Saturday, April 10, 2010

Dysphagia case 4

A 35-year-old woman consults a physician because she has been having trouble swallowing. She also often experiences chronic heartburn. The physician performs a screening physical examination, and notices that the skin of her hands appears tight and shiny. On specific
questioning, she reports having often experienced color changes in her hands from white to blue to red.

Which of the following is the most likely cause of the patient's difficulties with swallowing?
/ A. Achalasia
/ B. Adenocarcinoma
/ C. Chagas disease
/ D. Scleroderma
/ E. Squamous carcinoma

The color changes described on the patient's hand are most likely due to which of the following?
/ A. Arteriolar spasm
/ B. Blood clots at sites of vascular injury
/ C. Large artery spasm
/ D. Platelet clots
/ E. Stasis blood clots

Q 3
Additional findings on physical examination include noting that the skin changes are limited to areas distal to the elbow and knee, the presence of calcified nodules on the extensor surfaces of the forearms, and the presence of telangiectasias on the forearms. This suggests
that this patient has which of the following?
/ A. Bauer syndrome
/ B. Charcot syndrome
/ C. CREST syndrome
/ D. Crigler-Najjar syndrome
/ E. Dandy-Walker syndrome

Q 4
If this woman's involved skin were biopsied, which of the following would most likely be seen?
/ A. Cleft separating the dermis and subcutaneous tissues
/ B. Epithelial cell hyperplasia
/ C. Marked dermal fibrosis
/ D. Narrowing of the basal lamina of small capillaries
/ E. Thickening of rete pegs

Q 5
More than 90% of the patients with the limited cutaneous form of this disorder make which of the following autoantibodies?
/ A. Anti-centromere
/ B. Anti-DNA topoisomerase l
/ C. Anti-double-stranded DNA
/ D. Anti-Golgi
/ E. Anti-ScI-70


Dysphagia case 4 answers

The correct answer is D. The tip-off is the reference to the patient's skin changes that are typical for scleroderma, also known as systemic sclerosis. Scleroderma is a disease that may be either predominately limited to the skin or involve many body systems, including the musculoskeletal system, gastrointestinal tract (with esophageal involvement most often symptomatic), cardiorespiratory system, and renal system. Esophageal dysfunction is a common complication of scleroderma. In most patients, the skin changes are obvious, even if the patient has not been previously diagnosed. Rarely, the skin changes may be noticed at an earlier stage, in which the skin of the hands appears puffy and edematous, but not scarred.
Achalasia (choice A) and Chagas disease (choice C) are also important causes of dysphagia, but in achalasia, the physical examination is usually normal, and in Chagas disease, you should be able to elicit a history of possible exposure in Central or South America.
Reflux esophagitis with risk of progression to Barrett esophagus and adenocarcinoma (choice B) can occur in scleroderma, but it is unlikely, at this early stage in the patient's disease, that she already has adenocarcinoma.
The risk of squamous cell carcinoma (choice E) is not increased in this patient.

The correct answer is A. The color changes described are typical for Raynaud's phenomenon, which occurs because of changes in perfusion due to arteriolar spasm. Raynaud's phenomenon is common in scleroderma, largely because the subintimal hyperplasia of small vessels characteristic of scleroderma can reduce the luminal diameter by more than 75%. Some authors argue that the vascular changes seen in scleroderma are actually the insult that triggers the subsequent development of fibrosis.
Blood clots at sites of vascular injury (choice B) are typical in clots that form in arteries on surfaces such as a fractured atherosclerotic clot.
Larger artery spasm (choice C) of vessels damaged by atherosclerosis is thought to contribute to some myocardial infarctions, but is not thought to be an important pathologic mechanism in scleroderma.
Platelet clots (choice D) can be seen in some diseases in which platelet function is abnormal, such as essential thrombocytopenia.
Stasis blood clots (choice E) commonly are found in venous thromboses.

