Dermoscopic and Reflectance Confocal Microscopy Findings in Extra-genital HPV16-associated Pigmented Squamous Cell Carcinoma in situ

Melanoacanthoma: a potential pitfall of reflectance confocal microscopy

Melanoacanthoma is a rare variant of seborrheic keratosis, which is notable for dark pigmentation and fast radial growth, making it difficult to distinguish from melanoma. Histologically, it is characterized by proliferation of keratinocytes and dendritic melanocytes. The authors report a scalp lesion, fast growing, suspected by dermoscopy and confocal microscopy examination, with dendritic cells distributed throughout the lesion. Based on these findings, it was not possible to classify this lesion as clearly benign, so it was excised. Histopathologic evaluation and immunostain were consistent with melanoacanthoma.

The role of reflectance confocal microscopy in a case of Bowen's disease difficult to diagnose

There have been limited reports describing reflectance confocal microscopy (RCM) features of Bowen’s disease (BD). Herein, we describe the RCM features of a pigmented BD with atypical dermoscopic features, mimicking a melanoma. This case highlights the importance of RCM in a challenging BD.