A 45-year-old woman presents with fatigue, weight gain, and cold intolerance. Her thyroid function tests reveal low T3 and T4 levels and elevated TSH levels. Which of the following is the most likely diagnosis?

Correct Answer: B

Rationale: The scenario describes a 45-year-old woman with fatigue, weight gain, cold intolerance, low T3 and T4 levels, and elevated TSH levels, which are indicative of hypothyroidism. In hypothyroidism, there is decreased production of thyroid hormones (T3 and T4) leading to elevated TSH levels as the pituitary gland tries to stimulate the thyroid gland to produce more hormones. Therefore, the correct answer is hypothyroidism (Choice B). Choice A, Hyperthyroidism, is incorrect as the patient's symptoms and thyroid function tests point towards decreased thyroid hormone levels, which is characteristic of hypothyroidism, not hyperthyroidism. Choice C, Euthyroid sick syndrome, is incorrect because this condition typically presents with normal to low T3 and T4 levels in the setting of non-thyroid illness, unlike the elevated TSH levels observed in this case. Choice D, Subclinical hyperthyroidism, is also incorrect as the patient has low T3 and T4 levels, which is not consistent with hyperthyroidism, whether clinical or subclinical.

Correct Answer: C

Rationale: In a 60-year-old man presenting with painless hematuria, the next step in the evaluation should be cystoscopy. Cystoscopy is recommended to assess the cause of hematuria, particularly to rule out bladder cancer, which is more common in older individuals. Urinalysis (Choice A) can provide initial information but may not definitively diagnose the underlying cause. Renal ultrasound (Choice B) and intravenous pyelogram (Choice D) are imaging studies that may be considered later in the evaluation process but are not the initial step for painless hematuria.

Correct Answer: A

Rationale: The correct answer is A: Tuberculosis. Cavitary lesions in the upper lobes are classic findings seen in tuberculosis. This infectious disease commonly presents with symptoms such as chronic cough, night sweats, and weight loss. Pneumonia (Choice B) typically does not present with cavitary lesions on chest X-ray. Lung cancer (Choice C) may present with similar symptoms but is less likely to cause cavitary lesions in the upper lobes. Sarcoidosis (Choice D) usually presents with bilateral hilar lymphadenopathy and non-caseating granulomas, different from the cavitary lesions described in the case.

Correct Answer: B

Rationale: Pulmonary edema is a common finding in congestive heart failure. In congestive heart failure, the heart is unable to pump effectively, leading to fluid buildup in the lungs, causing pulmonary edema. This results in symptoms like shortness of breath, coughing, and wheezing. Choices A, C, and D are not typically associated with congestive heart failure. Jugular venous pressure is often elevated, not decreased in heart failure. Hyperactive bowel sounds and weight loss are not specific findings for congestive heart failure.

Correct Answer: B

Rationale: The correct answer is B: Systemic lupus erythematosus. Joint pain, a malar rash, and photosensitivity are classic symptoms of systemic lupus erythematosus. Choice A, Rheumatoid arthritis, is incorrect as it typically presents with symmetric joint involvement and morning stiffness. Psoriatic arthritis (Choice C) is characterized by joint pain associated with psoriasis, which is not described in the case. Dermatomyositis (Choice D) presents with muscle weakness, skin rash, and elevated muscle enzymes, different from the symptoms presented in the case.