Case of the Week
Section Editors: Matylda Machnowska1 and Anvita Pauranik2
1University of Toronto, Toronto, Ontario, Canada
2BC Children's Hospital, University of British Columbia, Vancouver, British Columbia, Canada
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August 17, 2015
Spinal Cystic Echinococcosis (Hydatid Disease)
- Background:
- Hydatid disease, or cystic echinococcosis, is a parasitic zoonosis caused by the larval stage of the cestode Echinococcus granulosus. It is rare even in areas where echinococcosis is endemic.
- Osseous hydatidosis constitutes only 0.5%–2% of all hydatidoses and the thoracic spine is the most common site of involvement.
- Clinical Features: Nonspecific and varied, depending essentially on the location and size of the cyst, as well as the degree of cord compression. Back pain is seen when there is bone erosion and spinal canal involvement.
- Key Diagnostic Features:
- CT shows a single or multiple multicystic osteolytic vertebral body lesions. CT myelogram helps to better demonstrate the cord compression.
- MRI shows the multicystic destructive bone lesion(s) resembling a "bunch of grapes". Typically, the lesion(s) will be well-defined, with nonenhancing thin-walled septae and no associated edema.
- As there is no pus, DWI will show no restricted diffusion.
- Cord compression will depend on the location and size of the lesion, as well as associated spine fracture/dislocation
- DDx:
- Tuberculosis (Pott disease)
- Neurocysticercosis
- Aneurysmal bone cysts
- Cystic metastasis
- Rx: Osseous hydatidosis must be treated surgically. It has an extremely high 1-year recurrence rate. Postoperative albendazole seems only to delay but not to prevent the recurrence