Internal Medicine Shelf Practice Exam. Correct Answers at en

1. A 70-year-old man is brought to the hospital with a three-day history of fever, productive cough, and confusion. Chest X-ray reveals a right lower lobe consolidation. What is the most likely etiological agent responsible for his symptoms?

A) Legionella pneumophila

B) Streptococcus pneumoniae

C) Mycoplasma pneumoniae

D) Staphylococcus aureus

E) Chlamydophila pneumoniae

2. A 56-year-old woman presents with a two-week history of progressive shortness of breath and bilateral leg swelling. Examination reveals elevated jugular venous pressure, hepatomegaly, and lower limb edema. Echocardiography shows a dilated right ventricle. What is the most likely diagnosis?

A) Constrictive pericarditis

B) Pulmonary embolism

C) Cor pulmonale

D) Congestive heart failure

E) Pericardial effusion

3. A 45-year-old man with a history of alcohol abuse presents with upper abdominal pain radiating to his back and nausea for the past 24 hours. His serum lipase is three times the upper limit of normal. What is the most likely diagnosis?

A) Cholecystitis

B) Peptic ulcer disease

C) Acute pancreatitis

D) Gastric carcinoma

E) Esophagitis

4. A 60-year-old man with a history of smoking presents with persistent cough, weight loss, and hemoptysis. A chest X-ray shows a mass in the right upper lobe. What is the most likely diagnosis?

A) Bronchiectasis

B) Pneumonia

C) Lung abscess

D) Tuberculosis

E) Lung cancer

5. A 35-year-old woman presents with a one-week history of multiple painful mouth ulcers. Examination reveals a genital ulcer and erythematous papules on both her palms and soles. What is the most likely diagnosis?

A) Herpes simplex virus infection

B) Behcet disease

C) Syphilis

D) Gonorrhea

E) Chancroid

6. A 64-year-old man presents with new-onset atrial fibrillation and heart failure. His ECG shows a small QRS complex. What is the most likely underlying cause?

A) Hyperthyroidism

B) Hypothyroidism

C) Hyperkalemia

D) Hypokalemia

E) Amyloidosis

7. A 52-year-old woman presents with polyuria, polydipsia, and nocturia. Laboratory tests reveal hypercalcemia and decreased serum phosphate. What is the most likely diagnosis?

A) Hyperparathyroidism

B) Hypoparathyroidism

C) Vitamin D toxicity

D) Multiple myeloma

E) Hyperthyroidism

8. A 50-year-old man presents with upper abdominal pain, jaundice, and weight loss. CT scan shows a mass at the head of the pancreas. What is the most likely diagnosis?

A) Acute pancreatitis

B) Pancreatic cancer

C) Gallstones

D) Gastric carcinoma

E) Cholangiocarcinoma

9. A 25-year-old woman presents with recent weight gain, fatigue, and constipation. On examination, her skin is dry, and she has a slow relaxation phase of deep tendon reflexes. What is the most likely diagnosis?

A) Hypothyroidism

B) Hyperthyroidism

C) Cushing's syndrome

D) Addison's disease

E) Pheochromocytoma

10. A 65-year-old woman presents with dyspnea and fatigue. Her Hb is 9 g/dL, MCV is 110 fL, and peripheral smear shows hypersegmented neutrophils. What is the most likely diagnosis?

A) Iron deficiency anemia

B) Thalassemia

C) Anemia of chronic disease

D) Vitamin B12 deficiency

E) Folate deficiency

11. A 62-year-old woman with a history of rheumatoid arthritis presents with fatigue and shortness of breath. Laboratory tests reveal a hemoglobin of 9.8 g/dL and normal iron studies. What is the most likely cause of her anemia?

A) Iron deficiency anemia

B) Anemia of chronic disease

C) Pernicious anemia

D) Aplastic anemia

E) Hemolytic anemia

12. A 55-year-old man presents with fatigue, pallor, and exertional dyspnea. Labs show a microcytic anemia with decreased iron levels. What is the most appropriate next step?

A) Iron supplementation

B) Colonoscopy

C) Bone marrow biopsy

D) Transfusion of packed red cells

E) Dietary counseling

13. A 72-year-old man presents with weight loss, fatigue, and night sweats. On examination, he has palpable, non-tender lymph nodes in the cervical, axillary, and inguinal regions. What is the most likely diagnosis?

A) Hodgkin's lymphoma

B) Non-Hodgkin's lymphoma

C) Acute lymphoblastic leukemia

D) Chronic myeloid leukemia

E) Metastatic carcinoma

14. A 58-year-old man presents with chest pain radiating to the left arm. EKG shows ST-segment elevation in leads II, III, and aVF. What artery is most likely occluded?

