Vertebral Metastasis from Squamous Cell Carcinoma of the Anal Canal

Distant metastasis of squamous cell carcinoma from the anal canal is an uncommon event. However, hematogenous spread to the vertebrae may occur in the course of this disease. The route of metastasis from the anal canal seems to be Batson's vertebral venous system. A 52-year-old female patient presented with lower back and right leg pain of one-week history. She has undergone radiotherapy and chemotherapy for squamous cell carcinoma of the anal canal and then was followed by surgical resection. Three months later, magnetic resonance images of the lumbar spine disclosed a well-enhanced mass of L5 vertebral body compressing the thecal sac. Surgical decompression and biopsy were performed. Histopathological study confirmed carcinoma of the squamous cell origin. We report a ra re case of vertebral metastasis from squamous cell carcinoma of the anal canal with a pertinent review of literature.