Tehran University of Medical Sciences (TUMS) Academic Journal of Surgery 2423-3218 4 3 2017 12 29 87 89 EN Nasser Malekpour-Alamdari Assistant Professor, Department of Surgery, School of Medicine AND Shahid Modarres Medical Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran Barmak Gholizadeh Assistant Professor, Department of Surgery, School of Medicine AND Shahid Modarres Medical Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran Fereshteh Kimia Resident, Department of Anesthesiology, School of Medicine AND Shahid Modarres Medical Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran 2017 07 20 2017 12 29 Background: Hydatidosis is a parasitic infestation caused by Echinococcus granulosus. This tapeworm commonly affects liver and lungs. Its diagnosis in unusual locations may be make some challenges for practicing physicians. Case Report: A 45-year-old man presented with bulging and discomfort in the right lower quadrant from 2 years ago. Computed tomographic examination showed an oval cyst measuring about 7 cm × 15 cm in the inguinal area. In the operating room, after sealing the area with appropriate amounts of gauze soaked in silver nitrate the cyst punctured and clear fluid aspirated from the cyst; then, the cyst was sterilized using silver nitrate and opened. Daughter cysts were extracted from the cyst, the cyst was carefully freed from surrounding structures, and total excision of the cyst was performed. Post-operative period was uneventful, and no recurrence was encountered during the 6-month follow-up period. Conclusions: In this case, we present a patient with swelling in the inguinal area, which turns out to be hydatid cyst. To our knowledge, there has been no case of hydatid cyst arising primarily from inguinal canal. Hydatid disease can present with many different symptoms, and in this case, we present one the rare presentations of this disease. So that for a surgeon who works in the endemic areas, it is important to be aware about the varying presentations of the disease so that in the operation room should do required preparations to prevent unwanted serious problems such as spillage of intracystic materials. https://ajs.tums.ac.ir/index.php/ajs/article/view/103 https://ajs.tums.ac.ir/index.php/ajs/article/download/103/76