A) Left anterior descending artery

B) Left circumflex artery

C) Right coronary artery

D) Posterior descending artery

E) Anterior interventricular artery

15. A 40-year-old woman presents with a three-day history of worsening right lower quadrant pain. She has nausea but no vomiting. On examination, there is tenderness at McBurney's point. What is the most likely diagnosis?

A) Diverticulitis

B) Appendicitis

C) Ectopic pregnancy

D) Ovarian torsion

E) Pyelonephritis

16. A 50-year-old woman presents with a 6-month history of amenorrhea, hot flashes, and night sweats. What is the most likely diagnosis?

A) Premature ovarian failure

B) Menopause

C) Pregnancy

D) Polycystic ovary syndrome

E) Hypothalamic-pituitary dysfunction

17. A 45-year-old man presents with pain and stiffness in his lower back that improves with activity and worsens at rest. He also notes that the pain often wakes him up at night. What is the most likely diagnosis?

A) Lumbar disk herniation

B) Osteoarthritis

C) Ankylosing spondylitis

D) Spinal stenosis

E) Sciatica

18. A 60-year-old woman presents with fatigue, weight loss, and tingling in her hands and feet. Labs reveal a macrocytic anemia, and peripheral smear shows hypersegmented neutrophils. What is the most likely cause of her symptoms?

A) Iron deficiency anemia

B) Folate deficiency

C) Vitamin B12 deficiency

D) Thalassemia

E) Anemia of chronic disease

19. A 35-year-old woman presents with a 3-day history of painful vision loss in her left eye. On examination, her visual acuity is decreased, and there is an afferent pupillary defect. What is the most likely diagnosis?

A) Glaucoma

B) Optic neuritis

C) Retinal detachment

D) Macular degeneration

E) Cataract

20. A 55-year-old man with a history of alcohol abuse presents with epigastric pain radiating to the back, nausea, and vomiting. Lab studies show elevated lipase and amylase. What is the most likely diagnosis?

A) Acute pancreatitis

B) Peptic ulcer disease

C) Cholecystitis

D) Gastric carcinoma

E) Hepatitis

21. A 70-year-old man presents with gradually worsening memory loss over the past year. His wife reports that he has been increasingly misplacing items and occasionally gets lost in familiar places. What is the most likely diagnosis?

A) Normal aging

B) Alzheimer's disease

C) Vascular dementia

D) Frontotemporal dementia

E) Lewy body dementia

22. A 60-year-old woman presents with severe pain in her right big toe. Physical examination reveals a swollen, erythematous, and tender joint. What is the most likely diagnosis?

A) Gout

B) Osteoarthritis

C) Rheumatoid arthritis

D) Septic arthritis

E) Pseudogout

23. A 50-year-old man with a history of hepatitis C presents with ascites, jaundice, and confusion. What is the most likely diagnosis?

A) Alcoholic hepatitis

B) Cholelithiasis

C) Cirrhosis

D) Hepatocellular carcinoma

E) Pancreatitis

24. A 45-year-old woman presents with a palpable mass in her right breast. Mammography confirms the presence of a 2 cm mass. What is the most appropriate next step?

A) Repeat mammography in 6 months

B) Breast ultrasound

C) Fine needle aspiration

D) Core needle biopsy

E) MRI of the breast

25. A 25-year-old man presents with painful urination and a purulent penile discharge. His only sexual partner is symptom-free. What is the most likely causative agent?

A) Chlamydia trachomatis

B) Neisseria gonorrhoeae

C) Trichomonas vaginalis

D) Herpes simplex virus

E) Human papillomavirus

26. A 65-year-old man presents with a complaint of difficulty swallowing solids and liquids for the past six months. He denies any significant weight loss. The barium swallow test shows a dilated esophagus with an absence of peristalsis and a 'bird's beak' appearance at the lower esophagus. What is the most likely diagnosis?

A) Achalasia

B) Esophageal stricture

C) Gastroesophageal reflux disease (GERD)

D) Esophageal cancer

E) Peptic stricture

27. A 32-year-old woman presents with a complaint of exertional dyspnea for the past two months. She has a history of systemic lupus erythematosus (SLE). On examination, there are decreased breath sounds and dullness to percussion at the lung bases. Chest X-ray shows blunting of the costophrenic angles bilaterally. What is the most likely diagnosis?

