MCQ: GASTROINTESTINAL PATHOLOGY — 60 MCQs (Redistributed...

Question 1

A 3-year-old presents with painful oral vesicles and ulcerations, high fever, and refusal to eat. His mother reports this began abruptly. Biopsy of the lesion edge reveals multinucleated polykaryons with eosinophilic intranuclear inclusions. What is the diagnosis?

Accepted Answer

Acute herpetic gingivostomatitis from primary HSV-1 infection — Primary HSV-1 infection in 2–4 year olds presents as acute herpetic gingivostomatitis. The morphologic hallmarks are multinucleated polykaryons and eosinophilic intranuclear inclusions. ---

Question 2

A 52-year-old male smoker has a white patch on his buccal mucosa that cannot be scraped off. Biopsy shows moderate epithelial dysplasia. What is the most accurate statement about this lesion?

Accepted Answer

It must be considered precancerous until proved otherwise by histology — All leukoplakias must be considered precancerous regardless of clinical appearance. 5–25% are premalignant. 50% transformation rate applies to erythroplakia, not leukoplakia. ---

Question 3

A 45-year-old woman develops a red, velvety slightly depressed lesion on the floor of her mouth. She is a non-smoker with no alcohol use. Which statement is most accurate regarding this lesion?

Accepted Answer

It has greater malignant transformation risk than leukoplakia with >50% of cases transforming — Erythroplakia carries a much greater malignant transformation risk than leukoplakia, with 50% of cases undergoing malignant transformation regardless of tobacco history. ---

Question 4

A 35-year-old male has a rapidly growing pedunculated red-purple gingival mass. His wife is 7 months pregnant and has a similar lesion. Biopsy shows immature vessel proliferation resembling granulation tissue. What is this lesion and its behaviour?

Accepted Answer

Pyogenic granuloma — may regress, fibrose, or become peripheral ossifying fibroma — Pyogenic granulomas are richly vascular pedunculated gingival masses common in pregnant women and young adults. They can regress, mature into fibrous masses, or develop into peripheral ossifying fibroma. ---

Question 5

An HPV-related oral SCC at the base of tongue is identified in a 40-year-old non-smoking male. Compared to tobacco-related oral SCC, this tumour is expected to show

Accepted Answer

Fewer mutations, overexpression of p16, and better prognosis — HPV-related oral SCC (predominantly HPV-16) has fewer overall mutations, overexpresses p16 (cyclin-dependent kinase inhibitor), and carries a better prognosis than tobacco/alcohol-related SCC. ---

Question 6

A 65-year-old woman complains of extreme dry mouth, difficulty swallowing, and recurrent dental caries. She is on multiple medications for hypertension and depression. What is the most common cause of her xerostomia?

Accepted Answer

Medications — anticholinergic and antidepressant agents — Medications are the most frequent cause of xerostomia, including anticholinergic, antidepressant, antihypertensive, and diuretic agents. Sjögren syndrome is the second most important cause. ---

Question 7

A 25-year-old male presents with a fluctuant swelling of his lower lip that enlarges before meals and shrinks afterwards. What is the most likely diagnosis and its pathogenesis?

Accepted Answer

Mucocele — blockage or rupture of a minor salivary gland duct with saliva leakage — Mucocele is the most common inflammatory salivary gland lesion, resulting from duct blockage or rupture with saliva leakage into surrounding stroma. The fluctuant lower lip swelling that changes size around meals is characteristic. ---

Question 8

A neonate presents with regurgitation during the first feeding, aspiration, and abdominal distention from gas below the diaphragm. What is the most likely oesophageal abnormality and its most common variant?

Accepted Answer

Oesophageal atresia with distal tracheoesophageal fistula — most common variant — The most common variant is oesophageal atresia with a distal tracheoesophageal fistula. Gas below the diaphragm indicates a distal fistula allowing air into the GI tract. ---

Question 9

A 38-year-old male presents with dysphagia to both solids and liquids, regurgitation of undigested food, and a barium swallow showing a "bird's beak" narrowing at the gastroesophageal junction. Manometry confirms aperistalsis. What is the primary pathogenesis of his condition?

Accepted Answer

Loss of inhibitory neurons (nitric oxide, VIP) in the oesophageal wall — Primary achalasia results from loss of inhibitory neurons (secreting nitric oxide and VIP) in the oesophageal myenteric plexus, causing incomplete LES relaxation, increased LES tone, and aperistalsis. ---

Question 10

A patient with advanced alcoholic cirrhosis develops sudden massive haematemesis. Emergency endoscopy reveals ruptured oesophageal varices. What is the mortality rate from this first bleeding episode?

