Rare Thymoma Metastases to the Spine: Case Reports and Review of the Literature

Background We report a series of 3 cases of metastatic thymoma to the spine with spinal cord compression. An extensive literature review of thymic metastases to the spine was completed to provide a comprehensive appraisal of current prognostic indicators and potential treatment algorithms to help guide clinicians in treatment management. Case Descriptions Between 2000 and 2017, 3 patients received diagnoses of thymic metastases to the spine at our institution. Metastasis presentation occurred from 2 to 8 years after the initial diagnosis with thymic cancer. All 3 patients presented with signs and symptoms of spinal cord/cauda equina compression, and underwent surgical intervention. Postoperative treatments varied among all 3 patients, 1 receiving chemotherapy, another undergoing radiation, and the third having had no further treatment because of extensive systemic disease. Conclusions Upon review of the literature, 16 case reports/series described 28 total patients with spine metastases secondary to thymoma/thymic carcinoma. The presentations varied widely, including age, neurologic deficits, time from initial diagnosis to metastasis, and histologic grading. The only widely accepted prognostic factor is completeness of tumor resection, whereas clinical staging, histologic type, or both may also have prognostic value. Thus, gross total resection and spinal decompression should be prioritized in cases of surgical intervention. Chemotherapy and radiotherapy are generally recommended. However, given the lack of standardized treatment algorithms, individualized regimens should be formulated on a case-specific basis.