Juxtafacet cyst pathology
Cyst walls are composed of fibrous connective tissue of varying thickness and cellularity. There are usually no signs of infection or inflammation. There may be a synovial lining 1) (synovial cyst) or it may be absent 2) (ganglion cyst). The distinction between the two may be difficult, 3) possibly owing in part to the fact that fibroblasts in ganglion cysts may form an incomplete synovial-like lining 4). Proliferation of small venules is seen in the connective tissue. Hemosiderin staining may be present, and may or may not be associated with a history of trauma 5).
Lumbar juxtafacet cyst arise from the zygapophyseal joints of the lumbar spine and commonly demonstrate synovial herniation with mucinous degeneration of the facet joint capsule 6).