A 40-year-old man comes to the emergency department with 2 weeks of fever, malaise, weakness, and an unintentional 2.3-kg (5-lb) weight loss. During the last 4 days, he developed left-sided chest and upper abdominal pain. He has asymptomatic mitral valve prolapse. His wife was treated for an upper respiratory infection 3 weeks ago. The patient works for a large corporation and frequently travels to Mexico. He has a 20-pack-year smoking history. He does not use alcohol. His temperature is 39.4 C (103 F), blood pressure is 120/70 mm Hg, pulse is 96/min, and respirations are 16/min. Lung examination shows decreased breath sounds in the left lower lung field with dullness to percussion. Cardiac examination shows a 2/6 systolic murmur at the apex. Laboratory results are as follows: Imaging studies reveal left-sided pleural effusion and splenomegaly with a splenic fluid collection. Which of the following is the most likely underlying diagnosis in this patient?

Question

A 40-year-old man comes to the emergency department with 2 weeks of fever, malaise, weakness, and an unintentional 2.3-kg (5-lb) weight loss.  During the last 4 days, he developed left-sided chest and upper abdominal pain.  He has asymptomatic mitral valve prolapse.  His wife was treated for an upper respiratory infection 3 weeks ago.  The patient works for a large corporation and frequently travels to Mexico.  He has a 20-pack-year smoking history.  He does not use alcohol.  His temperature is 39.4 C (103 F), blood pressure is 120/70 mm Hg, pulse is 96/min, and respirations are 16/min.  Lung examination shows decreased breath sounds in the left lower lung field with dullness to percussion.  Cardiac examination shows a 2/6 systolic murmur at the apex.  Laboratory results are as follows:  Imaging studies reveal left-sided pleural effusion and splenomegaly with a splenic fluid collection.  Which of the following is the most likely underlying diagnosis in this patient?

Quizplus · Accepted Answer

11ec25c8_d886_c301_bc81_87b02f25daf5_MD0003_00 This patient's presentation is consistent with a likely splenic abscess, which classically causes the triad of fever, leukocytosis, and left upper-quadrant abdominal pain (due to a splenic fluid collection). Patients can also develop left-sided pleuritic chest pain, left pleural effusion, and splenomegaly. Risk factors for splenic abscess include infection (eg, infective endocarditis) with hematogenous spread, immunosuppression, IV drug use, trauma, and hemoglobinopathies. Diagnosis is usually confirmed by CT scan of the abdomen. Splenic abscess is typically due to infective endocarditis (or seeding from another site of infection). Likely mechanisms include hematogenous seeding or septic emboli to the spleen. Common causative organisms are Staphylococcus, Streptococcus, and Salmonella. Antibiotics alone for treating splenic abscess have a high mortality (up to 50% in some studies). As a result, splenectomy is recommended for all patients. Percutaneous drainage may be an option in poor surgical candidates. Patients with preexisting structural cardiac conditions are at increased risk of endocarditis. There should be strong suspicion for endocarditis in this patient who has mitral valve prolapse (associated with a fivefold increased risk of endocarditis at least), fever with systemic manifestations (eg, malaise, weight loss), and splenic abscess (likely due to septic emboli); therefore, to complete the evaluation for Duke criteria, blood cultures should be obtained and echocardiography should be performed, particularly if blood culture results are positive. (Choice A) Malaria can cause fever, chills, and fatigue; anemia, thrombocytopenia, and jaundice are also common. Splenic abscess is not seen with malaria although splenomegaly can be present. (Choice B) Hodgkin lymphoma can present with fever, chills, and weight loss. Lymphoma can also be associated with splenomegaly but typically does not cause splenic abscess or infarction. (Choice C) Infectious mononucleosis is due to the Epstein-Barr virus. Patients usually develop lymphadenopathy, fever, and possible hepatosplenomegaly. However, infectious mononucleosis is usually not associated with left pleural effusion or splenic abscess. It is also uncommon in this age group. (Choice E) Lung adenocarcinoma can present with fever, weight loss, dyspnea, and pleural effusion, as seen in this patient. However, lung cancer usually metastasizes to the liver, bone, brain, and adrenal glands. Splenic abscess is not seen in the absence of an additional infectious process. (Choice F) Tuberculosis can present with fever and weight loss. Gastrointestinal tuberculosis most commonly involves the liver, intestine, and peritoneum. However, splenic involvement is less common, and symptoms are more chronic in nature. Educational objective: Splenic abscess usually presents with the classic triad of fever, leukocytosis, and left upper-quadrant abdominal pain. Patients can also develop left-sided pleuritic chest pain, left pleural effusion, and splenomegaly. Risk factors for splenic abscess include hematogenous spread, immunosuppression, intravenous drug use, trauma, and hemoglobinopathies. Infective endocarditis is most commonly associated with splenic abscess. References: Splenic abscesses. (http://www.ncbi.nlm.nih.gov/pubmed/22206933) Splenic infarction and abscess complicating infective endocarditis. (http://www.ncbi.nlm.nih.gov/pubmed/19857437)

A 40-Year-Old Man Comes to the Emergency Department with 2