Alveolar echinococcosis of the spine

Alveolar echinococcosis (AE) is a rare parasitic disease caused by the larv al stage of Echinococcus multilocularis. It differs from cystic echinococco sis caused by Echinococcus granulosus. The main endemic areas of AE are Ala ska, Canada, Japan, and parts of Europe. Hepatic involvement invariably occ urs, but it is unusual for bone to be affected. We report the case of a wom an presenting with a long history of pain, cachexia, morning stiffness, and biological signs of inflammation. Radiographs and principally magnetic res onance images were nonspecific, showing inhomogeneous osteolysis of vertebr al bodies without loss of intervertebral disc height but with a paravertebr al mass. The diagnosis ultimately relied on pathological examination, which showed an anhistic laminated membrane colored in red with Periodic-Acid-Sc hiff surrounding a central cavity, and by the serologic testing, principall y ELISA Em2+ method, which allowed a 97% specificity and 99% specificity in the diagnosis of AE. AE involving bone is an uncommon condition. Although magnetic resonance ima ging can be used to search for local complications, the features it detects are, like those revealed by radiographs, nonspecific and can, lead to A-E being misdiagnosed as neoplasm or tuberculous osteitis. When a patient pres ents with suspected AE in an endemic area, the diagnosis can be achieved by serological testing alone (Western blot and Em2+ ELISA), thereby avoiding the need for biopsy.