Melanin pigmented dentigerous cyst report of a case and review of relevant literature

Melanin pigmentation has been identified as a distinguishing feature in odontogenic cysts and tumors. In this study, a melanin-pigmented dentigerous cyst was observed in a 27-year- old Black man involving the left maxilla. Pigments within the lesion were confirmed as melanin by Masson-Fontana staining. The presence of melanocytes within the epithelial cyst lining was demonstrated by S-100 and Melan-A immunostaining. HMB-45 a marker for melanoma cells was negative. Studies of odontogenic pigmented lesions reported in the literature differ in type and in the histochemical, Immunohistochemical, and ultrastructural methods used; however, all have consistently demonstrated that the pigment is melanin. A PubMed/ Medline search of the literature revealed 69 pigmented odontogenic cyst and neoplasms reported to date with the inclusion of the current case. The presence of cholesterol clefts within the cyst lumen with the localization of melanin pigment within the clefts was a unique and distinctive finding of the present case. This study aims to report an unusual case of dentigerous cyst with marked macroscopic melanin pigmentation, unique histologic localization of the pigment within the cholesterol clefts, discuss the phenomenon of melanin pigmentation in odontogenic cysts and tumors, and to review the relevant literature.