Videothoracosopy in diagnosis and surgical treatment of tuberculosis

From 1993 to May 2001, 795 psychiatric patients were treated including 563 with pleural effusion, 98 with multiple or solitary tuberculoma, 69 with tuberculous empyema, 14 with fibrotic-cavitary tuberculosis, 51 with disseminated tuberculosis. Mean age of the patients was 32 years. Survey of pleural cavity with pleural or lung biopsy was performed in 691 patients. In tuberculoma 14 lobectomies were performed, 23 patients underwent atypical lung resection without stapler (including with precise technique). Bilateral on-stage interventions were made in 32 patients. In empyema necrectomy and lung decortication were performed. 14 patients underwent videocavernoscopy with sequestrectomy and cavity drainage. In disseminated tuberculosis lung biopsy without staplers was usually performed. Aerohemostasis was achieved with plasma stream. One patient with empyema and one patient with pleural effusion died (lethality was 0.25%). Rate of postoperative complications was 7.5% in tuberculoma and 1.5% in disseminated tuberculosis. Conversion to thoracotomy was necessary in 3 (3%) patients with tuberculoma and 12 (17%) patients with empyema. Mean hospital stay was 4 days after diagnostic surgery and 7 days after lung resection. In pleural effusion diagnosis was verified in 98% cases, in disseminated tuberculosis--in 100%. Videothoracoscopy is the best diagnostic method for pleural effusion and disseminated forms of lung tuberculosis and operation of choice in tuberculoma and empyema. Videothoracoscopy in tuberculosis is highly effective and associates with low rate of postoperative complications and lethality.     

Value of adenosine deaminase in the diagnosis of tuberculous pleural effusions in young patients in a region of high prevalence of tuberculosis.

BACKGROUND--Pleural biopsy is usually considered important for the diagnosis of pleural effusions, especially for distinguishing between tuberculosis and neoplasia, even though tuberculous pleural fluid contains sensitive biochemical markers. In regions with a high prevalence of tuberculosis, and in patient groups with a low risk of other causes of pleurisy, the positive predictive value of these markers is increased. The criteria for performing a pleural biopsy under these circumstances have been investigated, using adenosine deaminase (ADA) as a pleural fluid marker for tuberculosis. METHODS--One hundred and twenty nine patients with a pleural effusion aged < or = 35 years (mean (SD) 25.2 (4.9) years) were studied. Seventy three were men. Eighty one effusions (62.8%) were tuberculous, 12 (9.3%) parapneumonic, and 10 (7.7%) neoplastic, five were caused by pulmonary thromboembolism, four by systemic lupus erythematosus, seven by empyema, three following surgery, one was the result of asbestosis, and one of nephrotic syndrome. In five cases no definitive diagnosis was reached. ADA levels were determined by the method of Galanti and Giusti. RESULTS--The diagnostic yield of procedures not involving biopsy was 94.5% (122/129). Pleural biopsy provided a diagnosis in a further two cases, but not in the remaining five. All tuberculous cases had pleural fluid levels of ADA of > 47 U/l (mean (SD) 111.1 (36.6) U/l). The only other cases in which ADA exceeded this level were six of the seven patients with empyema. Cytological examination of the pleural fluid diagnosed eight of the 10 neoplastic cases, compared with six diagnosed by pleural biopsy. CONCLUSIONS--In a region with a high prevalence of tuberculosis procedures not involving pleural biopsy have a very high diagnostic yield in patients with a pleural effusion aged < or = 35 years, making biopsy necessary only in cases in which pleural levels of ADA are below 47 U/l, pleural fluid cytology is negative and, in the absence of a positive basis for some other diagnosis, neoplasia is suspected.     

