A simultaneous presentation of uncommon, pigmented lesions: Oral melanoacanthoma and moderate oral epithelial dysplasia.

Introduction: Melanin-containing mucosal lesions can present a diagnostic challenge due to the presence of a wide range of lesions with a similar clinical appearance. Case description: This is a report of a unique case of the simultaneous presentation of 2 pigmented lesions in a 68-year-old white female patient. Discussion: The first pigmented lesion on the ventral tongue was diagnosed as melanoacanthoma, which does not have any potential for malignant transformation. The ventral tongue is a very unusual location for a melanoacanthoma. Interestingly, another lesion on the buccal mucosa with a similar appearance presented as moderate epithelial dysplasia with increased melanin pigment that has the potential for malignant transformation. Pigmented moderate oral epithelial dysplasia is a very rare condition. The simultaneous presence of a melanoacanthoma would have led to a mistaken assumption of multifocal melanoacanthoma which, although rare, has been described in the literature. Conclusion: These findings reinforce that it is prudent to perform multiple biopsies of all suspicious oral lesions.