Primary paraspinal lumbar hydatid disease: A known diagnosis in an unusual localization.

Hydatid disease is a parasitic infection caused by Echinococcus granulosus. Although the liver and lung are the most common sites of hydatid disease, it can also be seen in other organs due to migration via systemic circulation. Paraspinal lumbar hydatid disease without the involvement of other organs is extremely rare. We aimed to present the imaging and histopathological findings of a case with painful lumbar swelling that was later diagnosed as primary lumbar paraspinal hydatid disease. Hydatid disease should be considered as the differential diagnosis in patients with a lumbar paraspinal mass, particularly that containing multiple well-defined, round, small cysts, and in patients living in or traveling to endemic regions.