A) Pneumonia

B) Pulmonary embolism

C) Pneumothorax

D) Pleural effusion

E) Interstitial lung disease

28. A 72-year-old man presents with progressive memory loss over the past year. His wife reports that he often forgets conversations and misplaces items around the house. His medical history is unremarkable, and his neurological examination is normal. His MRI brain shows cortical atrophy. What is the most likely diagnosis?

A) Normal pressure hydrocephalus

B) Vascular dementia

C) Alzheimer's disease

D) Lewy body dementia

E) Frontotemporal dementia

29 A 50-year-old man with a history of HIV presents with fever, headache, and stiff neck. Cerebrospinal fluid (CSF) analysis shows 100 white cells (95% lymphocytes), low glucose, and high protein. Gram stain of the CSF shows no organisms. Which is the most likely diagnosis?

A) Cryptococcal meningitis

B) Bacterial meningitis

C) Viral meningitis

D) Tuberculous meningitis

E) Neurosyphilis

30. A 40-year-old woman presents with polyuria, polydipsia, and blurred vision. Her blood glucose level is 500 mg/dL, and urinalysis reveals glucose and ketones. What is the most likely diagnosis?

A) Type 1 diabetes mellitus

B) Type 

2 diabetes mellitus

C) Diabetic ketoacidosis

D) Hyperosmolar hyperglycemic state

E) Hypoglycemia

31. A 75-year-old woman presents with a two-week history of worsening fatigue, lack of appetite, and depression. She reports a 10-pound unintentional weight loss over the past 2 months. On physical examination, she appears cachectic, and there is mild tenderness in the right upper quadrant of the abdomen. CT scan of the abdomen shows a mass in the head of the pancreas. Which of the following is the most likely diagnosis?

A) Chronic pancreatitis

B) Pancreatic adenocarcinoma

C) Gallstones

D) Liver cirrhosis

E) Hepatitis

32. A 28-year-old man presents with a two-day history of cough, fever, and pleuritic chest pain. Chest x-ray shows a lobar consolidation in the right lower lobe. Which of the following is the most likely causative organism?

A) Mycoplasma pneumoniae

B) Streptococcus pneumoniae

C) Staphylococcus aureus

D) Klebsiella pneumoniae

E) Haemophilus influenzae

33. A 64-year-old woman presents with a 6-month history of dyspnea and non-productive cough. She has never smoked and has no significant occupational exposures. Pulmonary function tests show a reduced diffusion capacity. High-resolution CT scan reveals ground-glass opacities and traction bronchiectasis. What is the most likely diagnosis?

A) Chronic obstructive pulmonary disease

B) Asthma

C) Idiopathic pulmonary fibrosis

D) Pneumonia

E) Lung cancer

34. A 70-year-old man with a 30-pack-year smoking history presents with a persistent cough and unintentional weight loss. Chest CT shows a mass in the right upper lobe. Biopsy of the mass shows small cells with scant cytoplasm and dense chromatin. What is the most likely diagnosis?

A) Small cell lung cancer

B) Non-small cell lung cancer

C) Tuberculosis

D) Pneumonia

E) Sarcoidosis

35. A 60-year-old woman presents with increasing fatigue and jaundice. She denies alcohol use and has no history of liver disease. Her total bilirubin is 5.0 mg/dL (normal 0.3-1.0 mg/dL), direct bilirubin is 3.5 mg/dL (normal 0-0.3 mg/dL), and alkaline phosphatase is 400 U/L (normal 40-150 U/L). What

is the most likely cause of this patient's symptoms?

A) Viral hepatitis

B) Alcoholic hepatitis

C) Cirrhosis

D) Cholestasis

E) Hemolytic anemia

36. A 55-year-old man with a history of type 2 diabetes and hypertension presents with a week-long history of feeling unwell, fatigue, and decreased appetite. His temperature is 38.0°C (100.4°F), blood pressure is 120/80 mm Hg, pulse is 90/min, and respirations are 18/min. Physical examination is unremarkable except for a foul-smelling ulcer on the sole of his right foot. Blood cultures grow gram-positive cocci in clusters. What is the most likely cause of this patient's symptoms?

A) Diabetic ketoacidosis

B) Hyperosmolar hyperglycemic state

C) Hypoglycemia

D) Diabetic foot infection

E) Necrotizing fasciitis

37. A 50-year-old woman presents to the clinic with a two-month history of progressive dyspnea and orthopnea. She has a history of type 2 diabetes and hypertension. On physical examination, you notice jugular venous distension and bilateral pitting edema. Chest radiograph shows cardiomegaly. Which of the following is the most likely diagnosis?

