Pigmented lesion with characteristics of malignancy: a case report

Abstract

Pigmentations of the oral mucosa include a range of lesions or conditions that manifest as changes in the color of oral tissues; these changes may show melanocytic activity. A melanotic macule is a small, well-circumscribed melanocytic benign lesion. It can occur on the lips and intraorally and ranges in color from brown to black. Microscopically, it is characterized by elevated levels of melanin production by basal melanocytes, which appear normal in terms of number, morphology, and distribution. A 48-year-old woman sought treatment for a pigmented lesion that had been present for 4 months. Intraoral examination revealed a non-homogenous brownish spot (measuring 0.7 cm) with irregular borders on the left side of the soft palate. Since the lesion had an atypical clinical appearance, melanocytic nevus, oral melanoacanthoma, and oral malignant melanoma were considered in differential diagnoses. After an incisional biopsy, the lesion was diagnosed as a melanotic macule. Due to their varying clinical appearance, benign pigmented lesions can be mistaken for malignant tumors, especially when the lesions exhibit similar coloration, symmetry, and borders. Through this report on a case with atypical clinical characteristics, we aim to reinforce the ubiquitous nature of oral pigmented lesions, and the importance of employing different approaches to diagnosing these lesions.

Keywords: melanotic macule; oral malignant melanoma; pigmented lesion.