Cholangiocarcinoma, also known as bile duct cancer, is cancerous growth in the bile ducts, which serve to carry bile from the liver to the small intestine. While it is rare, it is usually quite lethal as it is not usually detected until an advanced stage of growth at which point it has usually metastasized. Risk factors for developing cholangiocarcinoma include any condition where the bile ducts are inflamed chronically, like primary sclerosing cholangitis (PSC), infection with parasitic worms/liver flukes, bile duct cysts or chronic biliary irritation.
Clay-Colored Stools
Normally the liver releases bile salts which find their way into the stool to give them their normal brown color. When bile flow out of the liver is obstructed (by a tumor in the bile ducts for example) these salts do not enter the stool and as a result the stools can be clay colored, or "acholic."
Fever
There are many reasons why cancer causes fever, many of which are poorly understood. Cancers can release inflammatory mediators such as pyrogens or toxins that result in fever in addition to weakening the hosts immune system resulting in infection, which can cause its own fever as well. The fever itself can also be cyclical, or it can go away for weeks and recur with no warning.
Itching
This is known as "pruritus" and results from the bile salts that normally enter the small intestine being obstructed and being deposited in the skin. The itchiness is usually all over the body.
Pain
The causes for this are also poorly understood but can occur for a variety of reasons such as local impingement on surrounding structures. The pain has been noted to radiate to the back in many cases and is usually located abdominally.
Weight Loss
Many cancer syndromes result in weight loss which also have many, sometimes not well understood, causes. The cancer can release inflammatory cytokines which have been hypothesized to play a role in the weight loss; and the obstruction of bile, which aids in digestion can result in malabsorption syndromes as well.
Jaundice
Bile contains a substance called bilirubin, which is a normal breakdown product of expired red blood cells. Normally, bilirubin enters the bile and leaves the liver this way; however, when obstruction occurs in the bile ducts (such as from a tumor), the bilirubin does not leave the bile and can re-enter the bloodstream and eventually be deposited in the skin, giving it the characteristic yellow look. It can also be deposited in the sclera of the eye, and usually that is how the diagnosis of jaundice is made in dark-skinned individuals where it is difficult to appreciate yellowing in the skin.
Considerations
The above symptoms are part of a clinical constellation of both signs and symptoms, both subjective and objective. Care must be taken on the part of the patient to not try and misinterpret individual symptoms into presumptive diagnoses and whenever any questions exist, never hesitate to consult a healthcare professional.
References
- Emedicine: Cholangiocarcinoma Overview
- Medline: Cholangiocarcinoma
- Sleisenger & Fordtran's Gastrointestinal and Liver Disease. Feldman 2006
