Comprehensive review of small bowel metastasis from head and neck squamous cell carcinoma.

Secondary tumours of small intestine account for 10% of all small bowel cancers. The most common sites of primary tumour metastasizing to small bowel are uterus, cervix, colon, lung, breast and melanoma. The majority of these metastatic tumours come from adenocarcinoma primaries; squamous cell carcinoma constitutes a very small proportion of all metastatic small intestinal lesions. Metastasis to small bowel by head and neck squamous cell carcinoma is extremely rare and carries an unfavourable prognosis. Owing to the limited number of published studies, its characteristic features, clinical presentation and outcomes are poorly described. This work aims at specifying these characteristics by reviewing, compiling, analysing and reporting all published cases in the published literature on small bowel metastasis secondary to head and neck squamous cell carcinoma. To the best of our knowledge, this is the first comprehensive review article on the small intestinal metastasis from head and neck squamous cell carcinoma.