Clivus metastasis from gastric signet ring cell carcinoma after a 10-year disease-free interval--case report.

A 64-year-old male presented with an extremely unusual case of solitary clivus metastasis from gastric cancer manifesting as mild headache and diplopia 10 years after radical excision of the primary tumor. The patient underwent surgical resection using an endoscopic transsphenoidal approach. Histological examination revealed typical signet ring cell carcinoma (SRC) which was identical to that of the previous gastric cancer. Why the late recurrence occurred such a long time after the first surgery and how it spread to the clivus remain unclear. The characteristics of SRC and the process of "tumor dormancy" may have been involved in the mechanism underlying late metastasis.