Intradural Extramedullary Bronchogenic Cyst: Clinical and Radiologic Characteristics, Surgical Outcomes, and Literature Review

An intradural extramedullary bronchogenic cyst (IEBC) is a congenital malformation and an extremely rare type of endodermal cyst. This study aims to report the clinical and radiologic characteristics and surgical outcomes of IEBCs and to review the available literature. The medical records of 6 patients (3 female) with pathologically confirmed bronchogenic cysts involving the spinal cord between 2009 and 2016 were retrospectively reviewed, and follow-up evaluations were performed. Of the 6 symptomatic lesions, 4 were located in the cervical vertebra, 1 at the lumbar vertebra, and the remaining 1 at the craniocervical junction. Radiographs showed signals similar to cerebral spinal fluid on all magnetic resonance imaging sequences without contrast enhancement. Total resection was achieved in 3 patients. Histopathology revealed simple and pseudostratified respiratory epithelium with benign subepithelial mucous glands and fat components neighboring the cyst. After a mean follow-up duration of 49.2 months, 2 asymptomatic residual lesions regrew after nontotal resection. In previous literature including 19 cases, most IEBCs (84.2%) tended to be homogeneous and well demarcated on radiologic images, and 85.7% were not contrast enhancing. Cervical or upper thoracic segments were predilection sites with intradural extramedullary localization. The majority of IEBCs had similar benign histological features. The recurrence rate was 15.4% after nontotal resection but nil after total resection. IEBCs displayed an indolent course, and the most effective management with positive outcomes was total resection. Nontotal resection, cystic fenestration, and biopsy, which were associated with recurrence, should be avoided.