Usefulness of thoracoscopic surgery in the diagnosis and management of thoracic diseases

BACKGROUND: Video-assisted thoracoscopic surgery (VATS) has been recently utilised in the diagnosis and management of thoracic diseases. In this article we report our series of patients with established indications for VATS treatment. METHODS: Over the past 6 years we performed 104 VATS procedures for diagnostic and therapeutic purposes in 95 men and 39 women. The specific indications for VATS were: lung biopsy for undiagnosed diffuse lung disease, mediastinal biopsy and cysts, pleural effusion, empyema, pneumothorax and bullous lung disease, pericardial effusion and cyst, parvertebral abscess and solitary pulmonary nodules. RESULTS: There was no operative mortality. Postoperative non-fatal complications were seen in 7 cases. The overall median duration of chest tube drainage was 2.5 days and the mean postoperative stay 3 days. In diffuse lung disease a tissue diagnosis was obtained in all cases. Definitive diagnosis in the patients with undiagnosed pleural effusion was obtained in 90% of cases and the overall diagnostic rate was 98.5%. The success rate of the empyema (stage II) treatment and the therapeutic procedures is 100% after a mean follow-up of 12 months (range 6-30). Conversion to thoracotomy was needed in 6 cases. In all patients the postoperative pain was controlled with intake of non-narcotic analgesics with satisfactory results. CONCLUSIONS: VATS is worth considering and has been established as procedure of choice, with exceptional results in various chest diseases such as undiagnosed pleural effusions, recurrent, post-traumatic or complicated spontaneous pneumothorax, stage II empyema, accurate staging for lung cancer in the resection of peripheral solitary pulmonary nodule less than 3 cm, and lung biopsy for pulmonary diffuse disease.     

Direct detection by ligase chain reaction of Mycobacterium tuberculosis complex in pleural fluid

Our purpose was to investigate the utility of the DNA amplification by ligase chain reaction (LCR) for the direct detection of Mycobacterium tuberculosis complex (MTC) in pleural fluid specimens from patients suspected for tuberculous pleural effusion. We have used the LCx M. tuberculosis kit (Abbott) which uses the amplification of the gene that encodes for antigen b. We have examined 81 pleural fluid specimens by isolation (on L?wenstein-Jensen medium and MB/BacT system) and by LCR. Out of 10 positive specimens in culture, 4 were also positive by LCR; out of 71 negative specimens in culture, 8 were positive by LCR. We have re-evaluated the LCR results according to the clinical diagnosis, sustained by the successful therapy, and to the pathological diagnosis on the pleural biopsy. The sensitivity and specificity of LCR in the diagnosis of tuberculous pleural effusion were 31.5% and 100%. This commercial LCR kit is a rapid, specific, but less sensitive test for the routine diagnosis of the tuberculous pleural effusion.     

Infection of the pleura by Aspergillus fumigatus

Pleural aspergillosis occurs mostly in established cases of pleural empyema with a broncho-pleural fistula. Ten such patients are reported here: in all, Aspergillus fumigatus infection was related to tuberculosis. In three cases with an active, sputum-positive tuberculous process the pleural empyema was a complication of spontaneous pneumothorax in two, and of lung resection in one. In two cases the empyema occurred as a complication of tuberculous pleuritis, but A. fumigatus infection was noted only after the sputum had become negative for tubercle bacilli. In five patients with inactive tuberculosis, the empyema was a late complication of pneumothorax therapy. The diagnosis of pleural aspergillosis is made on the basis of microscopical examination and culture of A. fumigatus in the pleural pus. The cultures were positive in seven of the 10 cases presented. In two cases in which the culture was negative microscopical examination of the pus revealed the presence of numerous fungal hyphae which was evidence of fungal necrosis. In one case the diagnosis was not made until necropsy. Serum precipitin tests with filtrates of A. fumigatus are further valuable evidence of aspergillous infection. Of 10 presented patients, this test was positive in all seven cases in which it was done. The treatment of pleural aspergillosis by local instillation of nystatin or amphotericin B was effective in six out of seven cases in which it was used.     

Pleural effusion: laboratory tests in 300 cases.

