A 35-year-old woman comes to the office due to anorexia and unintentional weight loss of 10 kg (22 lb) over the past 3 months. She has also had occasional cough, subjective fevers, and night sweats. The patient has no prior medical problems and takes no medications. She was previously homeless and used injection drugs but has not done so for 4 years and now has stable housing and employment. The patient does not use tobacco or alcohol. Temperature is 37 C (98.6 F), pulse is 90/min, blood pressure is 120/70 mm Hg, and respiratory rate is 16/min. Physical examination reveals inspiratory crackles over the right upper lung field. Chest x-ray reveals an infiltrate with small cavitation in the apical-posterior segment of the right upper lobe. Rapid HIV testing is negative.
Which of the following is the most appropriate for establishing the diagnosis in this patient?

Question

A 35-year-old woman comes to the office due to anorexia and unintentional weight loss of 10 kg (22 lb) over the past 3 months.  She has also had occasional cough, subjective fevers, and night sweats.  The patient has no prior medical problems and takes no medications.  She was previously homeless and used injection drugs but has not done so for 4 years and now has stable housing and employment.  The patient does not use tobacco or alcohol.  Temperature is 37 C (98.6 F), pulse is 90/min, blood pressure is 120/70 mm Hg, and respiratory rate is 16/min.  Physical examination reveals inspiratory crackles over the right upper lung field.  Chest x-ray reveals an infiltrate with small cavitation in the apical-posterior segment of the right upper lobe.  Rapid HIV testing is negative. 
Which of the following is the most appropriate for establishing the diagnosis in this patient?

Quizplus · Accepted Answer

Explanation: 11ec2b69_c17d_5680_8f63_39f9466132f9_MD0005_00 This patient's clinical presentation is consistent with active pulmonary tuberculosis (TB), which is typically due to the reactivation of latent disease. Suspicion should be raised when individuals with epidemiologic risk factors for exposure (eg, substance abuse, homelessness, birth in a TB-endemic region) develop characteristic clinical manifestations (eg, fever, cough >2 weeks, weight loss). Diagnostic evaluation begins with chest x-ray to determine if there are signs of active disease such as upper lobe cavitation (70%-80%), hilar lymphadenopathy, or pleural effusion. Patients with suspicious x-ray findings are definitively diagnosed when Mycobacterium tuberculosis is isolated in body fluid or tissue (lung, pleura). Sputum sampling provides the least invasive and costly route for microbial confirmation. Three single sputum samples (spontaneous or induced) are submitted in 8- to 24-hour intervals with at least 1 early-morning sample. Sputum should be sent for acid-fast bacillus smear, mycobacterial culture, and nucleic acid amplification testing. Although patients with suspected pulmonary TB should also undergo tuberculin skin testing or interferon-gamma release assay, these tests cannot distinguish between active and latent disease and are ordered primarily to support the diagnosis (positive test results suggest exposure) (Choices B and E). (Choice A) Bronchoscopy with bronchoalveolar lavage is more invasive and expensive than sputum sampling and is generally reserved for patients who are unable to produce adequate expectorated or induced sputum, have negative sputum studies with a high suspicion for active TB, or have a possible alternate diagnosis that requires bronchoscopy for evaluation. (Choice D) Transthoracic needle aspiration is invasive and associated with a greater risk of complications than either sputum testing or bronchoscopy with bronchoalveolar lavage. As a result, it is typically reserved for patients who remain undiagnosed after these tests. Educational objective: Patients with suspected pulmonary tuberculosis who have abnormal chest imaging should undergo sputum acid-fast bacillus smear, mycobacterial culture, and nucleic acid amplification testing for microbial confirmation. Tuberculin skin testing or interferon-gamma release assay are also typically performed, but these tests cannot be used to distinguish active from latent infection. References: Current concepts in the management of tuberculosis. (http://www.ncbi.nlm.nih.gov/pubmed/21454737)

A 35-Year-Old Woman Comes to the Office Due to Anorexia