A rare, incidental submandibular hydatid cyst.

Hydatid cyst disease is a parasitic infestation caused by Echinococcus granulosus. It is transmitted via oral ingestion of eggs excreted by dog's stool. Liver and lungs are the most commonly involved organs. Primary involvement of submandibular region by hydatid cyst is extremely rare. In this article, we report a case of a lesion excised from submandibular region with an initial diagnosis of branchial cleft cyst, but shown to be a hydatid cyst in histopathological evaluation.