Histopathological findings of hemorrhagic ganglion cyst causing acute radicular pain: a case report.

Although juxtafacet cysts of the lumbar spine are being reported with increasing frequency, hemorrhage from a ganglion cyst is rare, and the pathophysiologic mechanism of the hemorrhage from the cyst is still unclear. A 75-year-old male presented with sudden radicular leg pain caused by hemorrhage from the ganglion cyst. Computed tomography revealed bony erosion of vertebral body and multiple punched-out lesions on facets. Magnetic resonance imaging showed the neural structure was compressed by a sharply delineating mass. Capsule and old hematoma with elastic consistency that extended to the epidural space were removed through a paramedian transforaminal approach, which led to the resolution of the patient's symptoms. Histopathologically, chronic inflammation with neovascularization and myxoid degeneration were present in the capsule. Alcian blue staining demonstrated the mixture of mucin and hematoma. The probable pathogenesis of hemorrhage from the cyst was discussed from the unique histopathological findings of surgical specimen.