The cause of pleural effusion was studied in 300 consecutive patients by clinical examination and laboratory tests. The three most common causes were found to be cancer 117 cases (metastatic 65, bronchogenic 34, mesothelioma 10, lymphoma 7, other 1); tuberculous infection 53; and bacterial infection 38. The cause was not found in 62 patients. Cancer diagnosis was established by cytological examination of pleural fluid (63), closed pleural biopsy (37), and open pleural biopsy (11). Tuberculosis was diagnosed by culture of pleural fluid (12), closed pleural biopsy (38), and open pleural biopsy (3). In cases of empyema 12 Gram-positive and two Gram-negative cocci and two anaerobes were identified. The various causes and the usefulness of the different investigative procedures are discussed, and the data evaluated in the light of current knowledge about mechanisms of transfer through the pleural space.     

胸腔镜辅助治疗早期结核性包裹性胸腔积液112例

目的：探讨胸腔镜辅助治疗结核性包裹性胸腔积液的效果。方法2003年10月～2012年9月，对112例早期结核性包裹性胸膜炎并胸腔积液患者行胸腔镜辅助治疗，将包裹分隔用胸腔镜活检钳及电凝钩分离，清除分隔内的干酪坏死组织、纤维板及胸腔积液，胸腔内放置中心静脉导管，术后用尿激酶溶解纤维素。术后给予抗结核药物治疗。结果111例肺完全复张，1例右下肺未完全膨胀。2例术后其他细菌感染，经抗生素治疗痊愈。112例随访9～12个月，平均9．4月，无复发。结论对内科反复穿刺及置管引流不.的早期结核性包裹性胸腔积液，胸腔镜辅助手术治疗安全有效，无明显并发症。     

Video-assisted thoracoscopic surgery in the diagnosis and treatment of chest diseases

Video-assisted thoracoscopic surgery (VATS) has been used recently in the diagnosis and management of thoracic diseases. In this report, VATS experience with 95 cases, focusing on indications, surgical procedures, complications, and failure rates, are reviewed. Over the past 5 years, 95 VATS procedures for diagnostic and therapeutic purposes were performed in 59 men and 36 women. The specific indications for VATS were lung biopsy for undiagnosed diffuse lung disease (48), mediastinal biopsy (12) and cyst (2), pleural effusion (10), empyema (5), pneumothorax and bullous lung disease (6), pericardial effusion (2) and cyst (2), paravertebral abscess (2), solitary pulmonary nodules (3), and thoracic trauma (3). In all patients, postoperative pain was controlled with non-narcotic analgesics and was measured according to the visual analogue scale (VAS). There was no surgical mortality. Postoperative nonfatal complications were seen in seven cases (7.5%). The overall median duration of chest tube drainage was 2.7 days and the mean postoperative hospital stay was 3 days. For diffuse lung disease, a tissue diagnosis was obtained in all the cases. Definitive diagnosis in the patients with undiagnosed pleural effusion was obtained in 90% of cases, and the overall diagnostic rate was 98.5%. The success rate of the therapeutic procedures was 100% after a mean follow-up of 12 months (range, 6-30 months). Conversion to thoracotomy was needed in six cases (6.6%). All patients scored postoperative pain <50% according to the VAS. Video-assisted thoracoscopic surgery should be considered as a procedure of choice, with exceptional results in the following chest diseases: (a) undiagnosed pleural effusions; (b) recurrent, post-traumatic, or complicated spontaneous pneumothorax; (c) stage II empyema; (d) accurate staging of lung cancer; (e) emergency traumatic injuries of the chest; (f) peripheral solitary pulmonary nodule <3 cm; and (g) lung biopsy for pulmonary diffuse disease.     