Accepted Answer

Approximately 50% despite intervention — Approximately 50% of patients die from the first variceal bleeding episode from direct haemorrhage or hepatic coma from the protein load combined with hypovolaemic shock. ---

Question 11

A 42-year-old male presents after a binge drinking episode with haematemesis. Endoscopy shows linear tears crossing the gastroesophageal junction without perforation into the mediastinum. What distinguishes this from Boerhaave syndrome?

Accepted Answer

Mallory-Weiss tears occur in the stomach while Boerhaave occurs only in the oesophagus — Mallory-Weiss tears are superficial mucosal lacerations that heal spontaneously. Boerhaave syndrome involves transmural perforation leading to mediastinitis — a life-threatening surgical emergency. ---

Question 12

A 55-year-old woman with longstanding GERD undergoes endoscopy showing salmon-pink tongues of mucosa extending above the gastroesophageal junction. Biopsy confirms goblet cells. What is the significance of this finding?

Accepted Answer

Represents Barrett oesophagus with 30–40 fold increased adenocarcinoma risk — Barrett oesophagus is defined by intestinal metaplasia (goblet cells) replacing squamous oesophageal epithelium and confers a 30–40 fold increased risk of oesophageal adenocarcinoma compared to the general population. ---

Question 13

A 28-year-old atopic male with allergic rhinitis and asthma presents with food impaction and dysphagia. Symptoms fail to improve on high-dose PPI. Endoscopic biopsies from the mid-oesophagus show dense eosinophilic infiltration superficially. What is the diagnosis?

Accepted Answer

Eosinophilic oesophagitis — atopic background — Eosinophilic oesophagitis is a chronic immune response characterised by eosinophilic infiltration of the oesophageal mucosa, often associated with atopy. It typically presents with dysphagia and food impaction and does not respond well to PPIs. ---

Question 14

A 70-year-old male with long-standing pernicious anaemia is found to have a gastric polyp on endoscopy. Biopsy shows hyperplastic glands with mild dysplasia. What is the most likely outcome?

Accepted Answer

It is a precursor to gastric adenocarcinoma with increased surveillance required — Patients with pernicious anaemia have an increased risk of gastric adenocarcinoma. Gastric polyps in this setting, especially those with dysplasia, are considered premalignant and require close monitoring and surveillance. ---

Question 15

A 60-year-old female presents with postprandial epigastric pain, nausea, and vomiting, particularly after fatty meals. Abdominal ultrasound is normal. What is the most likely diagnosis?

Accepted Answer

Cholelithiasis and biliary colic — Postprandial epigastric pain, nausea, and vomiting, especially after fatty meals, are classic symptoms of cholelithiasis and biliary colic. While ultrasound is the first-line investigation, it can miss small stones or non-obstructive stones. Further investigations like HIDA scan or MRCP might be needed. ---

Question 16

A 40-year-old male with a history of heavy alcohol use develops severe epigastric pain radiating to the back, nausea, and vomiting. His amylase and lipase are elevated. What is the most likely diagnosis?

Accepted Answer

Acute pancreatitis — Severe epigastric pain radiating to the back, nausea, vomiting, and elevated amylase and lipase levels are classic signs of acute pancreatitis, often precipitated by heavy alcohol use. ---

Question 17

A 25-year-old male presents with fever, jaundice, and RUQ pain after eating raw oysters. AST and ALT are markedly elevated, and bilirubin is also high. What is the most likely infectious agent?

Accepted Answer

Vibrio vulnificus — Eating raw oysters can expose individuals to Vibrio vulnificus, which can cause severe gastroenteritis, wound infections, and life-threatening sepsis, particularly in individuals with liver disease or immunocompromise. While Hepatitis A can also be transmitted via shellfish, the presentation with severe sepsis and rapid deterioration is more characteristic of V. vulnificus. ---

Question 18

A 50-year-old obese female presents with intermittent RUQ pain after fatty meals. Ultrasound shows gallstones but no evidence of inflammation. What is the most appropriate management?

Accepted Answer

Pain management and dietary advice — For asymptomatic or mildly symptomatic gallstones, observation with dietary advice and pain management is often appropriate. Elective cholecystectomy is considered for symptomatic patients or those with specific risk factors, but immediate surgery for uncomplicated biliary colic is not always necessary. ---

Question 19

A 65-year-old male with a history of smoking develops painless jaundice, weight loss, and a palpable non-tender gallbladder (Courvoisier's sign). What is the most likely diagnosis?

