Pigmented lateral periodontal cyst and other pigmented odontogenic lesions

OBJECTIVE: To report a case of lateral periodontal cyst (LPC) with marked melanin pigmentation in a 38-year-old Black male and to discuss the phenomenon of melanin pigmentation in odontogenic cysts and tumors. RESULTS: Histologically, the epithelial lining of the LPC contained an abundant amount of melanin granules throughout the entire epithelium. Ultrastructurally, epithelial cells contained mature melanosomes (stage IV melanosomes). Melanophages containing aggregates of melanosomes were identified in the connective tissue cyst wall. Perusal of the literature revealed that melanin pigmentation in odontogenic lesions is uncommon. Melanin has been reported in calcifying odontogenic cyst (18 cases), odontogenic keratocyst (8 cases), adenomatoid odontogenic tumor (3 cases), ameloblastic fibroma (3 cases), odontoma (2 cases), and amelobastic fibro-odontoma, odonto-ameloblastoma, and odontogenic fibroma (I case each). CONCLUSIONS: Almost all pigmented odontogenic lesions occurred in Blacks and Asians; they are almost non- existent in Whites. Thus, racial pigmentation probably plays an important role in such lesions.