电视胸腔镜在不明原因胸腔积液诊治中的价值

目的评价电视胸腔镜在不明原因胸腔积液诊治中的价值。方法2002年3月～2005年3月对常规检查无法明确病因的45例胸腔积液在电视胸腔镜下完成活检或纤维板剥脱、胸膜固定。结果45例全部确诊，其中恶性3例，结核性胸腔积液38例，非特异性胸腔积液3例，特发性胸腔积液1例。45例随访2～36个月，平均18个月，无胸腔积液复发。结论电视胸腔镜手术诊治胸腔积液具有诊断率高、安全、准确、损伤小的特点。     

Mesothelioma – VATS biopsy and lung mobilization improves diagnosis and palliation

Objectives: Mesothelioma is an increasingly frequent malignancy in which diagnosis is often delayed and disease diagnosed at an advanced stage. Earlier diagnosis and therapeutic intervention that can control recurrent pleural effusion may improve outlook and survival. Methods: A prospective series of 25 patients in whom mesothelioma was suspected was referred for histological diagnosis by video assisted-thoracoscopy (VAT) after failure of other methods. At the same operative procedure drainage of pleural effusion, cytoreductive pleurectomy and lung mobilization was performed where possible. Complete follow-up was obtained. Results: All patients had a histological diagnosis (100%) from the material sent for biopsy. In 23 patients this was mesothelioma, in two patients chronic empyema. All patients undergoing drainage of effusion, cytoreductive pleurectomy and lung mobilization subsequently were diagnosed of having mesothelioma stages III to IV. Fifteen out of 21 who underwent lung mobilization had closure of the pleural space. Post operative air leak in this group was a mean of 5 days (2–12 days). Recurrent effusion occurred in only one patient. Eleven patients remain alive at 1–2 years post operation with no hospital admissions for recurrent pleural effusion. In the six out of 21 who did not have closure of the pleural space, one remained alive 9 months post surgery. Five died within 1–6 months of the procedure. The average number of further hospital admissions for repeat drainage of effusion was 3 (1–6). Conclusions: VATs provides adequate tissue for histological diagnosis where other methods fail. At the same operative sitting it provides a therapeutic intervention that allows drainage of effusion cytoreductive pleurectomy and lung mobilization in a significant number of cases. Where the pleural space can be closed this results in significantly fewer hospital admissions and appears to improve quality of life and length of survival. The price is a longer hospital stay due to prolonged air leak.     

Diagnostic value of thoracoscopic pleural biopsy for pleurisy under local anaesthesia

BACKGROUND: We find pleural effusion in clinical practice frequently. However, it is difficult to make a diagnosis definitively by thoracocentesis or closed pleural biopsy. We directly examine the thoracic cavity by thoracoscopy under local anaesthesia, carry out pleural biopsy and make a definitive pathological diagnosis in pleurisy. METHOD: A retrospective study of 138 patients who had been diagnosed by thoracoscopy in our hospital was carried out between January 1995 and January 2005. RESULTS: The patients were 114 men and 24 women, ranging in age from 21 to 85 years, with a mean of 59 years. The right side was involved in 83 patients and the left side in 55. The operations took 11-145 min, with a mean of 46 min. Thoracoscopy directly without thoracocenteses was carried out in 28 of 138 patients. Lung cancer with pleural dissemination was diagnosed in 27, malignant pleural mesothelioma in 10, tuberculous pleurisy in 32, non-specific pleurisy in 58, other tumour in 2 and pyothorax in 9 patients. The overall diagnostic efficacy was 97.1% (134/138). The diagnostic efficacy in the cases of carcinoma was 92.6% (25/27), in malignant pleural mesothelioma it was 100% (10/10) and in tuberculosis it was 93.8% (30/32). No major complications occurred during the examination. CONCLUSION: Pleural biopsy by thoracoscopy under local anaesthesia should be actively carried out in patients with pleurisy, because the technique has a high diagnostic rate and can be easily and safely carried out.     

