Pigmented Lesions of the Oral Mucosa

Healthy oral soft tissues present a typical pink to red with slight variations of color due to many reasons presence or absence of keratin on the surface epithelium, the quantity, superficial or deep location of blood vessels in the subjacent stroma, the existence of lobules of adipocytes, the absence of melanin pigmentation in the basal cell layer of the epithelium oral and perioral pigmentation may be physiologic in nature, particularly in individuals with dark skin complexion, in the course of disease, the oral mucosa and perioral tissues can assume a variety of discolorations, including brown, blue, gray, and black. Such color changes are often attributed to the deposition, production, or increased accumulation of various endogenous or exogenous pigmented substances. However, although an area may appear pigmented, the discoloration may not be related to actual pigment but rather to the deposition or accumulation of organic or inorganic substances, including various metals and drug metabolites. The most common endogenous sources of mucosal color change is hemoglobin, hemosiderin, and melanin.