Pointillist nevi.
BACKGROUND: Atypical melanocytic nevi and cutaneous melanoma are often marked by variation in color. However, there are examples of "benign" explanations for irregularities in pigmentation, such as perifollicular hypopigmentation or hyperpigmentation. OBJECTIVE: The purpose of this study was to correlate the clinical and histologic features of 3 unusual melanocytic nevi consisting exclusively of multiple, tiny, dark brown to black dots on a skin-colored background, which we have termed pointillist nevi. METHODS: Histologic examination was performed of the single pointillist nevus from each of 3 patients (all women; aged 28, 39, and 47 years). RESULTS: The diameters of the pointillist nevi were 2, 3.5, and 5.5 mm. Individual dots were approximately 0.1-0.25 mm. Each of the 3 nevi showed a different histologic correlate for the dots, either (1) discrete, densely pigmented, junctional melanocytic nests; (2) isolated dermal pigmented melanocytic nests; or (3) discrete clusters of melanophages in the papillary dermis. CONCLUSION: Pointillist nevi are benign melanocytic nevi with histologic correlates similar to those of the "brown globules" observed by dermoscopy in uniformly pigmented nevi. However, the dots seen in pointillist nevi can be visualized without magnification. The clinical and histologic features of pointillist nevi add to the spectrum of unusual patterns of pigmentation that may be encountered in benign melanocytic lesions.