Primary hydatid cyst in the temporal region.

DESCRIPTION Hydatid disease is an important infestation caused by the parasite Echinococcus granulosus. The liver is the most frequently involved organ (75%), followed by the lungs (15%) and the remainder of the body (10%). We present a rarecaseofsubcutaneoushydatidcystinthetemporalregion, whereasmallcysthadbeenpresentfor theprevious50years. ThepatientwasanelderlywomanfromGreecewithagradually enlarging mass in the left temporal fossa. During preoperative preparation, the skin covering the mass spontaneously ruptured, revealing a large cyst (figure1) and more than 20 smaller cysts. The cysts were displacing the superficial muscles of the left temporal region and eroding the bone. The diagnosis was confirmed by H&E staining and treatment with albendazole was started on clinical suspicion immediately after surgery. Serological tests (direct haemagglutination) were negative and the patient had no anaphylactic reaction during her stay in hospital. Hydatid cysts located in the head and neck region are extremely rare, even in areas where echinococcal infestation is frequent. 2 Passage through the hepatic sinusoids and dissemination through the lymphatic channels of the intestine are possible routes for cases with primary hydatidosis in uncommon sites. Medical imaging such as CT or ultrasonography are important tools in diagnosing infestation caused by E granulosus. Hydatidosis should be considered in the differential diagnosis of superficial subcutaneous cystic lesions.