The correct answer is C. These findings, together with esophageal dysfunction and Raynaud's phenomenon (both of which this patient has), are called the CREST syndrome, also known as limited cutaneous scleroderma. This form of scleroderma has a better long-term prognosis than when the skin changes also involve the trunk (diffuse scleroderma) and more internal organs are additionally involved.
Bauer syndrome (choice A) is aortitis and aortic endocarditis as a complication of rheumatoid arthritis.
Charcot syndrome (choice B) is intermittent claudication.
Crigler-Najjar syndrome (choice D) is a severe familial liver disease.
Dandy-Walker syndrome (choice E) is a malformation of the central nervous syndrome.

The correct answer is C. In scleroderma, early changes (at the point at which the hands appear swollen, rather than with tight, thick skin) show edema with perivascular infiltrates of CD4+ T cells. At this stage, the collagen fibers are swollen and beginning to degenerate. The smaller vessels may show basal lamina thickening (not narrowing as in choice D) and endothelial (not epithelial cell hyperplasia) cell damage and proliferation. With time, the characteristic marked dermal fibrosis develops, which tends to both narrow (not thicken as in choice E) the rete pegs and attach the dermis tightly (compare with cleft formation as in choice A) to subcutaneous tissues.

The correct answer is A. All forms of scleroderma are thought to have a strong autoimmune component, and glucocorticoids and azathioprine are used to suppress the inflammatory complications of scleroderma. (Other drugs that can be used in therapy include penicillamine, which inhibits collagen cross-linking, NSAIDS for pain, and ACE inhibitors to protect the kidney if hypertension or renal damage occurs.) The anti-centromere antibody is quite specific for CREST syndrome (96% of cases), and is only seen in a minority of patients with diffuse scleroderma (mainly those with Raynaud's phenomenon) and rarely in systemic lupus erythematosus and mixed connective tissue disease.
Anti-DNA topoisomerase I (choice B), also called anti-Scl-70 (choice E) occurs commonly (64-75%) in diffuse scleroderma, but only rarely in CREST syndrome.
Anti-double-stranded DNA (choice C) is fairly specific for systemic lupus erythematosus, although it only occurs in 50-60% of lupus cases.
Anti-Golgi antibodies (choice D) are seen most often in systemic lupus erythematosus and Sjögren syndrome.

Dysphagia case 3

A 30-year-old man consults a physician because he has been having increasing difficulty swallowing both solids and liquids. Physical examination of the patient is noncontributory. Barium swallow studies show a mostly dilated esophagus with slow passage of barium into the
stomach. The very distal part of the esophagus appears narrowed into a "bird's beak." Esophageal manometry shows incomplete relaxation of the lower esophageal sphincter in response to swallowing, high resting lower esophageal pressure, and absent esophageal peristalsis.

Q 1

The manometry and barium swallow studies most strongly support which of the following diagnoses?
/ A. Achalasia
/ B. Adenocarcinoma
/ C. Barrett esophagus
/ D. Squamous cell carcinoma
/ E. Systemic sclerosis

Q 2
This patient's condition is most likely due to which of the following?
/ A. Acid reflux
/ B. Cancerous destruction
/ C. Candida infection
/ D. Fibrosis of the esophageal wall
/ E. Lack of ganglion cells

Q 3
Which of the following regulators would most likely inhibit the lower esophageal sphincter in normal individuals?
/ A. Acetylcholine and substance P
/ B. Substance P and nitric oxide
/ C. Substance P only
/ D. Vasoactive intestinal polypeptide and acetylcholine
/ E. Vasoactive intestinal polypeptide and nitric oxide

Which of the following medications is used to directly relax the lower esophageal sphincter?
/ A. Diphenoxylate
/ B. Famotidine
/ C. Granisetron
/ D. Isosorbide dinitrate
/ E. Metoclopramide

