A 61-year-old woman presented with low back pain associated with radiation to left lower limb since the past 1 year, with left foot drop since the past 1 month. Examination revealed wasting of the left lower limb with a foot drop. The remaining neurological examination was normal. Magnetic resonance imaging of the spine revealed diffusely bulky and multi-septated homogenous fluid-filled lesions (with signal intensity similar to cerebrospinal fluid [CSF]) in the intraspinal compartment from L3 to sacral vertebrae, causing extradural compression, and prevertebral and paravertebral locations (Figure 1). Contrast-enhanced computed tomography of the abdomen revealed similar cysts in the retroperitoneum, liver, and left psoas muscle. Serum ELISA was positive for Echinococcus IgG antibody (value-19.31; normal < 9), thus confirming the diagnosis of disseminated hydatidosis.
Hydatid disease is a parasitic infection caused by the larval form of Echinococcus granulosus. 1 Humans are intermediate hosts who become infected by accidental consumption of infected food/water, 2 with liver and lungs being the commonest sites of involvement. 3 Bone involvement is rare, occurring in less than 2% cases, with spinal involvement occurring in half of those cases. 3 The thoracolumbar spine is the common site of involvement, with involvement of the sacral spine being very rare. 4 ELISA serology has a sensitivity of 80–100% for hepatic infections but only 25–56% for other organ involvement. 5
In patients hailing from endemic regions and presenting with chronic low backache, with imaging suggestive of space-occupying lesions, hydatid disease should be considered in differential diagnosis. Early diagnosis and treatment lead to good clinical outcomes.
Khiari A , Fabre JM , Mzali R , Domergue J , Beyrouti MI , 1995. Unusual locations of hydatid cysts. Ann Gastroenterol Hepatol (Paris) 31: 295–305.
Agarwal S , Shah A , Kadhi SK , Rooney RJ , 1992. Hydatid bone disease of the pelvis. A report of two cases and review of the literature. Clin Orthop Relat Res 280: 251–255.
Segura-Trepicho M , Montoza-Nunez JM , Candela-Zaplana D , Herrero-Santacruz J , Pla-Mingorance F , 2016. Primary sacral hydatid cyst mimicking a neurogenic tumor in chronic low back pain: case report and review of literature. J Neurosci Rural Pract 7: S112–S116.
Karadereler S , Orakdögen M , Kiliç K , Ozdogan C , 2002. Primary spinal extradural hydatid cyst in a child: case report and review of the literature. Eur Spine J 11: 500–503.