A) Acute myocardial infarction

B) Chronic obstructive pulmonary disease (COPD)

C) Pulmonary embolism

D) Congestive heart failure (CHF)

E) Pneumonia

38. A 60-year-old man presents with sudden onset of severe tearing chest pain that radiates to the back. His blood pressure is 180/100 mmHg, and pulse is 110/min. Examination reveals a diastolic murmur best heard over the right sternal border. CT scan of the chest shows an aortic dissection involving the ascending aorta. What is the most likely diagnosis?

A) Acute myocardial infarction

B) Thoracic aortic aneurysm

C) Stanford Type A aortic dissection

D) Stanford Type B aortic dissection

E) Pulmonary embolism

39. A 40-year-old woman presents with a 2-month history of weight gain, fatigue, and constipation. She also reports feeling cold all the time. On physical examination, she has dry skin, bradycardia, and delayed deep tendon reflexes. Laboratory tests show a low serum T4 and a high TSH. What is the most likely diagnosis?

A) Hyperthyroidism

B) Hypothyroidism

C) Thyroiditis

D) Thyroid nodules

E) Thyroid cancer

40. A 45-year-old man presents with a one-week history of diarrhea and cramping abdominal pain. He reports recently eating at a seafood restaurant. Stool culture grows Vibrio parahaemolyticus. What is the most likely cause of this patient's symptoms?

A) Inflammatory bowel disease

B) Irritable bowel syndrome

C) Food poisoning

D) Gastroenteritis

E) Diverticulitis

Answers: 

1. Answer: B) Streptococcus pneumoniae. S. pneumoniae is the most common cause of community-acquired pneumonia, especially in older adults. The patient's symptoms and radiographic findings support this diagnosis.

2. Answer: C) Cor pulmonale. The patient's symptoms and echocardiography findings suggest chronic right heart failure secondary to a lung disorder, known as cor pulmonale. 

3. Answer: C) Acute pancreatitis. The patient's alcohol history, symptoms, and increased serum lipase make acute pancreatitis the most likely diagnosis.

4. Answer: E) Lung cancer. The patient's smoking history, symptoms, and radiographic findings make lung cancer the most likely diagnosis.

5. Answer: C) Syphilis. The patient's symptoms are suggestive of secondary syphilis, which can present with mucocutaneous lesions, including mouth and genital ulcers and a rash often involving the palms and soles.

6. Answer: E) Amyloidosis. The combination of new-onset atrial fibrillation, heart failure, and a small QRS complex suggests cardiac amyloidosis.

7. Answer: A) Hyperparathyroidism. The classic symptoms of 'stones, bones, abdominal groans, and psychic moans' point towards hyperparathyroidism.

8. Answer: B) Pancreatic cancer. The combination of upper abdominal pain, jaundice, and weight loss suggests a malignant process involving the head of the pancreas.

9. Answer: A) Hypothyroidism. The combination of weight gain, fatigue, constipation, dry skin, and slowed reflexes are consistent with hypothyroidism.

10. Answer: D) Vitamin B12 deficiency. Macrocytic anemia with hypersegmented neutrophils suggests a deficiency of Vitamin B12 or Folate. Neurological symptoms often differentiate B12 deficiency from Folate deficiency.

11. Answer: B) Anemia of chronic disease. Given her history of a chronic inflammatory condition (rheumatoid arthritis), anemia of chronic disease (or anemia of inflammation) is the most likely diagnosis.

12. Answer: B) Colonoscopy. In men and post-menopausal women, gastrointestinal bleeding due to colorectal cancer or other conditions is a common cause of iron deficiency anemia. A colonoscopy is an appropriate next step.

13. Answer: B) Non-Hodgkin's lymphoma. The clinical picture of generalized, non-tender lymphadenopathy, along with B symptoms (weight loss, fatigue, night sweats), suggests a diagnosis of Non-Hodgkin's lymphoma.

14. Answer: C) Right coronary artery. EKG changes in leads II, III, and aVF suggest an inferior wall myocardial infarction, typically caused by occlusion of the right coronary artery.

15. Answer: B) Appendicitis. The patient's presentation of right lower quadrant pain and tenderness at McBurney's point is suggestive of acute appendicitis.

16. Answer: B) Menopause. Given her age and symptoms, natural menopause is the most likely diagnosis.

17. Answer: C) Ankylosing spondylitis. The patient's symptoms of inflammatory back pain, improved by activity and worse at rest or at night, are suggestive of ankylosing spondylitis.

18. Answer: C) Vitamin B12 deficiency. Her symptoms, combined with macrocytic anemia and hypersegmented neutrophils, suggest vitamin B12 deficiency, which can also cause neurological symptoms like peripheral neuropathy.

