Tehran University of Medical Sciences Acta Medica Iranica 0044-6025 55 4 2017 05 16 277 279 EN Mohammad Ali Mohagheghi Department of Surgical Oncology, Cancer Institute, Imam Khomeini Hospital Center, Tehran University of Medical Sciences, Tehran, Iran. Ramesh Omranipur Department of Surgical Oncology, Cancer Institute, Imam Khomeini Hospital Center, Tehran University of Medical Sciences, Tehran, Iran. Fereshteh Ensani Department of Pathology, Cancer Institute, Imam Khomeini Hospital Center, Tehran University of Medical Sciences, Tehran, Iran. Alireza Ghannadan Department of Pathology, Cancer Institute, Imam Khomeini Hospital Center, Tehran University of Medical Sciences, Tehran, Iran. Shahriar Shahriaran Department of Radiology, Cancer Institute, Imam Khomeini Hospital Center, Tehran University of Medical Sciences, Tehran, Iran. Farhad Samiee Radiation Oncology, Cancer Institute, Imam Khomeini Hospital Center, Tehran University of Medical Sciences, Tehran, Iran. Zahra Sedighi Cancer Research Center, Cancer Institute, Imam Khomeini Hospital Center, Tehran University of Medical Sciences, Tehran, Iran. 2015 10 12 2016 07 02 We present here a 32-year-old male with advanced lately diagnosed, right sided retroperitoneal mass, which had been already treated due to progressive muco-cutaneous lesions clinically consistent with psoriasis, during recent four years. The advanced retroperitoneal mass resected surgically and reported as hyaline-vascular castleman disease with a dense focus of coarse calcification, on histopathology. Association of psoriasis and castlman disease is discussed in this case report.  https://acta.tums.ac.ir/index.php/acta/article/view/4951 https://acta.tums.ac.ir/index.php/acta/article/download/4951/4930