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This chapter reviews the epidemiology of biliary tract cancer. Many etiologic leads for biliary tract cancer have come from clinical observations, autopsy series, and descriptive epidemiologic studies. While a significant fraction of these tumors are related to gallstones (cholelithiasis), information on other risk factors is limited, due to the rarity of the tumors, the often rapidly fatal course, and the small number of epidemiologic studies conducted to date. Because the three anatomic categories of biliary tract cancer have distinct epidemiologic patterns and molecular changes, including somatic mutations and loss of heterozygosity (LOH), it has been suggested that the causal factors vary by subsite.

This chapter covers core curriculum topics relating to disorders of the biliary tract including physiology and biochemistry of bile formation and the pathogenesis of gallstones; complications of gallstones disease including biliary colic, acute cholecystitis, biliary obstruction, and cholangitis, and options for operative and non-operative management. Material is also provided on conditions of the gallbladder including adenomyomatosis, gallbladder polyps, and porcelain gallbladder; primary sclerosing cholangitis and other causes of cholangitistumours of the bile duct, gall bladder, and ampulla; indications and complications of endoscopic and radiological treatment of biliary disease including endoscopic retrograde choalngiopancreatography, cholangioscopy, and Percutaneous transhepatic cholangiography. There is also discussion on the diagnosis and management of biliary complications after liver transplantation. Additional curriculum material regarding disorders of the biliary tract will also be covered in the mock examination chapter.

Biliary tract cancers encompass tumors of the gallbladder, extrahepatic bile ducts, and ampulla of Vater. In the United States, biliary tract cancer is the fifth most common malignant neoplasm of the digestive tract, accounting for about 3,700 deaths per year. The gallbladder is the primary subsite for 40% of biliary tract cancers, followed by the extrahepatic bile ducts (33%), ampulla of Vater (20%), and unspecified subsite (8%). Gallbladder cancer occurs twice as often in women than men, while other biliary tumors are more common in men. Risk of gallbladder cancer is elevated in Amerindians, including the Pima Indians in the United States and the Mapuches in Chile, and in certain Hispanic populations. While a significant fraction of these tumors are related to underlying gallstones (cholelithiasis), information on other risk factors is limited, due to the rarity of the tumors, the often rapidly fatal course, and small number of epidemiologic studies.

Starting a surgical job can feel like learning a completely new language. It may be the first time seeing patients in acute severe pain with a variety of lumps and bumps and a past history of previously unheard of complex operations. It can be easy to get hung up on whether the distended large bowel loop on the X- ray is a caecal or sigmoid volvulus or whether the strangulated hernia is femoral or inguinal. Ultimately, however, the most important point is that, as a junior doctor, it is being able to recognize that the patient is acutely unwell and may require an operation that will save lives. Ironically, a surgical rotation involves little time in the operating theatre— mostly, it will be spent dealing with problems during the peri-­operative period. This may start a week or two before the patient is even admitted, in the shape of a pre- assessment clinic, though these are increasingly nurse- led clinics with minimal input from junior doctors. Such clinics are, however, a good opportunity to see stable patients with interesting pathology and good clinical signs and to establish how well they look before the majority of their large bowel or their stomach is removed. The preoperative preparation of the patient goes beyond bloods and a cursory chat, and will require one to be on the lookout for previously undiagnosed cardiorespiratory or rheumatological conditions, among others, that might affect the patient getting to sleep or staying safely asleep under anaesthesia. Liaising with the anaesthetist about possible sources of difficulty well in advance of the planned procedure will ensure that operations do not get cancelled. The acute abdomen will take centre stage during general surgical takes. A thorough history and sound anatomical knowledge will help create a list of differential diagnoses. Accurate and careful palpation of the abdomen will reveal peritonism and the presence of any masses, and simple bedside observations and tests can greatly aid the diagnosis. Surgical specialties have a heavy reliance on imaging— erect chest X- ray, ultrasound, computed tomography (CT)/ magnetic resonance imaging (MRI) scan— each providing different information for the symp­toms displayed.