Accepted Answer

Pancreatic cancer — Painless jaundice, weight loss, and a palpable gallbladder (Courvoisier's sign) in an elderly male smoker are highly suggestive of pancreatic cancer obstructing the common bile duct. The painless nature is key. While gallstones can cause jaundice, it's usually associated with pain (biliary colic), and Courvoisier's sign is less common. Hepatitis typically presents with constitutional symptoms and less likely a palpable gallbladder. ---

Question 20

A 30-year-old male develops acute hepatitis with elevated transaminases and jaundice. He reports multiple sexual partners and recent unprotected sex. Serological tests reveal HBsAg positive, anti-HBc IgM positive, and anti-HBs negative. What is the most likely diagnosis?

Accepted Answer

Acute Hepatitis B infection — The presence of HBsAg, anti-HBc IgM, and the absence of anti-HBs indicates an acute Hepatitis B infection. Anti-HBc IgM is a marker for recent infection. ---

Question 21

A 50-year-old female with a history of chronic hepatitis C develops ascites and esophageal varices. Liver biopsy shows micronodular cirrhosis. What is the most likely complication leading to this advanced liver disease?

Accepted Answer

Hepatitis B co-infection — While chronic Hepatitis C is a direct cause of cirrhosis, co-infection with Hepatitis B can accelerate the progression to cirrhosis and hepatocellular carcinoma. In the context of already advanced disease, it's a significant factor that would have contributed to the severity and progression. ---

Question 22

A 20-year-old male presents with anorexia, nausea, vomiting, and RUQ pain. He has a history of intravenous drug use and multiple sexual partners. Serological tests are negative for Hepatitis A, B, and C. What is the most likely cause of his symptoms?

Accepted Answer

Drug-induced liver injury — Given the history of intravenous drug use and multiple sexual partners, drug-induced liver injury (DILI) is a strong possibility. While Hepatitis E can cause acute hepatitis, it's typically acquired through contaminated water or food and less common in this demographic. Autoimmune hepatitis is a possibility but less likely without specific autoantibodies. Budd-Chiari syndrome involves hepatic vein obstruction. ---

Question 23

A 60-year-old male with known cirrhosis develops altered mental status, asterixis, and a musty odor to his breath. Lab results show elevated ammonia. What is the most likely diagnosis?

Accepted Answer

Hepatic encephalopathy — Hepatic encephalopathy is a complication of advanced liver disease characterized by neurological dysfunction due to the accumulation of toxins, such as ammonia, in the brain. Asterixis (flapping tremor) and a musty breath odor are classic signs. ---

Question 24

A 45-year-old male with chronic pancreatitis experiences steatorrhea (fatty stools) and weight loss. What is the most likely cause of these symptoms?

Accepted Answer

Malabsorption due to exocrine pancreatic insufficiency — Chronic pancreatitis leads to destruction of the exocrine pancreas, impairing the production of digestive enzymes. This results in malabsorption of fats, proteins, and carbohydrates, leading to steatorrhea and weight loss. ---

Question 25

A 70-year-old female with a history of constipation presents with LLQ pain, fever, and leukocytosis. CT scan shows a thickened segment of the colon with pericolic fat stranding. What is the most likely diagnosis?

Accepted Answer

Diverticulitis — Left lower quadrant pain, fever, leukocytosis, and CT findings of a thickened colon segment with pericolic fat stranding are classic for acute diverticulitis, a common condition in the elderly, especially those with a history of constipation. ---

Question 26

A 30-year-old male has a 2-week history of watery diarrhoea, abdominal cramping, and fever. Stool studies reveal leukocytes and lactoferrin. What is the most likely pathogen?

Accepted Answer

Shigella — Bloody diarrhoea with fever and stool leukocytes/lactoferrin suggests an invasive bacterial pathogen. Shigella is a common cause of bacillary dysentery presenting with these symptoms. While Campylobacter and E. coli O157:H7 can cause bloody diarrhoea, Shigella is highly invasive and frequently associated with fever and inflammatory markers. ---

Question 27

A 55-year-old male with a history of peptic ulcer disease presents with sudden onset of severe upper abdominal pain that radiates to the back, and he is hypotensive and rigid. What is the most likely diagnosis?

Accepted Answer

Perforated peptic ulcer — Sudden onset of severe upper abdominal pain, rigidity, and hypotension in a patient with peptic ulcer disease strongly suggests a perforated peptic ulcer, a surgical emergency. ---

Question 28

A 68-year-old male with chronic constipation develops acute, severe abdominal pain, distention, and obstipation. Plain abdominal X-ray shows a dilated loop of colon with a characteristic "coffee bean" sign. What is the most likely diagnosis?

