Consider melanoma, smoker's melanosis, when diagnosing pigmented oral lesions

Boston - Clinicians cannot assume a patient who presents with oral pigmentation has a benign condition, due to endogenous and exogenous pigment that can reflect local and systemic process, says Ginat Mirowski, D.M.D., M.D., F.A.A.D., a dermatologist and professor of oral pathology, medicine and radiology, Indiana University School of Dentistry, Indianapolis.

"We must consider other conditions, including smoker’s melanosis, drugs, Addison's disease and even melanoma,” Dr. Mirowski says.

Pigmentation of the gingivae is commonly benign, a physiologic condition that affects the attached gingivae in a symmetric fashion and spares the free gingival margin, said Dr. Mirowski at the 2012 American Academy of Dermatology Summer Academy Meeting. Physiologic pigmentation occurs more commonly in individuals of color than in Caucasians, and its prevalence rises with age.

If there's involvement of the free gingival margin, however, "It's more likely to be melanoma," she says. In such cases, she recommends performing a biopsy.

Smoker’s melanosis
In smoker’s melanosis, experts theorize that an unknown component in tobacco stimulates melanocytes to increase melanin production, Dr. Mirowski says. In a study of 908 Turkish army recruits, the rate of smoker’s melanosis was 27.5 percent in smokers versus 8.6 percent among recruits who had never smoked (Marakoğlu K, Gürsoy UK, Toker HC, et al. Mil Med. 2007;172(1):110-113).

"Smoker’s melanosis is more common in pipe smokers, but it's also seen in cigarette smokers,” she says, adding that the condition is also associated with the use of birth control pills. It most commonly affects the anterior labial gingiva (usually in the anterior mandibular area), although it can impact the palate and buccal mucosa, she explains. The condition is reversible if the patient stops smoking.

Addison’s disease
Other oral conditions to consider include Addison's disease, which can be a life-threatening condition, Dr. Mirowski says.

"Addison's disease occurs when patients lose their ability to produce steroids,” she says. “The insidious onset - and the associated fatigue, irritability, depression, anorexia, weight loss and salt cravings - are all nonspecific findings. Interestingly, pigmentation of the dorsal and lateral tongue precedes bronzing of the skin (in response to increased beta-lipoprotein or adrenocorticotropic protein)."

Treatment requires low-dose daily corticosteroid replacement, Dr. Mirowski says.

Disclosures: Dr. Mirowski reports no relevant financial interests.

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