Primary Psoas Muscle Multiple Hydatid Cysts, Presenting as a Psoas Abscess: A Rare Case Report.

Hydatid disease is an anthropozoonosis, caused by the larval stage of parasitic tapeworm Echinococcus granulosus. Every organ of the human body can be affected by the Echinococcus granulosus but mostly the liver is involved. Hydatid disease of the muscles is not common, and the involvement of the psoas muscle is very rare. This is a case of a 45-year-old male presented to the emergency department with left flank pain, fever and left leg weakness since 6 months. A total of three hydatid cysts were found in the psoas muscle, extending to the left iliac fossa across the psoas muscle.