Abstract Objective: The incidence of tuberculosis worldwide has emphasized the need for better assays designed to diagnose the disease, principally the extrapulmonary form. The objective of the present study was to validate the performance of an automated method for the determination of adenosine deaminase (ADA) activity in pleural fluid (PF) and cerebrospinal fluid (CSF), comparing it with a conventional method (the modified Giusti method). Methods: In total, 134 samples were selected from among those tested in our laboratory: 94 PF samples and 40 CSF samples. The ADA activity was determined using the two methods. Inter- and intra-assay precision was determined, linear regression analysis was performed, simple concordance tests were conducted, and the means of the differences were calculated. Results: The correlation coefficients for PF and CSF samples were, respectively, 0.96 and 0.95. Inter-assay precision was determined using 21 replicates at 3 different activity levels: low, medium and high. The percentage coefficient of variation (%CV) was, respectively, 5.9, 8.1 and 5.8 for PF samples, compared with 21.9, 18.6 and 13.8 for CSF samples. Intra-assay precision in %CV was 1.3 and 11.7, respectively, for PF and CSF samples. The concordance between the methods in PF and CRF samples was, respectively, 96.8% and 100%, considering the reference values for the diagnosis of TB to be 40 U/L (conventional) and 30 U/L (automated) in PF samples, versus 9 U/L (for both methods) in CSF samples. Conclusions: The results validate the use of the automated method of determining ADA activity in PF and CSF samples as an alternative to the conventional method.

Keywords: Adenosine deaminase; Tuberculosis/diagnosis; Pleural effusion; Cerebrospinal fluid.

Objective: To evaluate Brazilian studies by summarizing the accuracy of adenosine deaminase in the diagnosis of the pleural tuberculosis, with the objective of lending support to the movement to make the test part of the routine in the investigation of pleural effusions. Methods: A search for Brazilian studies related to the determination of adenosine deaminase levels in the pleural liquid was carried out. These studies were evaluated and included in this study. The data were analyzed using summary receiver operating characteristic (SROC) curves, which enabled the studies to be collected and evaluated regarding the accuracy of the diagnosis. As for the global values of sensitivity and specificity, the Bayes' theorem was applied to calculate the post-test probabilities in different prevalences of the disease. Results: Twenty-five studies dating from 1987 to 2005 and including enough information to be used in the meta-analysis were identified. After evaluation, nine studies were included, totaling 1674 patients. According to the SROC curve, a sensitivity of 91.8% (95% CI: 89.8‑93.6%) and a specificity of 88.4% (95% CI: 86.0-90.5%) were found, with an area of 0.969 below the curve. The overall odds ratio was 112.0 (95% CI: 51.6-243.2). Considering a prevalence of tuberculosis of 50% (considered neutral), the post-test probability was 88.7% for a positive test and 91.5% for a negative test. Conclusion: Despite the differences found among studies, it is possible to conclude that the determination of adenosine deaminase levels has high accuracy in the diagnosis of the pleural tuberculosis and should be used as a routine test in its investigation.

Keywords: Pleural effusion; Tuberculosis; Diagnosis; Adenosine deaminase; Meta-analysis.

Background: The diagnosis of pleural tuberculosis continues to be a challenge due to the low sensitivity of traditional diagnostic methods. Histopathological examination of pleural tissue is the most accurate method, with a sensitivity of up to 80%. Determination of adenosine deaminase levels is a recently introduced method, although its usefulness in the diagnosis of pleural tuberculosis in Brazil has yet to better elucidated. Objective: To verify the sensitivity and specificity of an experimental method of measuring adenosine deaminase activity in pleural fluid in a series of patients with pleural effusion patients evaluated between August 1998 and November 2002 in Rio de Janeiro (RJ). Results: Out of 137 cases, 111 pleural fluid samples were available. Of those, 83 were from pleural tuberculosis patients. Among the 67 pleural tuberculosis patients tested, 10 (14.9%) presented human immunodeficiency virus. The adenosine deaminase cutoff value of 35U/L was determined by a receiver operator characteristic curve. The sensitivity, specificity and likelihood ratios (positive and negative) were 92.8%, 93.3%, 25.8 and 13.9, respectively. Mean adenosine deaminase in the pleural tuberculosis group was 84.7 ± 43.1 U/L, versus 15.9 ± 11.1 U/L in the group with other diseases. There was no significant difference in adenosine deaminase activity between patients with and without human immunodeficiency virus co-infection. Conclusions: Adenosine deaminase measurement in pleural fluid is a sensitive and specific method for the diagnosis of pleural tuberculosis and its use can preclude the need for pleural biopsy in the initial workup of pleural effusion patients. An adenosine deaminase cutoff value of 35U/L is recommended.

