Dual lumbar bronchogenic and arachnoid cyst presenting with sciatica and left foot drop

Spinal bronchogenic cysts are rare findings, with only four cases of lumbar bronchogenic cysts reported in the literature. All of these bronchogenic cysts involved the conus medullaris. We present the first case of a lumbar bronchogenic cyst and arachnoid cyst arising from the cauda equina in a 68-year-old male. Uniquely, this bronchogenic cyst also contained components of an arachnoid cyst.

Magnetic resonance imaging (MRI) demonstrated a compressive cystic lesion at the level of the L3 vertebra splaying the cauda equina. An L3/L4 laminectomy was performed with marsupialisation of the cyst.

Histological examination revealed pseudostratified ciliated columnar epithelium confirming the diagnosis of a bronchogenic cyst, as well as a pleated fibrovascular tissue lined by sparsely spaced small monomorphic arachnoidal cells, indicating an arachnoid cyst.

We demonstrate that bronchogenic cysts can be successfully treated with marsupialisation.