p16INK4a Expression in Porokeratosis

Vol. 29, No. 3, 2017 373 Received February 5, 2016, Revised May 16, 2016, Accepted for publication June 27, 2016 Corresponding author: Masutaka Furue, Department of Dermatology, Graduate School of Medical Sciences, Kyushu University, Maidashi 3-1-1, Higashiku, Fukuoka 812-8582, Japan. Tel: 81-92-642-5581, Fax: 81-92-642-5600, E-mail: [email protected] This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/ licenses/by-nc/4.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Copyright © The Korean Dermatological Association and The Korean Society for Investigative Dermatology Bcl-2, and stromal cells next to tumor cells stain positive for CD34. Moreover, Ki-67, a proliferative marker associated with mitosis, shows relatively weak nuclear positivity. These features help differentiate BFH from basal cell carcinoma, especially infundibulocystic type, in that this presents with deeper infiltration, strong nuclear positivity for Ki-67, negativity for CD34, and prominent cytoplasmic positivity for Bcl-2. Other differential diagnoses include trichoepithelioma, which shows more abundant and highly fibrocytic stroma, and frequently involves follicular bulbs and papillae. In conclusion, we report a case of BFH with clinical presentation of localized grouped papules on the chest of an adult that has not been reported.