CHARACTERIZATION OF A MELANOTIC MACULE. CORRELATION BETWEEN DERMOSCOPY AND HISTOLOGY

Dermoscopy is a non-invasive in vivo diagnostic technique that allows analyzing the morphologic features of pigmented lesions, using different incident light magnification systems with an oil immersion technique or polarized light. Although the role of this technique has been defined extensively for skin lesions, there is little evidence in the literature on its usefulness as a diagnostic tool for mucosal pigmented lesions.OBJECTIVE:To describe the clinical, dermoscopic, and histologic features of oral melanotic macules and to estimate the agreement between dermoscopic and histopathological patterns. MATERIALS AND METHODS: A descriptive prospective longitudinal study was performed. Clinical, dermoscopic, and histologic examination of patients with oral pigmented lesions presenting at the Oral Medicine Department of the School of Dentistry, University of Buenos Aires, was performed. RESULTS: The study comprised twenty- five patients, 56% of whom had a melanotic macule (14 cases), 24% had post-inflammatory alterations (6),4% had a tattoo (1), 4% a nevus (1), 4% melanoma (1),4% ethnic-type pigmentation (1) and 4% had lichenoid actinic cheilitis (1). The melanotic macules appeared as single lesions in 28.5% of cases (4), as multiple lesions (from 1 to 4) in 7% (1), and as more than 5 lesions in 64.5% (9) of cases. The most frequent localizations were the lip mucosa 50% (7), the gingiva 22% (3), the cheek mucosa 14% (2), semi-mucosa 7% (1), and the alveolar ridge 7% (1). Dermoscopy of the melanotic macules showed parallel lines, fish scale-type or hyphal pattern in 85.7% of cases (12), aggregated globules in 35.7% (5), structureless areas in 35.7% (5), a veil in 7.1% (1), a pigment network in 0% of cases. One-hundred percent of cases showing lines, fish-like or hyphal pattern corresponded histologically with an increase in melanin or melanocytes in the basal layer. CONCLUSIONS: The dermoscopic finding of lines, a fish-scale or a hyphal pattern correlated with histologic diagnosis of melanotic macule. A veil or structureless areas were observed in lesions located in the attached gingiva, which leads us to suspect that dermoscopy is less useful at these sites. Grant: UBACYT CO013