Arteriovenous carcinoembryonic antigen gradient: determination by selective angiography for localization of metastatic colorectal cancer.

Two colorectal carcinoma patients with elevated serum carcinoembryonic antigen (CEA) levels are discussed. In the first patient, metastatic disease in the left adrenal gland was diagnosed by computerized tomography scanning. A CEA concentration gradient between the left adrenal artery and the left adrenal vein was detected by selective sampling of the appropriate vessels. After adrenalectomy, the serum CEA level returned to normal. In the second patient, a CEA gradient between the hepatic artery and the left hepatic vein helped localize metastatic disease in the left lobe of the liver, before it became evident by any other means. We conclude that subselective angiography and sampling of serum for CEA levels could serve as an auxiliary method of detecting obscure metastatic colorectal carcinoma in patients with elevated levels of the antigen.