Case Report: tuberculous pleurisy mimicking mesothelioma in a 37-year-old Chinese woman

Abstract

Background

Tuberculosis is a great mimicker of infectious as well as non-infectious diseases, such as cancer. Tuberculous pleurisy is one of the most common extrapulmonary tuberculosis manifestations, and it is difficult to diagnose.

Case presentation

We describe a case of tuberculous pleurisy presenting with diffuse bilateral pleural thickening. This 37 year old woman had 1-year history of intermittent shortness of breath for which CT thorax was obtained at community hospital that showed bilateral pleural thickening. Increased fluorodeoxyglucose uptake along nodular bilateral pleural thickenings and in the hilar lymph nodes mimicked mesothelioma. Subsequent acid-fast staining of the pleural biopsy specimen was positive. The patient received antituberculosis therapy for 6 months, with clearly improved pleural lesions on chest computed tomography.

Conclusion

In relatively young individuals presenting with diffuse pleural thickening, even when there are minimal intermittent subjective symptoms, the possibility of tuberculosis should not be ignored.

Introduction

Tuberculosis (TB) remains the leading cause of death from infectious diseases worldwide and is responsible for an estimated 1 674 000 deaths annually [1]. Tuberculous pleurisy is one of the most common extrapulmonary manifestations of TB, and it is difficult to diagnose because the positive culture rate for TB in pleural fluid is usually low [2–4]. However, diagnosing tuberculous pleurisy is important in China because the country currently has a relatively high TB prevalence. Some infections, particularly TB, are known to mimic cancer. Previous studies showed that false-positive fluorodeoxyglucose (FDG) uptake has been reported in patients with TB [5, 6]. Here, we report a case of tuberculous pleurisy mimicking mesothelioma in a 37-year-old Chinese woman with intense pleural FDG uptake, which, to our knowledge, has been reported rarely in mainland China.

Case description

On 30 November 2021, a 37-year-old Chinese woman was referred to our hospital because abnormal chest computed tomography (CT) findings were identified in a routine health checkup 10 days earlier. Chest CT in a community hospital showed diffuse thickening of bilateral pleura. The patient had a 1-year history of intermittent shortness of breath when her physical activity level increases. She also had a 9-year history of diabetes mellitus, no history of pulmonary or autoimmune disease or occupational exposure to asbestos, silica, or other fibrogenic substances, no history of BCG vaccine, and no recent history of travel or contact with pigeon excrement. Her father had been treated for smear-positive pulmonary TB in June, 2021.

Vital signs of the patients were in the normal ranges with a blood pressure of 104/75 mmHg, a heart rate of 96 bpm, a body temperature of 36.4 °C, a respiratory rate of 20 bpm. Examination of the patient revealed that breath sounds were decreased in both lungs. In addition, there was no other abnormal finding. Notable laboratory examination results after admission were as follows: C-reactive protein: 14.88 mg/L, D-Dimer: 0.66 mg/L, HbA1C:7.9% and erythrocyte sedimentation rate: 23.00 mm/h. A full blood cell count, the results of liver and renal function tests, and other data, such as the HIV antibody, the antinuclear antibody spectrum, ANCA, and rheumatoid factor tests, were within normal limits. Bacterial, fungal, and acid-fast bacilli cultures in the sputum were also negative. Pulmonary function tests showed severe restrictive ventilatory disorder, decreased expiratory flow rate, and mildly decreased lung diffusion capacity.

Chest CT in our hospital showed ring-like enhancement in bilateral chest walls and diffuse bilateral pleural thickening with mild bilateral pleural effusion (Fig. 1A). Further investigation with positron emission tomography (PET)/CT demonstrated increased ¹⁸F-FDG avidity along nodular bilateral pleural thickening and in the hilar lymph nodes (Fig. 1B). Chest CT of the patient described in our case showed no concominant parechymal disease (Fig. 1C).On the basis of the characteristic imaging findings, mesothelioma or pseudomesotheliomatous carcinoma were suspected. However, with the patient’s history of diabetes and a contact history for TB, TB could not be excluded. Subsequently, the results of a tuberculin skin test and interferon-γ release assay were positive. The patient also underwent CT-guided percutaneous left pleural biopsy, which showed proliferative fibrocollagenous tissue accompanied by mild cellular necrosis. Acid-fast staining of the biopsy specimen was positive (Fig. 2A). The patient’s pleural biopsy puncture needle rinsing solution were tested using PCR and TB culture, and the test results were negative. Additionally, we further performed X-pert examination using the acid-resistant positive tissue slices. The result showed that extremely low Mtb was detected, and no rifampicin resistance was detected. On the basis of these findings, the patient was diagnosed with bilateral tuberculous pleurisy. Thus, antituberculosis therapy was initiated with a four-drug regimen comprising isoniazid, rifampicin, pyrazinamide, and levofloxacin, which resulted in clinical improvement. Fundus examination in the patient indicated diabetic retinopathy, so the ethambutol was excluded. On 8 May 2022, chest CT at the outpatient clinic revealed that the pleural lesions were improved compared with the previous images (Figs. 2B and 3).

