Background: Hydatid disease is a parasitic infestation of the humans that caused by echinococcus granulosus and can produce tissue cyst everywhere in body. The most common locations for development of a parasitic cyst are the liver (75%) and the lung (15%). Skeletal involvement in eccinococcal infection is a relatively rare condition and is seen in only 1-4% of cases and few reports from the medical literature have presented rib hydatidosis which clinically mimics benign or malignant cystic tumors at initial presentation and because of its unusual presentation, its diagnosis may easily be missed.
Case presentation:A 19-year-old Iranian male patient presented with a 7-month history of a painful chest wall mass. Computed tomography and chest X-Ray showed a mediastinal and chest wall mass with rib erosion. The surgery allowed both diagnosis and treatment. The patient underwent a right posterolateral thoracotomy. Daughter cysts were seen when the lesion was incidentally opened. Cystic portion of mediastinal and chest wall mass and involved rib was resected. The mass histologically diagnosed as hydatid cyst. Albendazol (800mg daily) was administered for three months postoperatively. The patient was discharged at postoperative 5th day in a state of complete recovery. Follow up at 1 year postoperatively demonstrated no recurrence of the chest wall mass.
Conclusion:Primary chest wall hydatid cyst is an extremely unusual condition and should be included in the differential diagnosis of chest wall masses especially in endemic areas.