In which of the following cases is dehydration more likely to occur?

Correct Answer: B

Rationale: Dehydration is more likely to occur in a 50-year-old man who is morbidly obese due to the increased risk of conditions like diabetes and heart disease that can lead to fluid imbalances. Being morbidly obese can also strain the body's systems, increasing the need for water. The other choices are less likely to experience dehydration as a primary concern. While being a bodybuilder may require strict hydration practices, dehydration is more prevalent in individuals with conditions like obesity.

Correct Answer: D

Rationale: Palpable kidneys are a common clinical manifestation in patients with polycystic kidney disease due to the enlarged kidneys with multiple cysts. Suprapubic pain is not typically associated with this condition. Periorbital edema is more commonly seen in conditions like nephrotic syndrome. A low serum creatinine level is not a typical finding in renal impairment, as impaired kidneys usually lead to an elevated serum creatinine level.

Correct Answer: C

Rationale: In nephritic syndrome, the presence of red blood cell casts in the urine is a characteristic finding, reflecting glomerular inflammation and damage. This differentiates it from nephrotic syndrome, where red blood cell casts are typically absent. Choice A is incorrect because nephritic syndrome usually presents with less albuminuria compared to nephrotic syndrome. Choice B is incorrect as hematuria is a common feature of nephritic syndrome. Choice D is incorrect as hypoalbuminemia is more commonly associated with nephrotic syndrome.

Correct Answer: D

Rationale: The correct answer is that ductal carcinoma in situ is characterized by malignant cells that have not invaded the stroma, making it a cancer precursor with a higher risk for invasive cancer compared to lobular carcinoma in situ. Choice A is incorrect because ductal carcinoma in situ is more common than lobular carcinoma in situ. Choice B is incorrect as it only partially describes ductal carcinoma in situ without mentioning its potential for progression to invasive cancer. Choice C is incorrect because it does not capture the complete characteristics of ductal carcinoma in situ, which include the risk for invasive cancer.

Correct Answer: B

Rationale: The correct answer is a 45-year-old woman who is obese and has a menstrual pattern consisting of periods of amenorrhea and infrequent periods. Obesity and prolonged exposure to estrogen unopposed by progesterone due to infrequent ovulation are significant risk factors for endometrial cancer. Choices A, C, and D do not directly correlate with the increased risk of endometrial cancer. Postmenopausal status alone (Choice A), overweight with hypertension (Choice C), and smoking (Choice D) are not the primary risk factors for endometrial cancer.