Direct rupture of splenic hydatid cyst without volume loss: report of a unique case.

We present a rare case of primary spleen Echinococcus cyst with rupture evidence due to trauma. The cyst presented with an echogenic pattern at ultrasound examination but subsequent CT study revealed calcification of the cyst wall and signs of rupture. Serological tests were positive for echinococcus and eosinophilia defined. Volume changes of hydatid cyst were not discernible in the imaging studies despite evidence of rupture. Both imaging methods may suggest the diagnosis unless typical diagnostic features are present. Hydatid disease was confirmed histologically on the specimen after surgical excision of the cyst.