[Pigmentations of the oral cavity].

Buccal mucosa color is explained by hemoglobin in the vessels and melanin in the epithelium. Abnormal presence of melanin pigments (hypermelaninosis, hypermelanocytosis), hematic pigments (hemoglobin, hemosiderin, iron) but also some exogenous circonstancies explain pigmented lesions (figure 1). These lesions could be localized (single lesions), multifocal (multiple lesions) or diffused. In case of a localized pigmentation with melanic appearance, melanoma must be systematically eliminated with a biopsy. In the case of a more diffused lesion, systemic disease must be evoked. A drug etiology is also possible. A blood pigment excess could be a vascular malformation (flat lesions) or a tumoral process (nodular or swollen lesions). In both cases, Kaposi's disease should be systematically eliminated. Pigmentations near dental restorations (amalgams, prosthetic crowns) could be explained by an exogenous factor but a biopsy should be performed in case of a doubt with melanoma.