ABSTRACT
Hydatid disease is a zoonotic infection caused by Echinoccosis granulosus and our country was an endemic area. Osseous localization is uncommon and can be confused with tumor. We present a case of a hydatid cyst with rib involvement in a 57-year-old man presented with thoracic pain and swelling mimicking chest wall tumor. We confirmed diagnosis only by surgical exploration and histopathology exam because radiology is not conclusive. Surgery remains the first choice for treatment in hydatid cyst disease that can remove the parasite radically. However, in osseous localization pre and postoperative course of albendazole for 6 months associated with surgery can help in sterilizing the cyst and reduce the recurrence rate. Hydatid cyst can involve all the thoracic structures; rib localization is rare and needs surgical resection for total eradication.