Q 5
Worldwide, which of the following parasitic diseases is most likely to produce a disorder that clinically resembles this patient's condition?
/ A. Ascariasis
/ B. African sleeping sickness
/ C. Chagas disease
/ D. Cysticercosis
/ E. Malaria


Dysphagia case 3 answers

The correct answer is A. The most likely diagnosis is achalasia. This condition is a neurogenic esophageal disorder that can occur at any age, but frequently is diagnosed when individuals are between the ages of 20 and 40. Characteristically, the swallowing difficulties involve both solid food and liquids. The manometry findings illustrated are typical; the barium swallow findings may be as illustrated or may instead show diffuse esophageal dilation without the "bird's beak" near the lower esophageal sphincter.
Larger cancers of the esophagus (choices B and D) would be more likely to cause either a mass or an ulceration, which would be visible on barium swallow.
Very small cancers and Barrett's esophagus (choice C) would require esophagogastroduodenoscopy with biopsy for diagnosis, and would be unlikely to cause dysphagia.
Systemic sclerosis (choice E) can involve the esophagus as well, however, physical examination would usually show obvious skin involvement.

The correct answer is E. Individuals who have achalasia have been found to have a deficiency of inhibitory ganglion cells within the esophageal wall. This lack causes an imbalance in excitatory and inhibitory neurotransmission, with the result that the lower esophageal sphincter tends to have a higher-than-normal muscle tone and relaxes only with difficulty.
Acid reflux (choice A) can cause esophageal irritation, ulceration, and also predisposes for Barrett's metaplasia with subsequent risk of adenocarcinoma of the esophagus.
Cancerous destruction (choice B) would produce a mass, or area of stricture or ulceration.
Candida infection (choice C) of the esophagus resembles thrush of the mouth, and causes a usually superficial infection.
Fibrosis of the esophageal wall (choice D) can be the consequence of ulceration (due to reflux or ingestion of harsh chemicals such as lye) or systemic sclerosis.

The correct answer is E. Physiologically important inhibitors of the lower esophageal sphincter include nitric oxide and vasoactive intestinal polypeptide. Physiologically important substances that stimulate the lower esophageal sphincter include acetylcholine and substance P.

The correct answer is D. Commonly used medications to relax the lower esophageal sphincter in patients with achalasia include nitrates such as isosorbide dinitrate (remember that nitric oxide physiologically inhibits the lower esophageal sphincter) and calcium channel blockers such as nifedipine (which inhibit calcium flow into the smooth muscle of the lower esophageal sphincter, thereby inhibiting contraction.) For patients in whom medical therapy fails, other options include paralysis of the lower esophageal sphincter with intrasphincteric injection of botulinum toxin, pneumatic dilatation, and a Heller myotomy (which interrupts the muscles of the lower esophageal sphincter).
Diphenoxylate (choice A) is a opiate antidiarrheal, and would not be useful for achalasia.
Famotidine (choice B) is an H2 antagonist that would be useful in reducing stomach acidity, but would not directly affect lower esophageal pressure. Other drugs in this class include cimetidine, ranitidine, and nizatidine.
Granisetron (choice C) is a 5HT3 antagonist and is used to prevent nausea and vomiting in patients who receive chemotherapy, and after general anesthesia. Other members of this drug class include ondansetron and dolasetron.
Metoclopramide (choice E) stimulates gastric motility in patients with gastroparesis and is also a antiemetic agent.

The correct answer is C. Chagas disease, which is found in South and Central America and is due to infection with Trypanosoma cruzi, can involve the heart, colon, and esophagus. The esophageal involvement clinically closely resembles achalasia.
The adult worms of ascariasis (choice A), or roundworm infection, live principally in the intestine, and can obstruct the intestine or a bile duct; the larvae can migrate to the liver, heart, and lungs.
African sleeping sickness (choice B), caused by Trypanosoma brucei and Trypanosoma gambiense, causes lymphadenopathy, rash, and CNS involvement.
Cysticercosis (choice D), due to the larval form of the pork tapeworm Taenia solium, can involve subcutaneous tissue, muscle, viscera (but not specifically the esophagus), and, most seriously, the CNS.
Malaria (choice E), due to various Plasmodium species, involves the blood, liver, kidney, spleen, and brain, but does not have a specific predilection for the esophagus.

