and heavy metal pigmentation.


CONCLUSIONS
Pigmented lesions represent an uncommon diagnosis in oral pathology routines. The most frequent entities are amalgam tattoo, melanotic macule, and nevus. Patients are usually middle-aged women presenting a small, long-lasting, macular lesion on the cheek mucosa.