Desmoid Tumor of the Facet Joint: A Case Report
A 32-year-old man was admitted to our hospital for diagnosis and treatment of lower back pain, both buttock pain, and radiating pain in the left leg that were present for 1 month. He was a computer programmer who had experienced a traffic accident as a passenger 1 year ago, but he had no history of spine surgery. He had undergone nerve blocks several times for the treatment of pain. However, the treatment had had little effect.\nComputed tomography (CT) images of the lumbar spine showed a smooth, low-density area at the superior and inferior articular process of the left L3-4. Homogeneous enhancement was noted after contrast media injection, with pressure erosion of the facet joint and left lateral lamina (). On axial T1- and T2-weighted magnetic resonance imaging (MRI) scans, an intermediate-signal intensity mass of approximately 1.7×1.2×1.8 cm was seen in the left L3-4 paraspinal area. Strong enhancement was noted in the same region after contrast media injection ().\nThe patient underwent left L3-4 partial facetectomy without internal fixation and tumor removal under general anesthesia. In the operative field, a tumor, approximately 2.0×2.5 cm in size, with encapsulation was observed in the left L3-4 facet joint. The tumor was completely resected from its facet joint adhesions with a safety margin. The tumor was firm and yellowish-red in color ().\nHistology of the facet joint showed collagenous tissue infiltration and proliferation of apparently benign spindle cells separated by collagen that are characteristics of desmoid tumors. The histologic findings were typical of benign infiltrative fibromatosis, desmoid tumors ().\nFor 1 month, the patient performed rehabilitation exercises. Subsequently, his lower back pain, both buttock pain, and radiating pain in the left leg were significantly improved. Ten months after the operation, the patient had no neurologic deficit and no instability in following up radiography.