Dysphagia case 2

A 65-year-old man presents to his physician because he has been having increasing difficulty swallowing over the past 2 months. He is still able to swallow liquids, but swallowing solid food now causes severe pain and a sense of fullness behind his sternum. He has lost 18 pounds
since his swallowing difficulties began. The patient is referred to a gastroenterologist, who demonstrates a mass lesion of the distal esophagus, which on biopsy is shown to contain cancer.


Which of the following is most important in separating the esophagus from the larynx, and must consequently be carefully passed behind
during endoscopy?
/ A. Arytenoids
/ B. Cricoid cartilage
/ C. Epiglottis
/ D. Pharynx
/ E. Vocal cords

Which of the following nerves provides the efferent impulses necessary for the esophageal actions that occur during swallowing?
/ A. Glossopharyngeal
/ B. Hypoglossal
/ C. Spinal accessory
/ D. Trigeminal
/ E. Vagus

Which of the following approximately represents the proportion of different esophageal cancer types now being observed in the United States?
/ A. 1/10 adenocarcinoma and 9/10 squamous cell carcinoma
/ B. 1/3 adenocarcinoma and 2/3 squamous cell carcinoma
/ C. 1/2 adenocarcinoma and 1/2 squamous cell carcinoma
/ D. 2/3 adenocarcinoma and 1/3 squamous cell carcinoma
/ E. 9/10 adenocarcinoma and 1/10 squamous cell carcinoma

Q 4
Precancerous metaplasia of the esophageal epithelium gives rise to a mucosa resembling which of the following?
/ A. Mesothelium
/ B. Respiratory epithelium
/ C. Small intestine
/ D. Squamous epithelium
/ E. Stomach

Frequent use of which of the following has recently been found to probably have a protective effect against development of esophageal
/ A. Acetaminophen
/ B. Alcohol
/ C. Aspirin
/ D. Cigarettes
/ E. Codeine

Q 6
Currently, esophageal cancer has which of the following long-term survival rates?
/ A. Less than 5%
/ B. 30%
/ C. 50%
/ D. 70%
/ E. More than 95%


Dysphagia case 2 answers
The correct answer is C. Endoscopists are very careful when guiding the endoscope past the epiglottis, which is a pear-shaped portion of elastic cartilage that can be moved during swallowing to close the larynx, preventing swallowed material from eventually entering the lungs.
The arytenoids (choice A) are the site of the attachment of the vocal cords (choice E) within the larynx.
The cricoid cartilage (choice B) is in the more distal portion of the larynx.
The pharynx (choice D) is shared by the respiratory and gastrointestinal tracts.

The correct answer is E. The vagus nerve supplies the efferent input into the esophagus that is necessary for swallowing.
The glossopharyngeal nerve (choice A) provides taste and sensation on the palate, but the only muscle it supplies is the stylopharyngeus.
The hypoglossal nerve (choice B) moves the tongue during the initiation of swallowing, but does not innervate the esophagus.
The spinal accessory nerve (choice C) plays no role in swallowing. This nerve mediates head and shoulder movement and innervates laryngeal muscles.
The trigeminal nerve (choice D) provides general sensation to the mouth and motor innervation to the muscles of mastication.

The correct answer is C. More recent statistics indicate that the incidence of adenocarcinoma and squamous cell carcinoma of the esophagus are now roughly equal. Formerly, approximately 2/3 of the esophageal cancers were squamous in origin (choice B). Adenocarcinoma of the esophagus is often found in the distal esophagus.

