Can a black pigmented lesion of the oral cavity predict future development of melanoma- Report of a case and review of literature

Abstract

Oral melanotic macules and primary oral malignant melanoma are distinct pigmented lesions that can present clinical challenges in diagnosis. While melanotic macules are generally benign, quite a few instances of progression to melanoma have been reported. We present the case of a 42-year-old female with gradually enlarging painless pigmented macules on her lips, diagnosed as oral melanotic macules after histopathological evaluation. Although no signs of melanocytic hyperplasia or dysplasia were found, the patient was closely monitored due to the lesion's increasing size over 3 months. This case highlights the importance of distinguishing between benign pigmented lesions, which have a propensity to undergo malignant transformation from those that show no such tendency. Presences of histopathological features like atypical melanocytes and melanocytic hyperplasia/dysplasia in benign pigmented lesions are important markers for malignant transformation. Close clinical follow-up is essential to ensure timely intervention if the lesion exhibits suspicious changes.

Keywords: Malignant transformation; melanocytic dysplasia; melanoma; melanotic macule; peutz-jeghers syndrome; premalignant lesion.

Figure 1

Showing the extra-oral presentation of the patient

Figure 2

Showing the intra-oral presentation of the patient in the upper lip (a) and the lower lip (b)

Figure 3

Showing the photomicrograph of the H and E stained section of the specimen that reveals the presence of stratified squamous epithelium backed by fibrous connective tissue stroma. The juxta-epithelial region shows the presence of diffuse melanin pigmentation along with the presence of melanocytes and melanophages under 10X (a) and 40× (b). Multiple nests of melanin pigment with epithelial cells can be appreciated in the epithelium