UWorld UWorld System-Based Pathology 1 — Questions and Answers
Question 1: In UWorld cardiology content, what ECG finding is most associated with Wolff-Parkinson-White (WPW) syndrome?
- Short PR interval with a delta wave (slurred upstroke of the QRS) (Correct answer)
- Prolonged PR interval with dropped QRS complexes
- ST elevation in all leads simultaneously
- Peaked T waves with widened QRS
Correct answer: Short PR interval with a delta wave (slurred upstroke of the QRS)
WPW features a short PR interval due to accessory pathway conduction and a delta wave from ventricular pre-excitation, both hallmarks tested extensively in UWorld cardiology questions.
Question 2: Which pulmonary condition in UWorld is classically associated with the radiographic finding of 'honeycomb lung' on CT?
- Idiopathic pulmonary fibrosis (IPF) (Correct answer)
- Pulmonary embolism
- Lobar pneumonia
- Sarcoidosis
Correct answer: Idiopathic pulmonary fibrosis (IPF)
Honeycombing on CT with a subpleural, basal-predominant pattern is the hallmark of IPF, representing end-stage fibrosis with cystic airspace formation.
Question 3: In UWorld nephrology, what is the classic urinalysis finding in acute tubular necrosis (ATN)?
- Muddy brown granular casts (Correct answer)
- RBC casts
- Waxy casts
- WBC casts
Correct answer: Muddy brown granular casts
Muddy brown granular casts in the urine are pathognomonic for ATN, resulting from sloughed tubular epithelial cells in the setting of ischemic or nephrotoxic injury.
Question 4: What UWorld hematology concept explains why sickle cell patients are functionally asplenic?
- Repeated splenic infarctions from sickling cause autosplenectomy, leaving patients susceptible to encapsulated organisms (Correct answer)
- Sickle cell patients have surgically removed spleens at birth
- The spleen is absent due to a developmental defect in sickle cell disease
- Splenomegaly compresses splenic vasculature, reducing function
Correct answer: Repeated splenic infarctions from sickling cause autosplenectomy, leaving patients susceptible to encapsulated organisms
Repeated vaso-occlusive episodes in the spleen cause progressive infarction and fibrosis (autosplenectomy), rendering patients susceptible to infections with encapsulated bacteria like Streptococcus pneumoniae.
Question 5: In UWorld endocrinology, what distinguishes Cushing's disease from ectopic ACTH syndrome?
- Cushing's disease is caused by a pituitary adenoma secreting ACTH, while ectopic ACTH is secreted by non-pituitary tumors like small cell lung cancer (Correct answer)
- Cushing's disease has lower cortisol levels than ectopic ACTH syndrome
- Cushing's disease causes bilateral adrenal hyperplasia while ectopic ACTH does not
- They are clinically identical and require genetic testing to distinguish
Correct answer: Cushing's disease is caused by a pituitary adenoma secreting ACTH, while ectopic ACTH is secreted by non-pituitary tumors like small cell lung cancer
Cushing's disease specifically refers to pituitary ACTH overproduction, while ectopic ACTH comes from tumors like small cell lung carcinoma; both cause bilateral adrenal hyperplasia, but the source differs.
Question 6: What UWorld gastroenterology finding is characteristic of celiac disease on small bowel biopsy?
- Villous atrophy with crypt hyperplasia and increased intraepithelial lymphocytes (Correct answer)
- Non-caseating granulomas throughout all layers of the bowel wall
- Pseudomembranes overlying colonic mucosa
- Cobblestoning with skip lesions in the terminal ileum
Correct answer: Villous atrophy with crypt hyperplasia and increased intraepithelial lymphocytes
Celiac disease causes villous blunting with compensatory crypt hyperplasia and increased intraepithelial lymphocytes, triggered by gluten-induced immune damage to the small intestinal mucosa.
UWorld UWorld System-Based Pathology 1
In UWorld cardiology content, what ECG finding is most associated with Wolff-Parkinson-White (WPW) syndrome?