Intramedullary enterogenous cyst of the conus medullaris presenting as lower limb pain

Abstract

Enterogenous cysts account for 0.7-1.3% of spinal axis tumors. Cervical and thoracic segments are most often affected and they are rare in the lumbar region. Intramedullary variant which comprises less than 5% of enterogenous cysts are densely adherent to the surrounding tissue and preclude total excision. Partial excision is associated with recurrence and is the most common unfavorable outcome in these cysts. Hence, such patients need follow-up with serial imaging. We describe a case of conus medullaris enterogenous cyst presenting as lower limb pain. Due to dense adhesion of the cyst to the surrounding neural tissue, subtotal excision was done. The patient is symptom and tumor free at one year interval. We describe our case, discuss its uniqueness and review the literature on this rare but difficult to cure tumor.

Keywords: Conus medullaris tumor; enterogenous cyst; intramedullary tumor; lower limb pain; neurenteric cyst.

Figure 1

Post contrast sagittal image of lumbo sacral spine showing a cystic lesion at D12-L1 level with enhancement of cyst wall

Figure 2

T2W sagittal image of spine showing a hyperintense cystic lesion at D12 – L1 level with hypointense cyst wall

Figure 3

Intra-operative image after performing laminectomy at D12- L1 level. The lesion appears predominantly cystic but the walls are densely adherent to the surrounding nerve rootlets

Figure 4

Histopathology image of cyst wall showing pseudostratified lining with goblet cells (a) and cilia (b)

Figure 5

One year post operative, post contrast sagittal image of lumbo sacral spine showing no residual or recurrent contrast enhancing tumor