Lymphoma Metastasis to Vertebral Body Hemangioma: Collision Tumor Causing Cord Compression

Collision tumors of the spine are extremely uncommon. Prior reports have detailed intracranial collision tumors comprising meningiomas and astrocytomas, as well as metastases to meningiomas. Spinal collision tumors are even rarer, with only 5 cases in the literature, none involving the osseous spine. In this report, we highlight the salient features of a case of lymphoma metastasis to a preexisting benign osseous hemangioma, resulting in cord compression. An 81-year-old woman with a known typical T8 vertebral body hemangioma stable for over 6 years was evaluated for increasing back pain, new gait instability, and urinary retention. Magnetic resonance imaging showed a change in the appearance of the T8 hemangioma, with marrow replacement and new associated epidural soft tissue causing cord compression. A biopsy was performed, which showed diffuse large B-cell lymphoma within blood elements, consistent with lymphoma metastasis to a vertebral body hemangioma. The patient was treated with intravenous steroids and radiation therapy. Collision tumors of the spine are extremely rare. New or increasingly aggressive appearance of a previously benign spinal osseous lesion should prompt consideration for a collision tumor or malignant transformation of the benign tumor. Biopsy of the lesion should be strongly pursued whenever feasible, as the treatment strategy may vary depending on the histology of the tumor.