Diagnostic dilemma of tuberculosis in the foot and ankle

BACKGROUND: Isolated involvement of bone in tuberculous infection is uncommon, and the variable clinical and radiological features may mimic pyogenic osteomyelitis, bone tumor or other inflammatory and neoplastic processes of the synovium. We have reported our experiences with the diagnosis of tuberculosis infection in the ankle and foot with the hope of providing sufficient information about these cases to lead to early diagnosis. MATERIALS AND METHODS: We treated 15 patients with tuberculosis involving the foot and ankle between 1995 and 2005. They were followed for a minimum of 24 months, and the average duration of symptoms was 23 months. All patients underwent a physical examination, routine laboratory tests, plain radiographs, and a biopsy of the infection site. MRI studies were performed in 10 patients and a CT scan was done in one patient. RESULTS: The lesions were located in the forefoot (2), midfoot (3) and ankle (10). From the imaging studies, the presumptive preoperative diagnoses were tuberculous osteomyelitis (7), pyogenic osteomyelitis (4), pigmented villonodular synovitis (2), amyloidosis (1), and avascular necrosis of the talus (1). These diagnoses were verified by granulomatous inflammation with or without caseous necrosis on histology and tubercle bacilli were cultured in four cases. In three cases the diagnosis was made by polymerase chain reaction (PCR). CONCLUSION: When a patient presents with a localized, painful swelling and a persistent draining sinus of the foot and ankle, tuberculosis should be considered in the differential diagnosis. Additionally, we highly recommend taking a biopsy of the site of suspected infection because an early diagnosis is the key to successful treatment.     

Single access videothoracoscopic biopsy and talc pleurodesis in patients with malignant pleural effusion

Aim-Background

Recurrent pleural effusion is frequently observed in clinical experience and malignancy is one of the most frequent causes. Although it is generally necessary to prevent the recurrence of effusion in patients with disseminated neoplastic disease, in others, a diagnosis is required. The aim of this study was to determine the efficacy and safety of biopsy and pleurodesis by a single access videothoracoscopic approach.

Methods

We report a consecutive series of 20 patients (12 men, 8 women, aged 39 to 83 years) who underwent single access videothoracoscopy with pleural biopsy and talc pleurodesis for recurrent pleural effusion. In all cases, indication for the procedure was a recurrent pleural effusion, suspicious for malignancy. Videothoracoscopy was performed under general anaesthesia. For pleurodesis, an average of 8g of sterile talc powder was used. A six-month follow-up was completed for all patients, and efficacy was judged by clinical examination and chest X-ray.

Results

Diagnosis was obtained in all cases. In five cases, the diagnosis was a pleural involvement by breast cancer metastasis, and in four cases, a primary lung cancer was detected. Eight were mesotheliomas and one a parapneumonic collection. In two cases, an unknown-malignancy recurrent pleural effusion was observed. No deaths, talc-induced ARDS or malignant invasion of the scar occurred, but only a postoperative empyema and two subcutaneous emphysemas treated successfully without further operation.

Conclusions

Single access videothoracoscopic pleural biopsy and talc pleurodesis is a safe and effective method for the diagnosis and treatment of malignant pleural effusions.     

Intrathoracic tuberculous lymphadenopathy: clinical and bronchoscopic features in 17 adults without parenchymal lesions.

BACKGROUND: Whilst intrathoracic lymphadenitis is a characteristic sign of primary tuberculosis in children, its presence without parenchymal lesions in adults is unusual and makes the diagnosis using noninvasive techniques difficult. The diagnostic role of bronchoscopy in adults with intrathoracic tuberculous lymphadenitis is reported. METHODS: Seventeen patients with intrathoracic lymphadenopathy seen during 1993 who had all undergone bronchoscopy and had been found to have tuberculosis in the absence of any parenchymal lung lesions were evaluated retrospectively. RESULTS: Right paratracheal lymphadenopathy was observed on the plain chest radiograph in all the patients. Fifteen of the 17 patients had an endobronchial abnormality and samples taken at bronchoscopy gave a definitive diagnosis in nine (53%) of the 17. Four patients had ulcerating endobronchial granuloma and all had biopsy samples positive for tuberculosis. Transbronchial or transcarinal needle aspiration samples were diagnostic in five of 11 patients (45%) subjected to the procedure. Peripheral lymph node biopsy diagnosed tuberculosis in two cases and in the remaining six patients the diagnosis wa achieved by mediastinoscopy or thoracotomy. CONCLUSIONS: Bronchoscopy has an important role in the diagnosis of intrathoracic tuberculous lymphadenopathy in adults and should be considered before other invasive procedures.     

