ePlasty: Vol. 19
Squamous Cell Carcinoma Arising From an Epidermal Cyst of the Buttock: A Case Report
Michika Fukui, MD, Natsuko Kakudo, MD, PhD, Naoki Morimoto, MD, PhD, Masakatsu Hihara, MD, Hiromu Masuoka, MD, and Kenji Kusumoto, MD, PhD

Department of Plastic and Reconstructive Surgery, Kansai Medical University, Osaka, Japan

Correspondence: kakudon@hirakata.kmu.ac.jp
Keywords: squamous cell carcinoma, epidermal cyst, malignant transformation, large and long-standing tumor, rapid growth


A 70-year-old man presented with a mass on his right buttock, which measured 7 × 7 cm in diameter (Fig 1), and a swelled right inguinal lymph node. He noticed the mass 20 years ago. It was infected and discharged pus, and recently it has been growing rapidly. Antibiotics were ineffective. Magnetic resonance imaging showed that it had invaded the subcutaneous region (Figs 2a-2d). We excised it with a 3-cm surgical margin and the muscle fascia, as well as the swelled lymph node (Figs 3a and 3b). Histopathologically, this case was diagnosed as a squamous cell carcinoma arising from an epidermal cyst and right inguinal lymph node metastasis, because the epithelium of the squamous cell carcinoma was contiguous with the epithelium of th .......