Chris is a 20-year-old college student who has had abdominal pain for 3 days. It started at his umbilicus and was associated with nausea and vomiting. He was unable to find a comfortable position. Yesterday, the pain became more severe and constant. Now, he hesitates to walk, because any motion makes the pain much worse. It is localized just medial and inferior to his iliac crest on the right. Which of the following is most likely?

Correct Answer: D

Rationale: The presentation is highly suggestive of appendicitis, especially given the migration of pain from the periumbilical region to the right lower quadrant (just medial and inferior to the iliac crest). The worsening of pain with motion, along with associated symptoms such as nausea, vomiting, anorexia, and fever, are typical features of appendicitis. The classic presentation of appendicitis is pain starting around the umbilicus (due to visceral innervation) and then shifting to the right lower quadrant (due to irritation of the parietal peritoneum). Surgical intervention is usually required promptly to prevent complications like perforation, which can lead to peritonitis and sepsis.

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: 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: 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: C

Rationale: Marion's presentation of back pain associated with constipation and urinary retention is concerning for cauda equina syndrome. Cauda equina syndrome is a rare but serious condition caused by the compression of the bundle of nerves at the bottom of the spinal cord, known as the cauda equina. This compression can result in a variety of symptoms, including back pain, sciatica, changes in bowel and bladder function (such as constipation and urinary retention), as well as lower extremity weakness or numbness.

Correct Answer: D

Rationale: A rectal polyp is a growth that originates from the inner lining of the rectum and protrudes into the rectal canal. It may present as a soft, smooth, nontender mass on digital rectal examination. Rectal polyps are usually benign, but some may have the potential to become cancerous if left untreated. Therefore, it is important to evaluate and remove polyps to prevent complications. In this case, the description of a pedunculated mass on the posterior wall of the rectum is most suggestive of a rectal polyp.

Correct Answer: C

Rationale: Constrictive pericarditis is a condition where the pericardium becomes thickened and rigid, impairing diastolic filling of the heart. This leads to an increase in venous pressure, including the jugular venous pressure (JVP). The elevated JVP in constrictive pericarditis is a result of impaired ventricular filling rather than forward failure seen in heart failure. Mitral stenosis can lead to an increased JVP due to elevated left atrial pressure, but constrictive pericarditis is a more common cause of elevated JVP in this scenario. Aortic aneurysm is not typically associated with elevated JVP.

Correct Answer: C

Rationale: The information provided pertains to the patient's educational background, living situation, family status, and work activities. This type of information falls under the personal and social history category, as it provides important context about the patient's lifestyle, living conditions, and social support network. Personal and social history is essential for understanding the patient's overall well-being and can impact their health and healthcare needs.

Correct Answer: B

Rationale: In the given scenario, being a 35-year-old archaeologist with fair skin, a family history of melanoma, and many freckles scattered across her skin are all risk factors for melanoma. Age (choice A) is a relevant risk factor as melanoma incidence increases with age. Actinic lentigines (choice C), also known as sunspots, are precancerous skin lesions that can increase the risk of developing melanoma. Heavy sun exposure (choice D) is a significant risk factor as cumulative sun exposure over time can contribute to the development of melanoma.