[An adolescent with lumbosacral instability due to the presence of a hydatid cyst: a case report].

Hydatidosis, caused by Echinococcus granulosus, affects the spinal column in 0.5-2% of all cases, with the sacral column being a rare location typically observed only in adults. The case is reported of a 14-year-old boy from Juliaca (Puno, Peru) who presented with chronic lower back pain and cauda equina syndrome. He was initially attended to in Juliaca, and then transferred to the Hospital Edgardo Rebagliati Martins (Lima, Peru) with a diagnosis of sacral tumor. In magnetic resonance imaging, a multicystic tumor was seen with L5 and S1 lysis and instability. The surgical treatment was an L5- S2 laminectomy and extraction of multiple hydatid cysts followed by lumbopelvic stabilization with transpedicular screws. Post-operatively, he was prescribed albendazol (15 mg/kg/d) for six months. Hydatid cysts should be considered within the differential diagnosis when there are cystic lesions in the spinal column, particularly in endemic areas such as Peru.