Dumbell hydatid disease of spine with posterior paraspinal muscle involvement

Abstract Spinal hydatid disease is a rare form of hydatid disease caused by the larval form of Echinococcus granulosus (E. granulosus). Dogs are primarily the definitive hosts of E. granulosus with man and sheep serving as intermediate hosts. Spinal HD contributes to approximately 45 % of all skeletal hydatid disease cases. Spinal HD is perhaps the worst form of parasitic infestations associated with morbidity requiring surgical correction. Braithwaite and Lees have classified spinal hydatids into five types (1) intramedullary (2) intradural extramedullary (3) extradural intraspinal disease (4) vertebral hydatid (5) paravertebral hydatid. When hydatid disease from spinal canal extends into retroperitoneal space through the neural foramen, it gives dumbell formation (similar to nerve sheath tumors). Symptoms of hydatid are mainly due to compressive effects of the cyst, low back pain accompanying motor weakness, sensory disturbances, bowel and bladder disturbances and cauda equina syndrome. Extensive vertebral hydatidosis can cause fractures of vertebrae. Serology tests are used in diagnosing suspected cases of hydatid disease. MRI with soft tissue detail is more preferable than other modalities in diagnosing spinal hydatid. Successful treatment of spinal hydatid disease necessitates adequate neuroimaging evaluation, careful surgical removal without spillage of cystic components and adding adjuvant chemotherapy in few cases is the mainstay of treatment. Sometimes when it is difficult to retrieve all the cysts in toto, debulking is advised.