The correct answer is C. This is an indirect question about Barrett's esophagus, which is an important precursor of adenocarcinoma of the esophagus. While Barrett's esophagus was initially defined to be either gastric-type or intestinal-type metaplasia of the esophagus, more recent studies have shown that the actual problem lesion is more likely to be intestinal metaplasia (diagnosed when isolated goblet cells are seen in the epithelium) rather than gastric metaplasia (choice E).
Metaplasia to mesothelium (choice A) or ciliated respiratory epithelium (choice B) does not usually occur in the esophagus.
The normal epithelium of most of the esophagus is squamous (choice D).

The correct answer is C. An interesting new research observation that may be exploited in the future is that the incidence of esophageal cancer appears to be much lower in people who use aspirin frequently.
Cigarettes (choice D) and alcohol use (choice B) have been implicated as risk factors for esophageal cancer.
Acetaminophen (choice A) and codeine (choice E) have no known effects on the incidence of esophageal cancer.

The correct answer is A. Esophageal cancer is one of the very bad cancers, presently with poor long-term survival. The underlying problem is that the esophagus is only about 3 mm thick, and both metastatic disease and direct spread (often unresectable) to mediastinal structures is common. Active research is presently being undertaken to modify this prognosis by using chemotherapy and radiation therapy prior to surgery, but these modalities have not yet come into widespread use.

Dysphagia Case 1

A 25-year-old woman consults a physician because she has developed severe dysphagia and constipation that has led to a recent weight loss of 15 pounds. She is referred to a gastroenterologist, to whom she reports that she has a great deal of trouble swallowing solid foods, but not liquids, and has also been having nearly constant gastroesophageal reflux symptoms. She has awakened during the night several times coughing and feeling as if she had aspirated acid stomach contents. Esophagogastroduodenoscopy and colonoscopy are performed, and demonstrate massive dilatation of the esophagus and colon.

Q 1
Which of the following parasitic diseases would most likely produce megaesophagus and megacolon?
/ A. Chagas disease
/ B. Cysticercosis
/ C. Hydatid disease
/ D. Malaria
/ E. Threadworm infection

The infecting species is which of the following?
/ A. Fluke
/ B. Nematode
/ C. Plasmodia
/ D. Tapeworm
/ E. Trypanosome

Q 3
On further questioning, the woman reports having lived for a year in Bolivia as a teenager. At one point, she had had an automobile accident and had been transfused with blood at a local hospital there. The person whose blood she received had probably acquired the infection via a
bite by which of the following?
/ A. Flea
/ B. Mosquito
/ C. Reduviid bug
/ D. Tick
/ E. Tsetse fly

While this woman's gastrointestinal tract disease brought her to medical attention, involvement of which of the following is the principal source of morbidity and mortality in this condition?
/ A. Heart
/ B. Kidneys
/ C. Liver
/ D. Lungs
/ E. Pancreas

Q 5
While no drug therapy is useful in the therapy of chronic cases, treatment can be used in newly diagnosed acute cases. Which of the following medications would be most useful in treating the acute infection?
/ A. Chloroquine
/ B. Doxycycline
/ C. Nifurtimox
/ D. Primaquine
/ E. Pyrimethamine-sulfadoxine


Dysphagia case 1 answers
The correct answer is A. Megaesophagus and megacolon are unusual pathologic changes, and should bring Chagas disease to mind, which is also known as American trypanosomiasis. Megacolon, but not megaesophagus, can also be due to Hirschsprung disease, but this is usually diagnosed in infants and young children and is due to abnormal neural development in the gut.
Cysticercosis (choice B) can cause cyst formation in the brain and other organs.
Hydatid disease (choice C) can cause cysts in the liver and other organs.
Malaria (choice D) can be complicated by fever, chills, anemia, splenomegaly, and in severe cases, renal failure, coma, thrombocytopenia, and respiratory distress syndrome.
Threadworm infection (choice E) can cause skin rashes, eosinophilia, abdominal pain, and, in severe cases, massive GI bleeding, severe malnutrition, and severe pulmonary symptoms

