Quiste aracnoide espinal: presentacion de un caso / Spinal arachnoidal cyst: case presentation

RESUMEN

Objective: to present a case of an extradural arachnoid dorsal cyst in a 30 year-old woman. Description a patient (30 years, female) who refers eight-months history of radicular pain and progressive right leg weakness, with exacerbations and remissions. On examination the patient had righ hemihypesthesia with T-10 sensitive level and right leg 4/5 palsy. Magnetic resonance imaging showed an extradural cystic lesion in T11-T12 hypointense in T1 and hyperintense en T2, without contrast enhancement. The cyst contained fluid tha demonstrated the same signal as cerebrospinal fluid. Intervention After laminectomy of T-10 and T-11 the cystic lesion was exposed. The cyst was filled with CSF-fluid like. A surgical resection of the cyst wall was made. A small dural defect that allowed communication between the cyst and the subarachnoid space was revealed during the surgery, and a closure was made with a suture. Histopathological examination confirmed a cystic lesion with a single-cell lining of meningothelial cells, that contained no neural tissue neither ganglion cells. Conclusion: extradural arachnoid cysts showed characteristic images in the MRI in the preoperative stage. There was no need to use other invasive methods such as myelography or mielotomography to decide the indication for surgery or the surgical technique. Definitive diagnosis is based on the free comunication with the subarachnoidal space and the lack of neural tissue in the histopatological examination, which allowed us to distinguish between extradural arachnoid cysts and Tarlov cysts