A 24-year-old man comes to the office due to nonproductive cough, subjective fevers, right-sided pleuritic chest pain, and increasing dyspnea for the past 4 weeks. He was empirically treated for pneumonia with levofloxacin at an urgent care center 2 weeks ago but has had no improvement. The patient is an exchange student from the Philippines. Temperature is 37.3 C (99.1 F), blood pressure is 118/66 mm Hg, pulse is 90/min, and respirations are 20/min. Physical examination is remarkable for decreased right-sided breath sounds. Chest x-ray shows a large, right-sided pleural effusion. Pleural fluid is drained, and a subsequent chest CT scan reveals right upper lobe infiltrate and calcified hilar adenopathy. This patient's pleural fluid analysis is most likely to demonstrate which of the following findings?

Question

A 24-year-old man comes to the office due to nonproductive cough, subjective fevers, right-sided pleuritic chest pain, and increasing dyspnea for the past 4 weeks.  He was empirically treated for pneumonia with levofloxacin at an urgent care center 2 weeks ago but has had no improvement.  The patient is an exchange student from the Philippines.  Temperature is 37.3 C (99.1 F), blood pressure is 118/66 mm Hg, pulse is 90/min, and respirations are 20/min.  Physical examination is remarkable for decreased right-sided breath sounds.  Chest x-ray shows a large, right-sided pleural effusion.  Pleural fluid is drained, and a subsequent chest CT scan reveals right upper lobe infiltrate and calcified hilar adenopathy.  This patient's pleural fluid analysis is most likely to demonstrate which of the following findings?

Quizplus · Accepted Answer

11ec160b_3b42_fd25_9249_ffe8ccd71d6e_MD0001_00 This patient's clinical findings are consistent with reactivation tuberculosis, given his nonresponse to routine pneumonia treatment, prior residence in an endemic region (ie, Southeast Asia), and CT scan showing calcified hilar adenopathy (representing granulomatous lymph node involvement). Reactivation tuberculosis typically affects the upper lobes of the lungs and is often associated with pleural effusion. Pulmonary infection causes pleural effusion primarily via an inflammatory increase in vascular and pleural membrane permeability, leading to relatively high pleural fluid protein and lactate dehydrogenase (LDH) concentration (Choice D). Such effusions are exudative by Light criteria, with pleural fluid/serum protein ratio >0.5, pleural fluid/serum LDH ratio >0.6, and/or pleural fluid LDH >⅔ the upper limit of normal serum LDH. Normal serum total protein ranges from 6.0 g/dL to 7.8 g/dL; therefore, pleural fluid protein >4 g/dL (ratio >0.5) is most likely in this patient. (Choice A) Pleural fluid cytology showing atypical cells can be seen with a malignant pleural effusion, but is not expected with tuberculous effusion. Malignant effusions are also typically exudative by Light criteria. (Choice B) An elevated pleural fluid triglyceride level is diagnostic of a chylothorax, which results from disruption (eg, trauma, malignant invasion) of the thoracic duct leading to leakage of chylomicron-rich lymphatic fluid into the pleural space. (Choice E) Tuberculosis pleural effusions are typically lymphocyte predominant. Neutrophil predominance is expected with a typical parapneumonic effusion (eg, due to community-acquired bacterial pneumonia). Educational objective: Pulmonary infection (eg, community-acquired pneumonia, tuberculosis) causes pleural effusion primarily via an inflammatory increase in vascular and pleural membrane permeability. Such effusions are exudative by Light criteria, typically with relatively high pleural fluid protein and lactate dehydrogenase concentrations. Tuberculosis pleural effusions typically demonstrate a lymphocyte-predominant leukocyte pattern. __________ References: Diagnostic approach to pleural effusion in adults. (http://www.ncbi.nlm.nih.gov/pubmed/16623208)

A 24-Year-Old Man Comes to the Office Due to Nonproductive