On visualization of the penis he is circumcised and there are no lesions and no discharge from the meatus. His scrotal skin is tense and red. Palpation of the left testicle causes severe pain and the patient begins to cry. His prostate examination is unremarkable. His cremasteric reflex is absent on the left but is normal on the right. By catheter you get a urine sample and the analysis is unremarkable. You send the boy with his mother to the emergency room for further workup. What is the most likely diagnosis for this young man's symptoms?

Correct Answer: C

Rationale: The presentation of severe testicular pain with a red, tense scrotum, and absent cremasteric reflex on one side is highly concerning for testicular torsion. Testicular torsion is a urologic emergency that occurs when the spermatic cord twists, leading to compromised blood flow to the testicle. The affected testicle can become ischemic and necrotic within hours, necessitating prompt diagnosis and intervention to avoid permanent damage or loss of the testicle.

Correct Answer: D

Rationale: The group of lymph nodes that lie just behind the sternocleidomastoid muscles bilaterally are known as the posterior cervical lymph nodes. These lymph nodes are part of the superficial cervical lymph node chain, which is involved in draining lymph from the head and neck region. In the case described, the presence of sore throat, fever, and enlarged tonsils with exudates suggests a likely upper respiratory tract infection or tonsillitis, leading to the enlargement of the nearby lymph nodes. The posterior cervical lymph nodes are commonly examined in cases of upper respiratory infections and tonsillitis due to their proximity to the area of infection and inflammation.

Correct Answer: C

Rationale: Diminished radial pulses may be seen in patients with arterial emboli. Arterial emboli are blood clots that travel through the bloodstream and get lodged in a blood vessel, blocking blood flow to a certain area. When an embolus affects the arteries supplying the arm, it can lead to diminished pulses in the affected arm, such as the radial pulse in the wrist. This diminished pulse is due to decreased blood flow to the area beyond the blockage caused by the embolus. This distinguishes arterial emboli from the other options listed, as aortic insufficiency, hyperthyroidism, and early "warm" septic shock typically do not cause isolated diminished radial pulses.

Correct Answer: D

Rationale: The given symptoms of distant air sounds, late inspiratory crackles in both lower lobes, distant S1 and S2 heart sounds, and an S3 heart sound heard over the apex are all characteristic findings of left-sided heart failure. Distant air sounds and late inspiratory crackles indicate pulmonary congestion due to fluid accumulation in the lungs as a result of left-sided heart failure. The distant heart sounds and presence of an S3 are signs of left ventricular dysfunction. In contrast, pneumonia would typically present with more localized abnormal breath sounds and other symptoms such as fever and productive cough. Chronic obstructive pulmonary disease (COPD) would manifest with prolonged expiratory phase and wheezing, not late inspiratory crackles. Pleural pain is typically associated with sharp chest pain exacerbated by breathing movements, and it does not explain the constellation of symptoms described in this case. Therefore, the most likely diagnosis based on the provided symptoms

Correct Answer: B

Rationale: The dullness in the last intercostal space in the anterior axillary line on the left side with a deep breath is suggestive of splenomegaly. However, this finding alone is not definitive for an enlarged spleen. The size of the spleen can vary, and further examination is required to confirm if the spleen is indeed enlarged. Therefore, Option B is the most appropriate choice as it indicates that the spleen is possibly enlarged, and close attention should be paid to further examination to confirm its status. Further workup, such as imaging studies or blood tests, may be necessary to evaluate the size and function of the spleen in this case.