胸膜间皮瘤的诊断与治疗

经手术病理证实的胸膜间皮瘤１８例，其中良好性１５例，恶性１３例，局限型７例，弥漫型１１例。本病术前误诊率高，本组误诊８例。１９例均行手术治疗，术后３例失访。本病诊断主要依靠胸水的检查和胸膜活检；局限型胸膜间皮瘤一经确诊，主张早期手术；弥漫型确诊后如患者全身情况允许，应行广泛手术切除及术后综合治疗，以利于延长患者生命。     

γ-干扰素释放试验联合胸膜组织活检用于诊断结核性胸膜炎的评估

目的：评价全血γ-干扰素释放试验联合胸膜活检对结核性胸腔积液诊断的应用价值。方法应用全血γ-干扰素释放试验QuantiFERON-TB Gold In Tube（QFT-GIT）对79例胸腔积液患者进行检测,其中结核性胸腔积液患者45例,非结核性胸腔积液患者34例,结核合并肿瘤患者1例。同时,对其中27例患者进行胸腔镜下胸膜组织活检。结果结核性胸腔积液组,QFT-GIT的阳性率为91.1%（41/45）,非结核性胸腔积液组的阳性率为26.5%（9/34）。QFT-GIT试验诊断结核性胸腔积液的敏感性为91.1%（41/45）,特异性为73.5%（25/34）,阳性预测值为82.0%,阴性预测值为89.3%;胸膜组织活检诊断结核性胸膜炎的敏感性为96.3%（26/27）,特异性为100.0%（12/12）。联合胸膜活检诊断结核性胸膜炎的敏感性为95.5%（42/44）,特异性为94.1%（32/34）。结论全血γ-干扰素释放试验QFT-GIT联合胸膜组织活检用于诊断结核性胸腔积液具有较高的敏感性和特异性,在我国具有较高的临床应用价值。     

Pleuroscopy in the preoperative staging of bronchial cancer

The use of pleuroscopy or thoracoscopy in preoperative staging and resectability assessment of lung cancer is uncommon. Diagnostic and exploratory thoracoscopy could be helpful in three circumstances: when malignant pleural effusion is suspected with a lung cancer, while all the initial investigations remain negative: (cytology, needle-biopsy); in cases with radiological images (using CTs-can or MRI) of small metastatic pleural masses without effusion: thoracoscopy is performed after creating a pneumothorax; when mediastinal or hilar extension of the tumor and lymph-nodes (especially in the left superior mediastinum) cannot be reached for biopsy by mediastinoscopy or parasternal mediastinotomy. The investigation is performed under general anesthesia using double-lumen selective intubation and lung exclusion. This procedure provides a better view of the pleural space and mediastinal and hilar areas; macroscopic involvement of vital structures, organs or vessels can be easily seen and large biopsy specimens safely taken, without any postoperative morbidity. Talc insufflation for pleurodesis is added in patients with massive pleural effusion. Failures of the method or false-negative biopsies are related to previous pleurodesis, pleural partition, or adhesions. The contribution of CT scan and MRI imaging is mandatory to determine indications and to select the best endoscopic approach.     

电视胸腔镜诊治胸腔积液的临床体会

目的:探讨电视胸腔镜手术诊治胸腔积液的应用价值。方法:回顾分析2006年3月至2012年8月为152例胸腔积液患者行电视胸腔镜手术的临床资料。双腔气管插管全麻后置入胸腔镜及活检钳,取胸膜组织送病理检查,并根据病理检查结果决定治疗方案。结果:152例患者中肺癌胸膜转移83例,恶性胸膜间皮瘤18例,胸腺瘤3例,恶性肿瘤胸膜转移16例,来源不明的转移肿瘤4例,结核性胸水25例,3例未明确诊断。恶性胸腔积液患者行滑石粉胸膜固定,根据病理类型术后予以规范化抗肿瘤治疗。结核性胸腔积液患者,术后予以正规抗结核治疗。余者均根据病理回报结果进行相应后续治疗。结论:电视胸腔镜手术诊治胸腔积液微创,确诊率高,疗效确切,为进一步治疗疾病提供了有力证据。     

