In vivo Confocal Imaging of Pigmented Eccrine Poroma

Background: Near-infrared reflectance confocal microscopy (CM) imaging is a noninvasive technique that can be utilized to evaluate histologic features of cutaneous lesions in vivo. Objective: A case of pigmented eccrine poroma was examined with CM. Methods: Confocal images were taken to define the features of the lesion and correlated with transverse hematoxylin-eosin (HE)-stained sections. Results: In CM imaging, a well-demarcated homogeneous nest consisting of small uniform cells was seen. The nest contained nonrefractile dark spaces that may represent cuticuli. Many dendritic melanocytes containing melanin were intermingled with the tumor cells, and numerous melanophages were present in the upper dermis. A marked prominence of surrounding vessels was also demonstrated. Conclusions: CM could well demonstrate the features of a pigmented eccrine poroma, as correlated with transverse HE-stained sections. However, high reflectance signals from melanin had to be carefully considered before a definitive diagnosis could be made.