Congenital Melanotic Macule of the Tongue: Report of Two Cases and Literature Review

Background: Congenital melanotic macule of the tongue (CMMT) has been described as a distinct entity, despite its unknown etiology. However, the diagnosis and management of affected newborns may challenge clinicians and pediatric dentists.

Methods: We document here the clinicopathological findings of two additional cases of CMMT. A literature review of CMMT reports identified across PubMed, Web of Science, Embase, and Scopus was also conducted.

Results: The patients, 2- and 4 month-old Venezuelan boys, respectively, presented at birth with a single or multiple dark-brown-pigmented macule exclusively on the dorsum of the tongue. Histopathological features revealed increased melanin pigmentation in the basal epithelial layer with overlying hyperkeratosis and pigment-laden subepithelial macrophages with normal morphological appearance. Nine studies comprising 17 cases of CMMT have been described hitherto. Most cases were from the USA and France (n = 6 each). Twelve (70.6%) patients were males, eight (50%) were white, and median age was 2.7 months. CMMT presented as brownish to black, solitary or multiple pigmentations located in the right or left region of the dorsum of the tongue, ranging in size from 3.0 to 30.0 mm.

Conclusion: An important feature for the diagnosis of CMMT is the information about the manifestation at birth and consequent proportional growth. This report intends to draw the attention of pediatricians and dentists to this apparently underdiagnosed condition for decision-making and management of affected newborns.