Accepted Answer

Volvulus (sigmoid or cecal) — Acute severe abdominal pain, distention, and obstipation with a dilated loop of colon and a "coffee bean" sign on X-ray are highly suggestive of sigmoid or cecal volvulus. ---

Question 29

A 40-year-old female presents with chronic diarrhoea, weight loss, and abdominal pain. Biopsy of the small intestine shows villous atrophy and intraepithelial lymphocytosis. She is positive for anti-tissue transglutaminase (anti-tTG) antibodies. What is the diagnosis?

Accepted Answer

Celiac disease — Chronic diarrhoea, weight loss, villous atrophy, increased intraepithelial lymphocytes, and positive anti-tTG antibodies are diagnostic of celiac disease. ---

Question 30

A 25-year-old female develops severe watery diarrhoea after a course of antibiotics. Stool studies are positive for C. difficile toxin. What is the most appropriate initial treatment?

Accepted Answer

Metronidazole — For initial episodes of C. difficile infection, oral metronidazole is generally the preferred treatment, especially if the infection is not severe. Oral vancomycin is reserved for severe cases or when metronidazole is contraindicated or ineffective. ---

Question 31

A 60-year-old male presents with painless jaundice, dark urine, and pale stools. He has a history of chronic pancreatitis. Which diagnostic modality is most likely to identify the cause of his jaundice?

Accepted Answer

Endoscopic retrograde cholangiopancreatography (ERCP) — Given the history of chronic pancreatitis, a pancreatic head mass causing biliary obstruction is highly suspected. ERCP allows for visualization and potential intervention (like stenting) of the biliary tree and can also identify pancreatic ductal abnormalities. ---

Question 32

A 35-year-old female with a history of Irritable Bowel Syndrome (IBS) develops sudden onset of severe LLQ pain with fever and leukocytosis. What is the most likely new diagnosis?

Accepted Answer

Diverticulitis — While IBS can cause LLQ pain, the acute onset of severe pain, fever, and leukocytosis suggests an inflammatory process like diverticulitis, which is more common in this age group and location than appendicitis (typically RLQ) or UC/Crohn's flares presenting with these acute symptoms. ---

Question 33

A 50-year-old male presents with epigastric pain that is relieved by food and recurs 2-3 hours after meals. He denies NSAID use or alcohol abuse. What is the most likely diagnosis?

Accepted Answer

Peptic ulcer disease (duodenal ulcer) — Epigastric pain that is relieved by food and recurs 2-3 hours after meals is characteristic of a duodenal ulcer, a common manifestation of peptic ulcer disease. Gastric ulcers tend to be worsened by food. ---

Question 34

A 60-year-old female with a history of long-standing GERD undergoes an upper endoscopy. Biopsies from the distal esophagus show intestinal metaplasia with goblet cells. What is the significance of this finding?

Accepted Answer

Barrett's esophagus with increased risk of adenocarcinoma — The presence of intestinal metaplasia with goblet cells in the esophagus is known as Barrett's esophagus, which is a premalignant condition associated with a significantly increased risk of esophageal adenocarcinoma. ---

Question 35

A 70-year-old male presents with a 2-month history of unexplained weight loss, fatigue, and vague abdominal discomfort. Colonoscopy reveals a thickened, stenotic segment in the sigmoid colon with irregular mucosa. Biopsies show adenocarcinoma. What is the most likely reason for his symptoms?

Accepted Answer

Obstruction and inflammation from the tumor — A stenotic colon cancer can cause partial obstruction leading to symptoms like abdominal discomfort, cramping, and changes in bowel habits. Weight loss and fatigue can be due to chronic blood loss leading to anemia, or the systemic effects of cancer. While anemia is common, obstruction is a direct mechanical effect of a stenotic tumor. ---

Question 36

A 3-month-old infant presents with projectile vomiting and a palpable olive-shaped mass in the epigastrium. What is the most likely diagnosis?

Accepted Answer

Pyloric stenosis — Projectile vomiting and a palpable olive-shaped mass in the epigastrium in an infant are classic signs of hypertrophic pyloric stenosis. ---

Question 37

A 5-year-old child presents with fever, vomiting, and right lower quadrant abdominal pain. Tenderness is maximal at McBurney's point. What is the most likely diagnosis?

Accepted Answer

Appendicitis — Fever, vomiting, and right lower quadrant abdominal pain with maximal tenderness at McBurney's point are classic symptoms and signs of acute appendicitis in children. ---

Question 38

A 6-month-old infant presents with intermittent episodes of crying, pallor, and drawing up of the legs, followed by passage of currant jelly stools. What is the most likely diagnosis?

