Primary diagnosis of soft tissue echinococcosis by aspiration cytology

A case of hydatid cyst of soft tissue diagnosed by Fine needle aspiration of a cyst is reported. The patient presented with gradually increasing swelling in the anterior-inferior aspect of shoulder. The provisional clinical diagnosis of cold-abscess shoulder was made, patient was referred for Fine needle aspiration cytology (F.N.A.C.). Swelling was aspirated by 23-gauge needle obtaining 1.5 ml of blood-mixed fluid. Smears of fluid showed protoscolices, fully developed scolices with rostellum and scattered hooklets, pathognomonic of Echinococcosis. Histopathologic examination of surgically removed cyst showed chronically inflamed echinococcal cyst. No complication was observed.