en Surgery Surgery case report case report <span style="font-size:14px;"><span style="font-family:Times New Roman;"><span style="line-height:14pt"><b><i><span style="color:blue">Background:</span></i></b> Echinococcus granulosus causes hydatid disease, which is found in various countries of the world, including Iran. The liver and lungs are prevalent involved structures in hydatid disease. One of the least common sites in hydatid disease seems to be the omentum. Seven cases of mesenteric, diaphragmatic, omental, pelvic, and retroperitoneal hydatid cysts have been reported in Iran within last 20 years. The appearance of hydatid disease as a primary mass in the greater omentum without hepatic involvement is very rare and no similar case was introduced in Iran in our searches.</span><br> <span style="line-height:14pt"><b><i><span style="color:blue">Case Presentation:</span></i></b> Our patient was a 33-year-old woman who underwent a diagnostic laparoscopy due to abdominal pain and an abdominal mass. During laparoscopy, there was a solid mass with a size of about 10 &times; 5 cm in the greater omentum that was resected. The histopathological examination of the mass showed the hydatid disease.</span><br> <span style="line-height:14pt"><b><i><span style="color:blue">Conclusion:</span></i></b><b> </b>The hydatid cyst can appear anywhere on the body, and no part of the body is guarded. Since these uncommon locations often cause nonspecific symptoms, the hydatid cyst should be included in the differential diagnosing of omental cysts, particularly in endemic countries like Iran.<b><i><span style="color:#0033cc"></span></i></b></span></span></span> Hydatid disease, Hydatid Cyst, Echinococcus Granulosus, Greater Omentum, Echinococcosis, Case Report 386 390 http://caspjim.com/browse.php?a_code=A-10-2181-3&slc_lang=en&sid=1 Ali Jangjoo jangjooa@mums.ac.ir 100319475328460041911 100319475328460041911 No Surgical Oncology Research Center, Mashhad University of Medical Sciences, Mashhad, Iran Sina Norouzi Asl sinanorouzi1362@gmail.com 100319475328460041912 100319475328460041912 No Surgical Oncology Research Center, Mashhad University of Medical Sciences, Mashhad, Iran Yeganeh Azadmanesh yeganeh_60222@yahoo.com 100319475328460041913 100319475328460041913 No Department of Emergency Medicine, Razavi Hospital, Mashhad, Iran Tooraj Zandbaf tooraj.zandbaf@gmail.com 100319475328460041914 100319475328460041914 Yes Department of General Surgery, Faculty of Medicine, Mashhad Medical Sciences, Islamic Azad University, Mashhad, Iran