[Pigmented lesions of the mucosa]

Pigmented lesions of the mucosa are a common reason to consult a dermatologist. They have heterogeneous etiologies and comprise a wide range of differential diagnoses. Both practitioners and patients are often uncertain about the malignancy of the lesions.

Review and demonstration of the most common pigmentation disorders of the mucous membranes, including discussion of clinical findings and underlying causes.

Pigmented mucosal lesions can be classified as either focal or multifocal-diffuse. Focal hyperpigmentation encompasses melanotic macules, nevi, deposition of exogenous materials or pigments, and oral melanoacanthoma. They are mostly benign but must be discerned from mucosal melanoma with an aggressive course and poor prognosis. Multifocal or diffuse hyperpigmentation may be drug-induced or indicative of an underlying medical condition. Importantly, as part of hereditary syndromes further diagnostic work-up is required.

Specific knowledge of the distribution and causes of pigmented mucosal lesions helps in clinical assessment between benign findings and those requiring further work-up and histologic clarification.