Tehran University of Medical Sciences Case Reports in Clinical Practice 2538-2683 2 4 2018 05 14 116 119 EN Safoura Shakoei Assistant Professor, Department of Dermatology, Imam Khomeini Hospital, Tehran University of Medical Sciences, Tehran, Iran. Maryam Nasimi Assistant Professor, Department of Dermatology, Razi Hospital, Tehran University of Medical Sciences, Tehran, Iran. Alireza Ghanadan Associate Professor, Department of Dermopathology, Razi Hospital AND Department of Pathology, Cancer Institute, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran. Sirous Jafari Associate Professor, Department of Infectious Disease, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran. Arghavan Azizpour Assistant Professor, Department of Dermatology, Razi Hospital, Tehran University of Medical Sciences, Tehran, Iran. 2017 12 23 2018 02 18 Cutaneous squamous cell carcinoma (cSCC), which is the second most common malignancy in humans, commonly occurs on sun-exposed skin such as face. Incidence rate of squamous cell carcinoma is found to be higher in old men. Metastatic rate of cutaneous squamous cell carcinoma is approximately 4-5%, and it is higher in men, especially those over the age of 75 years. Risk factors that increase the rate of metastatic SCC include immunosuppression like human immunodeficiency virus (HIV), solid organ transplantation, tumor thickness (> 2 mm), lesion diameter (> than 2 cm), poor differentiation, and perineural invasion. To our knowledge, our case is the first report of squamous cell carcinoma with large size with bilateral lesion extending from the groin to intergluteal region. https://crcp.tums.ac.ir/index.php/crcp/article/view/165 https://crcp.tums.ac.ir/index.php/crcp/article/download/165/94