Related Experiment Video
Updated: Mar 19, 2026

Combining Reflectance Confocal Microscopy with Optical Coherence Tomography for Noninvasive Diagnosis of Skin Cancers via Image Acquisition
Published on: August 18, 2022
Basal Cell Carcinoma or Trichoblastoma? Dermoscopic Examination of Black Macules Developing in the Same Nevus
Shinya Kitamura1, Hiroo Hata1, Keisuke Imafuku1
1Department of Dermatology, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
Abstract:
Nevus sebaceus (NS) is a common congenital birthmark, and various tumors have been reported to develop in NS. Basal cell carcinoma (BCC) seldom occurs in NS, and it is very important to be able to clinicopathologically distinguish BCC from trichoblastoma. Herein, we describe a case of BCC and trichoblastoma occurring simultaneously in the same NS, including the differential dermoscopic features. BCC is clinically difficult to distinguish from trichoblastoma because the clinical manifestations are similar. In a dermoscopic examination of BCC, arborizing vessels are one of the diagnostically significant features. In our case, the BCC showed 'multiple' black structures, and the trichoblastoma showed a 'single' black structure without arborizing vessels. To the best of our knowledge, there have been no reports on the dermoscopic findings of secondary tumors on NS.
Related Concept Videos
Skin Cancer
Basal Cell Carcinoma (BCC): BCC is the most common type of skin cancer, accounting for about 80% of cases. It typically develops in...
Papillary Dermis
The dermis might be considered the "core" of the integumentary system, as distinct from the epidermis and hypodermis. It contains blood and lymph vessels, nerves, and other structures, such as hair follicles and sweat glands. The dermis is made of two layers of connective tissue that comprise an interconnected mesh of elastin and collagenous fibers, produced by fibroblasts.
Papillary Layer
The papillary layer is made of loose, areolar connective tissue, which means the collagen...