19. Answer: B) Optic neuritis. Sudden, painful vision loss with an afferent pupillary defect suggests optic neuritis.

20. Answer: A) Acute pancreatitis. Given his history of alcohol abuse and the presentation of epigastric pain radiating to the back, combined with the lab findings, acute pancreatitis is the most likely diagnosis.

21. Answer: B) Alzheimer's disease. Gradual and progressive memory loss, along with problems navigating familiar places, suggest a diagnosis of Alzheimer's disease.

22. Answer: A) Gout. The presentation of an acutely painful, red, swollen joint, particularly the big toe (podagra), is characteristic of gout.

23. Answer: C) Cirrhosis. Given his history of hepatitis C and the presence of ascites, jaundice, and hepatic encephalopathy (indicated by confusion), the most likely diagnosis is cirrhosis.

24. Answer: D) Core needle biopsy. When a palpable breast mass is detected and confirmed on mammography, a core needle biopsy is typically the next step for definitive diagnosis.

25. Answer: B) Neisseria gonorrhoeae. The presentation of dysuria and purulent penile discharge is most consistent with gonorrhea.

26. Answer: A) Achalasia. Achalasia is characterized by the loss of esophageal peristalsis and impaired relaxation of the lower esophageal sphincter, often causing symptoms of dysphagia for both solids and liquids. A 'bird's beak' sign is typically observed on barium swallow imaging.

27. Answer: D) Pleural effusion. Patients with SLE often develop pleural effusion, which is characterized by dyspnea, decreased breath sounds, and dullness to percussion at the lung bases.

28. Answer: C) Alzheimer's disease. The patient's symptoms of progressive memory loss and imaging findings of cortical atrophy are most consistent with Alzheimer's disease.

29. Answer: A) Cryptococcal meningitis. In patients with HIV, the presence of fever, headache, and stiff neck, along with a lymphocytic predominance on CSF analysis and negative Gram stain, suggest cryptococcal meningitis.

30. Answer: C) Diabetic ketoacidosis. The symptoms of polyuria, polydipsia, and blurred vision, along with a high blood glucose level and the presence of ketones in the urine, are indicative of diabetic ketoacidosis, an acute complication of diabetes.

31. Answer: B) Pancreatic adenocarcinoma. The patient's clinical picture of fatigue, anorexia, depression, weight loss, and a mass in the pancreas on imaging is suggestive of pancreatic adenocarcinoma, a malignancy that commonly presents with these symptoms due to its late presentation.

32. Answer: B) Streptococcus pneumoniae. The patient's clinical presentation and imaging findings are most suggestive of a typical pneumonia, most commonly caused by Streptococcus pneumoniae.

33. Answer: C) Idiopathic pulmonary fibrosis. The combination of dyspnea, non-productive cough, reduced diffusion capacity, and imaging findings of ground-glass opacities and traction bronchiectasis is consistent with idiopathic pulmonary fibrosis.

34. Answer: A) Small cell lung cancer. The patient's smoking history, symptoms, imaging findings, and biopsy results are most consistent with small cell lung cancer, a highly aggressive form of lung cancer.

35. Answer: D) Cholestasis. The patient's laboratory results show an obstructive pattern with an elevated direct (conjugated) bilirubin and alkaline phosphatase, indicating cholestasis, which can present with fatigue and jaundice.

36. Answer: D) Diabetic foot infection. The foul-smelling ulcer on his foot and blood cultures growing gram-positive cocci (likely Staphylococcus aureus) indicate a diabetic foot infection.

37. Answer: D) Congestive heart failure (CHF). The patient's symptoms of progressive dyspnea and orthopnea along with the physical examination findings of jugular venous distension and bilateral pitting edema, and a chest radiograph showing cardiomegaly are suggestive of CHF.

38. Answer: C) Stanford Type A aortic dissection. The sudden onset of severe tearing chest pain radiating to the back, hypertension, a diastolic murmur suggestive of aortic insufficiency (a common finding in aortic dissection), and a CT scan showing an aortic dissection involving the ascending aorta are all indicative of Stanford Type A aortic dissection.

39. Answer: B) Hypothyroidism. The patient's symptoms, physical examination findings, and lab results (low T4 and high TSH) are all indicative of hypothyroidism.

40. Answer: C) Food poisoning. The patient's recent history of eating at a seafood restaurant and stool culture positive for Vibrio parahaemolyticus, a common cause of seafood-related food poisoning, suggest this diagnosis.