Interferon gamma for diagnosing tuberculous pleural effusions

BACKGROUND: A study was undertaken to evaluate the diagnostic value of pleural fluid concentrations of interferon gamma (IFN-gamma) as a marker of tuberculosis. METHODS: Patients admitted to King Chulalongkorn Memorial Hospital between April 1997 and January 1998 with a lymphocytic exudative pleural effusion were enrolled into the study. The pleural fluids were examined for cytology, staining for acid fast bacilli, and mycobacterial culture. Pathological examination and mycobacterial culture were performed on each pleural biopsy specimen. The diagnosis of tuberculosis was made when one of the following criteria was met: (1) Mycobacterium tuberculosis was isolated from either the pleural fluid or pleural tissue; (2) granulomas were demonstrated in the pleural tissue which stained positive for acid fast bacilli (AFB); or (3) in the presence of granulomas negative on staining for AFB in pleural tissue there was a response to antituberculous treatment on follow up. All pleural fluid samples were stored at -70 degrees C and the IFN-gamma level was measured by immunoassay. Analysis was made using sensitivity, specificity, and likelihood ratio for a positive test result. The best cut off point was determined by the highest likelihood ratio and receiver operating characteristic curve. RESULTS: A total of 66 patients were enrolled and tuberculosis was confirmed in 39 of them. The diagnoses in the non-tuberculous group included malignancy (15), paramalignancy (11), and chronic pleuritis secondary to infective endocarditis (1). The mean (SE) IFN-gamma level in the pleural fluid was significantly higher in the tuberculous group than in the non-tuberculous group (1493.3 (131.3) pg/ml versus 80.1 (50.4) pg/ml, p<0.001). The overlap between the two groups was minimal. At the cut off value of 240 pg/ml the sensitivity was 94.9% (95% CI 86.6 to 100), the specificity was 96.3% (95% CI 89.2 to 100), and the likelihood ratio for a positive test result was 25.6. CONCLUSIONS: The pleural fluid concentration of IFN-gamma is a good and useful diagnostic marker of tuberculosis presenting as a lymphocytic exudative pleural effusion.     

Thoracic lymphadenopathy in Asians resident in the United Kingdom: role of mediastinoscopy in initial diagnosis.

Although the incidence of superficial glandular tuberculosis is high in Asian immigrants, a clinical diagnosis without biopsy has previously been shown to be inaccurate in 22% of cases. The role of diagnostic mediastinoscopy and biopsy in thoracic lymphadenopathy was therefore evaluated in 41 consecutive Asian patients. Tuberculosis was diagnosed by histological examination or culture (or both) of gland biopsy material in 24 (59%). A further 12 patients, however, also received antituberculous chemotherapy, with a response in 10 cases. If these are included, 34 (83%) were finally considered to have tuberculosis. The symptoms and ages of the patients with tuberculosis were similar to those typically seen in caucasians with sarcoidosis. Six had tuberculous bilateral hilar lymphadenopathy. In only four cases (10%) was a positive diagnosis other than tuberculosis established; in two (lymphoma and thymoma) mediastinoscopy confirmed preoperative suspicions, and saved only two more (with sarcoidosis and vascular anomaly) from unnecessary antituberculous treatment. Complications included severe haemorrhage (1) and chronic tuberculous sinus in the endoscopy tract (2). Mediastinoscopy is unlikely to change management in most patients, produces an appreciable amount of morbidity, and should be reserved for cases in which there is additional clinical doubt. Any future decline in the prevalence of tuberculosis in Asians may, however, require its further evaluation.