Metastatic Spinal Tumor from Benign Pleomorphic Adenoma: Case Report and Literature Review

Pleomorphic adenomas tend to arise in the salivary glands. They are rare and histologically benign but can result in distant metastasis, and their characteristics need further investigation. We report a case of locally recurring benign primary palatal pleomorphic adenoma that resulted in spinal metastases and review the relevant literature.

A 58-year-old woman had undergone surgery for a palatal pleomorphic adenoma 22 years earlier and 6 subsequent operations for local recurrences. During follow-up, metastases to multiple organs, including the spine, were diagnosed and 4 CyberKnife treatments were performed. She suffered right flank pain and slight paralysis of the right leg; radiological findings showed a growing metastatic spinal tumor. She underwent removal of a thoracic vertebral tumor and posterolateral fusion. Postoperatively, her symptoms improved. Histopathological analysis indicated a pleomorphic adenoma and no evidence of malignancy. Although there was no local recurrence, 23 months after surgery, a fifth CyberKnife procedure was performed for a growing salivary gland tumor and she is currently being followed up.

We described a rare case of benign pleomorphic adenoma that metastasized to the spine. Long-term follow-up for recurrence and metastasis is required for patients with benign pleomorphic adenoma.