[Symptomatic intramedullary arachnoid cyst. Report of two cases and literature review].

OBJECTIVE The objective of this work is to present and discuss the rare situation of curable medullary compression with favorable prognosis. MATERIAL AND METHOD Two cases of thoracic intramedullary arachnoid cysts are described. Clinical, paraclinical, therapeutics and outcome features are discussed with a review of the literature. RESULTS Two children, 4 and 8 years old, with an uneventful history were admitted for progressive spastic paraparesia. MRI demonstrated a thoracic intramedullary cystic lesion at level T3-T4 in both patients. The cyst was emptied with partial cyst wall resection via dorsomedial myelotomy. The pathology examination confirmed the diagnosis of arachnoid cyst. The initial clinical signs resolved completely in both patients. CONCLUSION Thought in children, intramedullary arachnoidian cyst is a potential cause of medullary compression. Direct surgery is the treatment of choice.