Severe autonomic dysfunction as a presenting feature of Wilson's disease.

While the small intestine accounts for nearly 75% of the total length of the GI tract and more than 90% of the mucosal surface area, less than 25% of all alimentary tract neoplasms and less than 2% of all malignant tumours originate from the small intestine. This could be due to the relatively rapid transit time, liquid content of stools, low bacterial population, and a high concentration of IgA within the lumen. Metastatic tumours of the small bowel outnumber the primary tumours and usually occur as part of generalised peritoneal carcinomatosis. Rarely are these metastatic tumours solitary. The different mechanisms postulated for isolated small bowel metastasis include retrograde lymphatic spread following blockade of paraaortic or mediastinal lymph nodes, lymphatic embolisation, haematogenous spread or peritoneal seeding, including direct implantation. The ileum is the commonest site of metastatic lesions in the small intestine, probably because of the large number of Peyer’s patches, which make it the best trapping zone for hematogenic metastasis.