Fig. 1.

(A) Chest computed tomography showing diffuse bilateral pleural thickening. Yellow arrows: thickened bilateral pleura with the thickest point being approximately 20 mm; A blue arrow: enlargement of hilar lymph node with calcification; Red arrows: thickened pleura with irregular nodules. (B) Positron emission tomography/computed tomography showing increased fluorodeoxyglucose avidity along nodular bilateral pleural thickening and in the hilar lymph nodes. Green arrows: diffuse increase in radioactive uptake. (C) Chest CT of the patient described in our case showed no concominant parechymal disease

Fig. 2.

(A) Histopathological findings of the left pleural biopsy showed proliferative fibrocollagenous tissue accompanied by mild cellular necrosis (left). Positive acid-fast staining of the biopsy specimen was positive (right). (B) Follow-up chest computed tomography showing fewer pleural lesions compared with the images in Fig. 1A

Fig. 3.

Timeline of the disease development, signs and symptoms, diagnostic workup and findings, medical treatment, and 6-month follow-up

Discussion

Tuberculous pleurisy usually presents as an acute illness. However, depending on factors such as lung affected area and lesion distribution, the typical symptoms of TB may be absent in patients with tuberculous pleurisy. In this case study, we encountered a relatively young patient with diffuse pleural thickening while there are minimal subjective symptoms. Because of the patient’s history of diabetes and a contact history for TB, TB was suspected. Finally, Acid-fast staining of the biopsy specimen was positive and the patient was diagnosed with tuberculous pleurisy. As reported in a previous study [7], bilateral pleural involvement was rare in TB.

FDG PET/CT is an important imaging tool for the diagnosis of malignant pleural mesothelioma [8]. However, FDG is not a specific modality for malignant disease. FDG intensity is an indicator of the glycolytic activity of lesions, which is observed not only in malignant diseases but also in infectious disease [9]. In TB, increased FDG uptake on lesion area is associated with increased glucose utilization in activated macrophages and lymphocytes [10]. Therefore, for the evaluation of pleural pathologies in TB-endemic countries, the possibility of false-positive results should be considered with FDG PET/CT. Interestingly, the pleural thickening with no subjective symptoms in our case showed intense FDG uptake and was proven to be caused by tuberculous pleurisy.

Significantly, Kumar P, et al. reported a case of TB coexisting with malignant peritoneal mesothelioma [11]. In a case of TB not responding to treatment and having an uncommon presentation, possibility of underlying different pathology should be explored. In this case report, histopathological findings of the pleural biopsy showed proliferative fibrocollagenous tissue accompanied by mild cellular necrosis. Clear proliferation of mesothelial cells and tumor lesions have not been observed in the histopathological findings. Therefore, immunohistochemical studies for WT-1, pancytokeratin, calretinin, CK5/6, TTF-1, and p40 have not been performed.

The definitive diagnosis of tuberculous pleurisy depends on the demonstration of tubercle bacilli in the sputum, pleural fluid, or pleural biopsy specimens. Histological analysis and mycobacterial culture of biopsied pleural tissue have traditionally been the gold standard diagnostic methods [12]. In the current case, acid-fast staining of the biopsy specimen was positive, which is important for the diagnosis of tuberculous pleurisy.

Conclusion

TB should be considered in relatively young individuals presenting with diffuse pleural thickening even when there are minimal intermittent subjective symptoms.

Author contributions

Xiuping Liu and Chengqing Yang: study conceptualization, organization, analysis outcome verification, and critical editing and review of the manuscript. Xiuping Liu, Chunlin Mei and Shufang Che: data collection. Xiuping Liu: manuscript preparation. Tanze Cao: manuscript revision. All authors contributed to the article and approved the submitted version.

Funding

This work was supported by a fund from the Hubei Provincial Health Research Foundation (Grant No: WJ2019H320).

Data availability

No datasets were generated or analysed during the current study.

Declarations

Ethics approval and consent to participate

The study was conducted under ethical principles (Declaration of Helsinki). Written consent was obtained from her authorized representatives.

Consent for publication

Written informed consent was obtained from the patient for publication of this report and any accompanying images.

Competing interests

The authors declare no competing interests.