Treatment for Spinal Metastasis of Gastrointestinal Stromal Tumors: Two Case Reports

Gastrointestinal stromal tumors (GISTs) are rare, but represent the most common mesenchymal neoplasms of the gastrointestinal tract. The lung and liver are the most frequent sites of distant diseases, but the spinal involvement of metastatic GISTs is very rare. We describe two cases of spinal metastases in patients with advanced GISTs. A 71-year-old female was diagnosed with GIST in 2003 after wedge resection of the stomach. As she had liver metastases, imatinib mesylate was given. Thirteen years later, it was found that she had a sacral metastatic lesion due to buttock pain. Sacral laminectomy and tumor removal surgery were done. Results of the pathologic biopsy showed that she had sacral metastasis from GIST. A 69-year-old male was diagnosed with GIST in 2009 after surgery. Pathologic reviews showed that he had omentum and lymph node metastasis. After surgery, imatinib mesylate was given to the patient as an adjuvant treatment. In 2017, it was found that he had multiple spinal metastatic lesions. A percutaneous biopsy was performed, and pathologic results showed that he had metastasis from GIST. He underwent palliative radiosurgery. Although spine metastases from GISTs are uncommon, metastasis must be considered to the patients who previously had GISTs. Key words: Gastrointestinal stromal tumors; Neoplasm metastasis; Radiosurgery; Spinal neoplasms