Overlapping large facial nevus spilus and nevus of Ota: A case report diagnosed with dermoscopy and reflectance confocal microscopy.

We report a rare case of large facial hyperpigmentation in a 25-year-old female. Starting one month after birth, the patient developed a blue-brown patch on the right side of her face, interspersed with black macules and papules. As she aged, the lesion progressively enlarged and darkened, eventually covering the entire right side of her face. Dermoscopic and reflectance confocal microscopy examinations indicated nevus spilus in some areas and nevus of Ota in others, leading to a definitive diagnosis of overlapping nevus spilus and nevus of Ota. With no signs of malignant transformation on clinical or imaging examination, successful treatment was achieved using Q-switched alexandrite laser without any adverse effects. Our case underscores the critical value of dermoscopy and reflectance confocal microscopy in diagnosing rare facial pigmentary conditions, as we compare the imaging characteristics of nevus spilus, nevus of Ota, and similar conditions, alongside their clinical and histopathological correlations. Furthermore, our findings highlight the significant role of imaging examinations in monitoring malignancy and guiding treatment decisions.