Pleural effusion resulting from bronchial tuberculosis: A case report.

RATIONALE: The clinical manifestations in patients with bronchial tuberculosis (BTB) are nonspecific and may pose a great diagnostic challenge. PATIENT CONCERNS: Here we describe the case of a 57-year-old man presented with right chest pain, chest tightness, and discomfort for 2 days. DIAGNOSIS: Bronchoscopic biopsy was performed which revealed subepithelial and epithelioid cell granuloma of Langerhans cell structure. The definitive diagnosis was BTB with pleural effusion.
INTERVENTIONS: Treatment with a quadruple combinational antituberculous therapy was initiated. OUTCOMES: Two months later, the patient's chest distress and discomfort significantly decreased. Repeat chest radiograph revealed that the pleural fluid had been absorbed. The patient recovered after 15 months of antituberculosis treatment. LESSONS: The patient exemplifies the difficulty of diagnosing BTB, particularly the low reliability of imaging modalities. The diagnosis of BTB currently relies on bronchoscopy as well as bacteriological or pathological evidence. This report will help to lower the incidences of misdiagnosis of this disease.

Introduction

Tuberculosis (TB) is a disease of poverty, affecting the most vulnerable groups of the world's population: more than half of TB-related deaths occur in Asia, while the greatest TB burden as percentage of population is in Africa.[ Bronchial tuberculosis (BTB) is a particular clinical type of this disease that falls within the category of lower respiratory tract TB. The clinical manifestations in patients with BTB are nonspecific, and imaging examinations are sometimes of limited diagnostic use.[ Pleural effusion is not commonly the primary clinical manifestation in patients with BTB; moreover, pleural fluid tests lack specificity and can readily lead to misdiagnosis or missed diagnosis.[ The patient we report here sought medical attention due to chest pain, chest tightness, and discomfort, and was found to have pleural effusion detected via a chest computed tomography (CT) scan. He was initially misdiagnosed with inflammatory pleural effusion, which resulted in prolonging his condition. Finally, a definite diagnosis of BTB was made following tracheoscopy. After aggressive anti-TB treatment, the pleural effusion was absorbed and the symptoms improved.

Case report

The 57-year-old man, a farmer living in a rural area of Chizhou, Anhui Province, China, was admitted to our hospital after experiencing right chest pain, chest tightness, and discomfort for 2 days. Auscultation revealed reduced breath sounds in the lower lobe of the right lung. A routine blood routine revealed the following: white blood cell count, 5.57 × 109/L; neutrophils, 75.91%, lymphocytes, 12.62%; red blood cell count, 4.47 × 1012/L; hemoglobin, 123 g/L; platelets, 227 × 109/L; erythrocyte sedimentation rate, 46 mm/h; and C-reactive protein (CRP), 54.64 mg/L. The plasma D-dimer level was 2168 ng/mL; tumor markers and autoimmune antibodies were normal. The patient was negative for Mycoplasma pneumoniae; the T-SPOT T-cell test for TB infection as well as purified protein derivative tests for TB were also negative, as were repeated sputum analyses for acid-fast bacilli.

Chest CT revealed atelectasis of the lower lobes of the right lung, right-sided pleural effusion, and enlarged lymph nodes in the mediastinum (Fig. 1). Upon the patient's request, a pleural biopsy was not performed. However, a paracentesis was performed on the right thoracic cavity and a routine pleural fluid test was conducted. Rivalta test was positive. The pleural fluid pH was 7.32 (reference: 6.8–7.6), while the lactate dehydrogenase level was 285 U/L (reference: 0–200 U/L). The adenosine deaminase (ADA) level was 25 U/L (reference: 0–40 U/L), and carcinoembryonic antigen level was 1.03 ng/mL (reference: 0–6.5 ng/mL). Pleural fluid TB antibodies were negative, and a retest of the pleural fluid showed an ADA level of 23 U/L. Repeated pleural fluid cytological examinations showed a distribution of lymphocytes and neutrophils, and the pleural fluid culture was negative. The patient was thus diagnosed with inflammatory pleural effusion.

Figure 1

Chest computed tomography. Atelectasis of the lower lobes of the right lung is observed, along with right-sided pleural effusion and enlarged lymph nodes in the mediastinum.

After admission, 0.2% levofloxacin (300 mL intravenously, qd) was administered as an antiinflammatory therapy for 2 weeks, after which a repeat test showed normal CRP levels and a significantly decreased pleural fluid volume. The patient was then discharged. During a follow-up visit 1 month later, the patient reported a recurrence of chest discomfort. A repeat chest CT revealed encapsulated effusion and mild pleural thickening in the right thoracic cavity. Further bronchoscopy revealed granulomatous protruding neoplasms and partial blockage of the lumen (Fig. 2). Pathological examination of the biopsy sample from the upper lobe of the right lung revealed the bronchial surface epithelial metaplasia, subepithelial and epithelioid cell granuloma of Langerhans cell structure, which was considered to be TB (Fig. 3). The diagnosis was amended to right-sided BTB with pleural effusion. A quadruple combinational antituberculous therapy consisting of rifampicin 0.45 g qd, iproniazid 0.3 g qd, ethambutol 0.75 g qd, and pyrazinamide 0.5 g tid was administered orally. Two months later, the patient's chest distress and discomfort significantly improved. Repeat chest radiograph revealed that the pleural fluid had been absorbed (Fig. 4). The patient recovered after 15 months of anti-TB treatment.

