Intraosseous Epidermal Inclusion Cyst in the Distal Phalanx of Thumb with Cortical Destruction: A Case Report and Review of Literature

Park,  Jin Sung; Moon,  Dong Kyu; Park,  Hyung Bin; Cho,  Se Hyun

Case Report

Journal of the Korean Society for Surgery of the Hand 2011;16(3):179-184.
Published online September 30, 2011.

Intraosseous Epidermal Inclusion Cyst in the Distal Phalanx of Thumb with Cortical Destruction: A Case Report and Review of Literature

Jin Sung Park, Dong Kyu Moon, Hyung Bin Park, Se Hyun Cho

Department of Orthopedic Surgery, Gyeongsang National University School of Medicine, Jinju, Korea. jsparkler@naver.com

Received: 13 June 2011 • Revised: 24 August 2011 • Accepted: 30 August 2011

Abstract

Intraosseous epidermal inclusion cyst is a rare benign, cystic lesion. It is thought to result from traumatic implantation of epidermal elements into bone. Radiologic findings of intraosseous epidermal inclusion cysts are well-defined, lytic lesions. It is difficult to diagnose intraosseous epidermal inclusion cyst without pathologic diagnosis. We experienced a 43-year-old man with a history of trauma followed by painless expansion of his left thumb. Radiographs demonstrated a severe expansile, ill-defined lytic lesion with cortical destruction in the distal phalanx of left thumb, mimicking neoplastic bone lesion or infectious lesion. An intraosseous epidermal inclusion cyst was confirmed by pathologic diagnosis, which was lined by stratified squamous epithelium, containing keratinized cellular debris.