You have teased out the history, elicited the signs, and generated a list of differential diagnoses— now to confirm your suspicions, by selecting an appropriate radiological investigation. From the ubiquitous chest X-ray for diagnosing community- acquired pneumonia or congestive cardiac failure to an urgent computed tomography (CT) scan of the brain to confirm a suspected subarachnoid haemorrhage, radiological investiga­tions are an essential (if sometimes overused) resource for diagnosing disease. When working in the acute hospital setting, some knowledge and experience in interpreting X- rays and some types of CT imaging are important in order to ensure your patient is managed correctly and quickly. Going back to basic principles and using your hard- learnt anatomy will set you in good stead when looking at both X- rays and cross- sectional imaging. This chapter has been written to expose you to clinical situations where imaging is required to make a diagnosis or to make a decision on patient management. As well as this, I hope the questions in this chapter will help you think about what the correct modality of imaging to request would be to investigate pathology in the various body systems. For instance, an ultrasound of the liver may be more useful to assess liver cirrhosis than a CT scan (as well as preventing exposures to high- dose radiation). And again, in practice, if there is any doubt about the result of a radiological investigation, or indeed which type of investigation to request, your local radiologist would be more than happy to help.

Basic sciences: Applied anatomy

A 65-year-old presents to his GP with weakness along the right side of his mouth and lower lip. He states that he has difficulty in closing his mouth and is unable to move his lower lip. On examination, there is...

Basic sciences: Applied anatomy

Which of the following nerves does not arise from the medial cord of the brachial plexus?

Medial cutaneous nerve of the forearm

Medial pectoral nerve

Musculocutaneous nerve

Ulnar nerve

Median cutaneous nerve of the arm...

Questions

A 56-year-old woman with terminal breast cancer and spinal metastases comes to the emergency department. She complains of lower back pain and neuopathic pain going down her lefit leg. Current analgesia includes paracetamol and oramorph. On examination her BP is 145/82, pulse is...

Yes, the likelihood of certain diseases would change considerably. In older patients, certain pathologies are relatively more common, such as pneumonia, cancer (e.g. hepatocellular carcinoma), or vascular disease (aortic dissection, abdominal aortic aneurysm, inferior myocardial infarction). Of course, the differential would still include those diseases seen in a 38-year-old Mrs Cole. Characterize the pain. One useful way is to follow the mnemonic SOCRATES: Site of pain, and has it moved since it began? Onset of pain—was it sudden or gradual, and did something trigger it? Character of pain—stabbing, dull, deep, superficial, gripping, tearing, burning? Radiation of pain—does the patient have pain elsewhere? Attenuating factors—does anything make the pain better (position? medications?) Timing of pain—how long has it gone on for, has it been constant or coming and going? Exacerbating factors—does anything make the pain worse (moving? breathing?) Severity—on a scale of 0–10, where 10 is the worst pain ever (e.g. childbirth). Once you have characterized the pain, you should ask: • Has the patient had any symptoms other than pain? (e.g. fever, weight loss). The reason is that certain other symptoms will help you refine your diagnosis. Thus, fever suggests an infective process and makes a myocardial infarction less likely. Significant weight loss over the preceding months may be due to a cancer, which is a catabolic process (breakdown of tissues for energy). • When did they last open their bowels or pass any flatus (wind)? A patient who hasn’t opened their bowels may be constipated, but a patient who isn’t even managing to pass wind (‘absolute constipation’) may be obstructed—a surgical emergency. • Have they noticed any change in their stool recently? (e.g. colour, floating, smelly). If the common bile duct is obstructed, bilirubin and fat-dissolving bile salts won’t reach the bowel and thus stools will be pale, floating, and smelly (steatorrhoea). If blood is entering the bowel lumen via a bleeding ulcer, the iron (haemoglobin) in the blood will be oxidized, making stools appear very dark, black, tarry, and smelly (melaena).

Basic sciences: Applied anatomy

Which among the following statements regarding the functions of the extraocular muscles is incorrect?

The inferior oblique muscle abducts the eye and moves it upwards

The superior rectus muscle abducts the eyes and moves it laterally

The...

Basic sciences: Applied anatomy

Which among the following statements concerning the lymphatic drainage of the colon is incorrect?

Lymph from the intermediate mesocolic lymph nodes drain to the principal nodes

Lymph from the caecum drains into the principal nodes at the origin...