Figure 2

Bronchoscopy results. Granulomatous protruding neoplasm(s) and partial blockage of the lumen in the right main bronchus are observed.

Figure 3

Pathological examination of the upper lobe of the right lung. The bronchial surface epithelial metaplasia, subepithelial and epithelioid cell granuloma of Langerhans cell structure, which was considered to be tuberculosis (hematoxylin and eosin staining; magnification ×400).

Figure 4

Chest radiograph. The pleural fluid had been absorbed. Informed written consent was obtained from the patient for publication of this case report and accompanying images.

Discussion

BTB refers to TB occurring in the mucosa, submucosa, smooth muscle, cartilage, and epithelium of the bronchus.[ The detection rate of BTB has significantly increased in the recent years.[ Data show that 5% to 10% of patients have no tuberculous lesions in their lungs; they only experience invasion of their trachea and bronchi. BTB mostly occurs in young and middle-aged women, with a male-to-female ratio of 1:2–1:3.[ As bronchoscopy is an invasive procedure and not routine, it is difficult to perform an epidemiological investigation of BTB; however, the pulmonary function impairment caused by BTB has become a problem that cannot be overlooked.

As the clinical manifestations in patients with BTB often lack specificity, and since imaging examinations have inherent limitations, the diagnosis of BTB currently relies on bronchoscopy as well as bacteriological or pathological evidence.[ The screening of patients who seek medical attention after they experience relevant symptoms is currently the main approach for detecting BTB. Typical clinical manifestations include an irritative cough, expectoration, hemoptysis, dyspnea, and other respiratory symptoms.[ Some patients may experience systemic symptoms such as fever, night sweats, weight loss, and irregular menstruation. Patients may also experience allergic reactions such as reactive arthritis and conjunctivitis. A small portion of patients will have slight or no discomfort, and BTB will be found during auxiliary examinations for pulmonary TB or other diseases. Due to the lack of specificity or even the absence of clinical manifestations in patients with BTB, definite diagnoses cannot be made based on signs and symptoms alone.[ Imaging studies not only assess whether a bronchoscopy is necessary for clinical diagnosis, but can also provide an important reference for the establishment of an intratracheal intervention plan after diagnosis. However, this is associated with high rates of misdiagnosis and missed diagnosis.[ Positive results of sputum smear and mycobacterium tuberculosis (MTB) tests are the gold standards for the diagnosis of TB. For patients without tuberculous lesions in their lungs, a positive sputum bacteria test is highly suggestive of BTB, but further examinations are still required to arrive at definite diagnoses. A negative sputum bacteria test cannot exclude the presence of BTB, especially in patients with typical clinical manifestations of TB. The low positive rate of sputum acid-fast bacilli in patients with BTB,[ together with the long incubation periods of MTB and over-reliance on the sputum bacteria test, often delay the diagnosis of BTB or lead to misdiagnosis or missed diagnosis. Therefore, bronchoscopy should be performed as early as possible.

Bronchoscopy is an indispensable approach for the definitive diagnosis of BTB. Direct observation is accomplished through a bronchoscope, samples such as relevant smears and lavage fluids are obtained for MTB-related examinations, and biopsy samples are obtained for pathological and other examinations in order to confirm the diagnosis of BTB.[ By using bronchoscopy, lesions in the bronchi can be observed directly; their types, locations, scopes, severities, and etiologies can thus be determined, and the occurrences and degrees of airway stenosis, occlusion, and softening can be assessed. Bronchial lesion tissue samples can be obtained through bronchoscopy to test for histopathological manifestations such as exudation, hyperplasia, and degeneration. Detection of epithelioid cells, Langhans giant cells, and caseous necrosis can assist in the diagnosis of BTB, while detection of acid-fast bacilli supports this diagnosis as well.[

The incidence of pleural effusion in BTB is low and rarely reported clinically, so we cannot reach any conclusion regarding the likelihood that BTB patients might have pleural effusion.[ In the present case, the patient had an exudate. The mechanism of its occurrence remains unclear, and it is possible that the disease itself may lead to pleural disruption, thus causing exudative pleurisy; however, there is a lack of histological evidence to support this concept. Pleural biopsies can easily miss the location of the lesion, since they can only collect a relatively small amount of the sample, and they may be prone to false negative results.[ The mechanism of pleural effusion in BTB patients still need to be further investigated.[

In conclusion, our patient exemplifies the fact that the clinical manifestations of BTB lack specificity, and imaging examinations are limited in their diagnostic utility. We presented a patient with BTB who exhibited pleural effusion that was diagnosed by tracheoscopy, and was successfully treated with anti-TB agents. This case ought to improve clinicians’ understanding of this disease and therefore reduce the likelihood of misdiagnosis.

Author contributions

Investigation: Xuchun Liu, Litao Xu.

Resources: Xuchun Liu, Litao Xu.

Validation: Guohua Jiang, Shubin Huang.

Writing—original draft: Xuchun Liu.

Writing—review & editing: Xuchun Liu, Guohua Jiang, Shubin Huang.