Case reportThymoma metastatic to the extradural spine
Introduction
Spinal epidural metastasis is the most common spinal tumor, occurring in approximately 10% of all cancer patients.[1], [2] Lung, breast, gastrointestinal and prostate cancer, as well as melanoma and lymphoma are the primary sites accounting for 80% of metastases.3 Most cause bony destruction, although metastatic prostate and breast cancer may cause osteoblastic changes. The most common route of metastasis is hematogenous spread to the vertebral body with erosion posteriorly through the pedicles and into the epidural space. The thoracic spine is the site of 50–60% of epidural metastases. Less than 5% of metastases are intradural or intramedullary.2
Malignant thymoma is a rare, slow-growing, anterior mediastinal tumor. Local invasion and intrathoracic spread are relatively common, and extrathoracic metastases are present in up to 15% of patients, often in the liver, kidney, and bone.4 Approximately one-third of patients with thymoma have myasthenia gravis. Invasive thymomas with a larger component of epithelial cells and association with myasthenia gravis have a poor prognosis.5
The authors describe an unusual case of a 45-year old man with a past history of thymoma presenting twelve years after primary diagnosis with back pain and sensory neuropathy. Review of the literature reveals only a few where thymoma is documented to metastasize to the extradural spine.[4], [5], [6], [7], [8], [9], [10], [11], [12], [13] This case is interesting as the symptoms presented twelve years after primary diagnosis. We also comment on the novel surgical approach of spondylectomy and anterolateral decompression for tumor resection.
Section snippets
Case report
A 45-year old male was referred to the Neurosurgery Clinic in 2002. He complained of progressive back pain and decreased sensation in his toes bilaterally for several weeks. He denied trauma. He had been diagnosed with thymoma in 1990 after presenting with dyspnea. He was subsequently treated with chemotherapy, thymectomy, and local radiotherapy. His course was complicated by hemidiaphragm paralysis. In 1992, he developed myasthenia gravis, for which he was treated with gamma-globulin. He was
Discussion
Spinal extradural metastases are diagnosed preoperatively by radiological studies and clinical examination findings. On MRI, vertebral metastases are usually hypointense compared to normal bone marrow on T1-weighted images and hyperintense on T2-weighted images. Involvement of the posterior vertebral body and pedicle may be apparent on axial views. Pain is the most common presenting symptom, particularly exacerbated by movement, recumbency or straining. Up to two-thirds of patients with spinal
Conclusion
Spinal epidural metastases should be suspected in any cancer patient with back pain that persists in recumbency, even if the patient has been treated with systemic chemotherapy for the primary neoplasm and is believed to be free of disease for a prolonged period of time. Although thymoma is usually a benign tumor, it can be malignant, and therefore should be considered in the differential diagnosis of spinal cord lesions in patients with primary thymoma. Prognostic factors particular to the
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Cited by (10)
Treatment strategy and prognostic analysis of spinal metastases from thymomas: A retrospective study from a single center
2020, Clinical Neurology and NeurosurgeryCitation Excerpt :Radiological studies (X-ray, CT, MRI, bone scan and PET/CT) are largely nonspecific, making it a daunting challenge to distinguish metastatic spinal thymoma from other metastatic lesions [21–24]. In practice, radiology studies play an important role in the decision-making process for selecting surgical intervention [21–24]. The “gold standard” diagnostic approach for metastatic spinal thymoma depends on the pathology results [14,15,25].
Rare Thymoma Metastases to the Spine: Case Reports and Review of the Literature
2018, World NeurosurgeryCitation Excerpt :The median time to spinal metastases after initial presentation was 5 years (range, 0 discovered at initial presentation to 24 years after primary tumor resection). Whereas approximately half of patients described back pain, neck pain, or both at presentation, symptoms included hoarseness, dysphagia, or both for a C3–C4 lesion,25 paresthesias,22,26 sensory change,19 numbness,18,21 weakness, and paraparesis/paralysis.15,16,21,22,28 There was distinct variability in metastatic tumor presentation according to the WHO pathologic classification.
Thymic carcinoma with primary spine metastasis
2011, Journal of Clinical NeuroscienceCitation Excerpt :Spinal metastasis is very rare. To our knowledge, only two patients with spinal metastasis from TC have been reported.3,7 Owing to the paucity of these patients, there are still no defined treatment protocol for TC.6
[<sup>18</sup>F]FDG-PET Evaluation of Spinal Pathology in Patients in Oncology: Pearls and Pitfalls for the Neuroradiologist
2022, American Journal of NeuroradiologySurgical management of spinal metastases of thymic carcinoma: A case report and literature review
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