The correct answer is E. Chagas disease is caused by infection with Trypanosoma cruzi, which is an intracellular protozoan parasite that takes a leishmanial form within muscle cells.
Examples of fluke (choice A) or trematode diseases include schistosomiasis (blood flukes), paragoniasis (lung fluke), and various liver flukes (e.g., clonorchiasis, fascioliasis, fasciolopsiasis).
Examples of nematode (choice B), or round worm diseases, include the various intestinal nematodes (e.g., ascariasis, trichuriasis, ancylostomiasis, strongyloidiasis), tissue nematodes (e.g., toxocariasis, trichinosis, dracunculosis), and the filarial nematodes (e.g., elephantiasis, onchocerciasis).
Plasmodia (choice C) cause malaria.
Tapeworm infections (choice D) include intestinal infections (diphyllobothriasis, Taenia infections), cysticercosis (due to Taenia solium), and Echinococcus infections.

The correct answer is C. Reduviid bugs are insects that live in poorly constructed adobe housing and feed on human or animal blood. Trypanosomes they ingest during their feedings multiply in the insect gut and are deposited in fecal material near the wound when the insect bites another individual. Contamination through the wound leads to invasion into, and reproduction within, host cells. Release of the trypanosomes back into the blood stream makes them available for transmission either via another bug bite or via blood transfusion. Transmission of Chagas disease via blood transfusion has also become an important mode of transmission in South America. Santa Cruz, Bolivia is thought to have a prevalence of infected blood in blood banks of 53%, which is much higher than the rate of hepatitis or HIV infection. In other parts of South America, the infection rate is much lower, due primarily to a massive attempt by the World Health Organization to eliminate both the reduviid bug (through better housing and insecticide use) and screen for Chagas disease in blood products in endemic regions. These attempts have been most successful in eradicating or nearly eradicating the infection in Chile, Uruguay, and Brazil. Transmission of Chagas disease via blood transfusions has not been a significant problem in the United States, primarily because one of the questions asked before a blood donation is taken is whether or not a person has traveled outside the United States during the previous year. While Chagas disease can persist for decades, the period in which significant numbers of parasites are in the blood is usually only during the comparatively short (and often asymptomatic) acute phase of the illness.
Flea-borne illnesses (choice A) to remember include bubonic plague and typhus.
Associate mosquito bites (choice B) with malaria.
Associate tick bites (choice D) with Lyme disease, babesiosis, and Rocky Mountain spotted fever. Associate Tsetse fly bites (choice E) with African trypanosomiasis (sleeping sickness).

The correct answer is A. Chagas disease is conventionally divided into three stages. The short acute period may be asymptomatic or may be characterized by fever, swelling of lymph glands, hepatosplenomegaly, and local inflammation at the site of the bite. This is followed by an asymptomatic period, which may last years to the rest of the patient's life. In one-third of patients, clinically evident disease becomes apparent 10-20 years after infection. 27% of infected patients develop cardiac symptoms (which may cause flaccid cardiomyopathy, cardiac aneurysm formation, or sudden death); 6% develop digestive system damage with megaviscera (thought to be related to neural involvement rather than muscle involvement); and 3% develop neural involvement. You should also be aware that coexisting AIDS infection may predispose for an unusually rapid and severe course of Chagas disease.
The kidneys (choice B), liver (choice C), lungs (choice D), and pancreas (choice E) are not particular targets in this disease.

The correct answer is C. The diagnosis in suspected acute cases can be established with review of thin or thick blood smears. (The diagnosis in latent and chronic cases usually requires special blood culture techniques or PCR-amplified detection of parasite DNA in blood.) The only effective drugs are nifurtimox and benznidazole, which are given in courses up to 4 months because the organisms are difficult to eradicate. The other choices listed are drugs used in malaria prophylaxis or treatment.