CLINICAL CHARACTERIZATION OF PRIMARY ACQUIRED MELANOSIS

Purpose. Primary acquired melanosis (PAM) is the name applied to flat, speckled, brown lesions of the conjunctival epithelium. Because there have been reports that many of these lesions progress to melanoma, bi opsy of all PAM lesions, regardless of size, is recommended. This stud y was undertaken to determine the prevalence of PAM, provide a clinica l description of the condition, and determine which factors are associ ated with its presence. Methods. One hundred forty-six consecutive pat ients, who were outpatients at a corneal and external diseases service , who had no known non-European ancestry, and who were older than 10 y ears of age underwent careful slit lamp examination. Results. The prev alence of PAM in the study population was 36%. Contrary to earlier rep orts, PAM is prevalent in young adults as well as in older patients. T he presence of PAM was associated with southern European ancestry (P = 0.01), dark brown hair (P = 0.01), facial nevi (P = 0.03), pinguecula e or pterygia (P = 0.01), hypertension (P = 0.02), cigarette smoking ( P = 0.02), and the absence of ocular surface disease (P = 0.02). Concl usions. Because PAM is common, its transformation to conjunctival mela noma must be extremely rare, and biopsy of all PAM lesions is unwarran ted. In the absence of known clinical risk factors for progression to melanoma, interim recommendations are made to perform biopsy only of t hose lesions that are widespread, large, thickened, dark, palpebral, u nusually vascular, or progressive.