-Case Reports-

A Case of Infundibulocystic Basal Cell Carcinoma Clinically Mimicking a Melanocytic Nevus Associated with Epidermal Cysts

Yushi Kawasaki¹, Shinn-ichi Ansai², Kazuhisa Fujimoto³, Hidehisa Saeki³ and Seiji Kawana³

¹Department of Dermatology, Nippon Medical School Chiba Hokusoh Hospital, Chiba, Japan
²Department of Dermatology, Nippon Medical School Musashi Kosugi Hospital, Kanagawa, Japan
³Department of Dermatology, Nippon Medical School, Tokyo, Japan

A 52-year-old Japanese woman presented with a 1.5-cm black, glossy, flat, pediculated lump that clinically mimicked a melanocytic nevus on the left temporal side of her head. The subcutaneous tumor beneath the nodule was elastic and hard. A histological examination showed that the tumor was well circumscribed with an exo- and endophytic growth 2.4 × 1.9 cm in size. The lesion contained several keratinous cysts and was composed of funicular fascicles containing squamoid cells. Excessive mucinous material deposition was observed around the tumor periphery and a palisading arrangement of nuclei in the tumor periphery was seen in some areas. Based on these findings, a diagnosis of infundibulocystic basal cell carcinoma (IFC-BCC) was made. This report presents a case of IFC-BCC that clinically mimicked a melanocytic nevus and was also associated with epidermal cysts.

J Nippon Med Sch 2018; 85: 228-230

Keywords
follicular differentiation, funicular fascicles, infundibulocystic basal cell carcinoma, melanocytic nevus-like appearance, squamoid cells

Correspondence to
Yushi Kawasaki, MD, PhD, Department of Dermatology, Nippon Medical School Chiba Hokusoh Hospital, 1715 Kamagari, Inzai, Chiba 270-1694, Japan
yushikawasaki@hotmail.com

Received, January 29, 2018
Accepted, February 6, 2018