Isolate metastasis of listhetic vertebra

OBJECTIVE: To document the case of isolated metastasis in an isthmic spondylolisthesis in the adult. SUMMARY OF BACKGROUND DATA: The progression of isthmic spondylolisthesis occurs infrequently in the adult. Previous reports have pointed out the pathogenic responsibility of the progressive disc collapse. METHODS: A 58-year-old woman was evaluated for severe back and bilateral leg pain. Standing radiographs of her lumbar spine showed L5-S1 spondylolisthesis. CT and MRI scans demonstrated a tumor infiltration of the L5 listhetic vertebra. RESULTS: Bilateral interruption of the posterior arch was noted at surgery. A posterior decompression with an L3-S1 pedicle screw fixation was performed without complication. Leg pain and paraparesis promptly regressed. A solitary localization of an undifferentiated adenocarcinoma of unknown origin was diagnosed. The patient refused further surgery and died three years after the operation. CONCLUSIONS: The progression of isthmic spondylolisthesis occurs infrequently in the adult. This case shows that tumor infiltration is a potential cause for the onset/progression of spondylolisthesis in the adult. An MRI or CT scan of the spine is recommended in skeletally mature patients with isthmic spondylolisthesis who sustain severe and acute exacerbation of their back pain.