Symptomatic Lumbar Discal Cyst: A Rare Entity that Can Mimic Other Lumbar Cystic Lesions.

Lumbar discal cyst (LDC) is a rare clinical entity with unclear etiology. Three theories have been proposed to describe the pathogenesis of this condition: (i) a reaction to spinal epidural hematoma; (ii) a pseudomembrane formation that follows the focal annular tear and disc degeneration; and (iii) an inflammatory reaction to the herniated disc fragment. It usually presents with radicular symptoms. Radiographically, LDC can mimic other cystic lesions of the lumbar spine. Imaging nuances such as scalloping of the vertebral body, contrast filling with discography, and MRI signal intensity on different sequences can help to establish a diagnosis of LDC. However, there are no clear guidelines on the best treatment approach. Several treatment options have been prescribed to treat LDC with good outcomes. Here we describe a case of LDC that presented with left-sided radicular symptoms for several months and had not undergone any initial conservative management. The patient was treated successfully with microscopic resection of the cyst with complete resolution of the symptoms.