Accepted Answer

Intussusception — Intermittent crying, pallor, drawing up of legs, and passage of currant jelly stools (blood and mucus) are classic signs of intussusception, a condition where one segment of the intestine telescopes into another. ---

Question 39

A 40-year-old female develops watery diarrhoea, abdominal bloating, and gas after consuming dairy products. Lactose breath hydrogen test is positive. What is the most likely diagnosis?

Accepted Answer

Lactose intolerance — Symptoms of watery diarrhoea, bloating, and gas after dairy consumption, along with a positive lactose breath hydrogen test, are diagnostic of lactose intolerance. ---

Question 40

A 50-year-old male presents with chronic, non-bloody diarrhoea and diffuse abdominal pain. Colonoscopy is normal, but biopsies show a thickened subepithelial collagen band. What is the diagnosis?

Accepted Answer

Collagenous colitis — Chronic non-bloody diarrhoea with a normal colonoscopy and a thickened subepithelial collagen band on biopsy is characteristic of collagenous colitis. ---

Question 41

A 3-year-old child develops a sudden onset of severe abdominal pain, fever, and vomiting. Abdominal examination reveals generalized tenderness and rigidity. Plain abdominal X-ray shows a distended small bowel with air-fluid levels and no gas in the colon. What is the most likely diagnosis?

Accepted Answer

Adhesions causing small bowel obstruction — Sudden severe abdominal pain, fever, vomiting, generalized tenderness, rigidity, distended small bowel with air-fluid levels, and no colonic gas strongly suggest a small bowel obstruction, often caused by adhesions in this age group. Volvulus can cause obstruction but often has a more specific appearance on imaging. Intussusception typically has intermittent symptoms and specific stool findings. Appendicitis is usually localized to the RLQ. ---

Question 42

A 60-year-old male with a history of H. pylori infection and peptic ulcer disease undergoes an upper endoscopy. Biopsy of a gastric ulcer shows intestinal metaplasia and dysplasia. What is the most concerning implication of this finding?

Accepted Answer

Increased risk of gastric adenocarcinoma — Intestinal metaplasia and dysplasia in a gastric ulcer, especially in the context of H. pylori infection, are significant risk factors for the development of gastric adenocarcinoma. ---

Question 43

A 70-year-old female presents with chronic constipation, LLQ pain, and intermittent rectal bleeding. Colonoscopy reveals multiple diverticula in the sigmoid colon. What is the most likely complication she is experiencing?

Accepted Answer

Bleeding — While diverticulitis, perforation, and obstruction are complications of diverticular disease, intermittent rectal bleeding, especially in an elderly patient with known diverticula, is most commonly due to a diverticular bleed. ---

Question 44

A 45-year-old male presents with right upper quadrant pain, fever, and jaundice, along with a palpable, distended gallbladder. Lab results show elevated alkaline phosphatase and direct bilirubin. What is the most likely diagnosis?

Accepted Answer

Choledocholithiasis with cholangitis — The combination of right upper quadrant pain, fever, jaundice, elevated alkaline phosphatase, direct bilirubin, and a palpable distended gallbladder is characteristic of choledocholithiasis (stones in the common bile duct) complicated by cholangitis (infection of the bile ducts). ---

Question 45

A 20-year-old female with a history of irritable bowel syndrome (IBS) develops new onset of inflammatory bowel disease (IBD). Which symptom is most indicative of IBD over IBS?

Accepted Answer

Rectal bleeding — Rectal bleeding is a hallmark symptom that differentiates inflammatory bowel disease (like ulcerative colitis) from irritable bowel syndrome, which typically does not involve bleeding. ---

Question 46

A 50-year-old male presents with a history of chronic diarrhoea, weight loss, and abdominal pain. Small bowel biopsy shows villous atrophy, increased intraepithelial lymphocytes, and positive anti-tTG antibodies. What is the most appropriate long-term management?

Accepted Answer

Gluten-free diet — The diagnosis of celiac disease, confirmed by biopsy and serology, requires a lifelong gluten-free diet to manage symptoms and prevent complications. ---

Question 47

A 70-year-old male with a history of smoking and alcohol abuse develops progressive dysphagia to solids and then liquids. A barium swallow shows a dilated esophagus above a narrow, aperistaltic segment. What is the most likely diagnosis?

Accepted Answer

Achalasia — Progressive dysphagia to solids and liquids, a dilated esophagus above a narrow segment, and aperistalsis on manometry are characteristic findings of achalasia, a motility disorder o

MCQ: GASTROINTESTINAL PATHOLOGY — 60 MCQs (Redistributed...

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