Sebaceoma on the nose mimicking basal cell carcinoma: Pitfalls of dermoscopy and reflectance confocal microscopy

Abstract

Sebaceoma is a rare benign sebaceous tumor that usually occurs on the face and scalp. We report a case of a 3-mm solitary pink papule on the nose in an elderly woman. Dermoscopic examination showed yellow-pinkish background with a central yellow homogeneous structure, peripheral branching vessels (crown vessels), and scattered gray or reddish-brown irregular areas. Reflectance confocal microscopy (RCM) revealed tumor islands with massive dendritic cells and scattered bright fine granules in the dermis, a suspicious palisading arrangement at the periphery, and there seemed to be peritumoral dark spaces. The combined dermoscopic and RCM examination were highly suspicious for the diagnosis of basal cell carcinoma (BCC), so the lesion was excised completely, but was eventually diagnosed as sebaceoma by histopathology. This case suggests that there are some overlaps in both dermoscopic and RCM features between sebaceoma and BCC. The application of dermoscopy and RCM to the diagnosis of sebaceoma is challenging, further studies are needed in this field.

Keywords: basal cell carcinoma; confocal microscopy; dermoscopy; sebaceoma.