Keywords: Pleural fluid. Adenosine deaminase. Diagnosis. Tuberculosis. HIV

Objective: To evaluate the accuracy of determining the adenosine deaminase (ADA) level, the 2'-deoxyadenosine/ADA ratio, and the LDH/ADA ratio in pleural fluid for the diagnosis of pleural tuberculosis (PT) in children and adolescents. Methods: This was a retrospective cross-sectional study conducted at a tertiary hospital in a high-tuberculosis-incidence area, between 2001 and 2018. All patients with ADA in pleural fluid and a confirmed diagnosis of PT (cPT) or parapneumonic effusion (PPE) were included. Results: The cPT and PPE groups comprised 25 and 68 individuals, respectively. At a cutoff of 40 U/L, ADA measurement showed the following: sensitivity, 88%; specificity, 31%; positive predictive value (PPV), 32%; negative predictive value (NPV), 88%; and overall accuracy, 46%. The best cutoffs were an ADA level of 125 U/L, a 2'-deoxyadenosine/ADA ratio of 0.5, and an LDH/ADA ratio of 8.3, with AUC of 0.67, 0.75, and 0.82, respectively. The sensitivity, specificity, PPV, NPV, and overall accuracy of the 125 U/L ADA cutoff were 84%, 65%, 47%, 92%, and 70%, respectively, compared with 79%, 79%, 59%, 91%, and 79%, respectively, for the 8.3 LDH/ADA ratio cutoff. Changing the LDH/ADA ratio cutoff to 3.0 increased the specificity to 98%. Conclusions: The ADA level and the 2'-deoxyadenosine/ADA ratio are not good biomarkers for the diagnosis of PT in pediatric patients. Determination of the LDH/ADA ratio provides the best overall accuracy for the diagnosis of PT in such patients.

Keywords: Adenosine deaminase; Pleural effusion; Tuberculosis, pleural/diagnosis; Child; Adolescent.

Ovarian hyperstimulation syndrome (OHSS) is an iatrogenic complication that occurs in the luteal phase of an induced hormonal cycle. In most cases, the symptoms are self-limited and spontaneous regression occurs. However, severe cases are typically accompanied by acute respiratory distress. The objective of the present study was to describe the clinical presentation, treatment, and outcome of pleural effusion associated with OHSS in three patients undergoing in vitro fertilization. The patients ranged in age from 27 to 33 years. The onset of symptomatic pleural effusion (bilateral in all cases) occurred, on average, 43 days (range, 27-60 days) after initiation of hormone therapy for ovulation induction. All three patients required hospitalization for massive fluid resuscitation, and two required noninvasive mechanical ventilation. Although all three patients initially underwent thoracentesis, early recurrence of symptoms and pleural effusion prompted the use of drainage with a pigtail catheter. Despite the high output from the pleural drain (mean, 1,000 mL/day in the first week) and prolonged drainage (for 9-22 days), the outcomes were excellent: all three patients were discharged from hospital. Although pleural effusion secondary to OHSS is probably underdiagnosed, the associated morbidity should not be underestimated, especially because it affects potentially pregnant patients. In this study, early diagnosis and appropriate supportive measures yielded favorable results, limiting the surgical approach to adequate pleural drainage.

Keywords: Fertilization in vitro; Ovarian hyperstimulation syndrome; Pleural effusion.

Malignant mesotheliomas are rare types of cancers that affect the mesothelial surfaces, usually the pleura and peritoneum. They are associated with asbestos exposure, but due to a latency period of more than 30 years and difficult diagnosis, most cases are not detected until they reach advanced stages. Treatment options for this tumor type are very limited and survival ranges from 12 to 36 months. This review discusses the molecular physiopathology, current diagnosis, and latest therapeutic options for this disease.

Keywords: Pleural Mesothelioma; Treatment; Molecular Alterations.

The authors report a case of pleural lipoma which was found incidentally in a thoracic roentgenogram. The radiographic studies were inconclusive about the nature of the lesion. The diagnosis was established by histologic study of the tumor excised by thoracotomy, after an inconclusive cytologic study obtained by transthoracic fine needle aspiration.

Keywords: Lipoma. Pleura.

The authors report a case of pancreatic pseudocyst associated with massive pleural effusion. The patient was submitted to X rays, REED, ultrasonography, thoracoabdominal computerized tomography and amylase dosing in the pleural liquid. Clinical treatment included dietary support and thoracocentesis with drainage of about 3,200 ml. Patient was submitted to laparotomy to remove the pseudocyst, and was discharged in good clinical conditions. Based on this report, the authors analyze and review the literature for the occurrence of pleural effusion associated with pancreatic diseases and diagnoses.

Keywords: Pancreatic pseudocyst. Pleural effusion. Computerized X-ray tomography. Laparotomy.

Mycobacterium kansasii, a nontuberculous mycobacterium, can cause pulmonary disease presenting clinical and radiological similarities to tuberculosis. M. kansasii infection has been associated with risk factors such as bronchiectasis, chronic obstructive pulmonary disease, tuberculosis sequelae, pneumoconiosis and immunosuppression. Herein, we describe a case of pleural effusion in a 67-year-old patient with chronic obstructive pulmonary disease and a history of pulmonary tuberculosis. The histological analysis demonstrated a granulomatous chronic process and acid-fast bacilli positivity, suggesting a diagnosis of pleural tuberculosis. M. kansasii was detected both in pleural fluid cultures and in cultures of tissue samples. We discuss the differential etiologic diagnosis with other infectious agents of granulomatous diseases, and we address treatment options.

Keywords: Mycobacterium kansasii; Mycobacterium infections; Pleural effusion; Case reports

Castleman's disease is a rare disorder of the lymphoid tissue. We report the case of a female patient with bilateral otosclerosis, no respiratory symptoms, and pleural effusion discovered as an incidental finding on a chest X-ray. Computed tomography of the chest revealed a mediastinal mass. The biopsy findings demonstrated that it was a plasmacytic variant of Castleman's disease. The patient underwent mediastinal mass resection. This resulted in near-total resolution of the effusion, which remained as a small loculation within the left pleural space.

Keywords: Giant lymph node hyperplasia; Pleural effusion; Case reports.

Claude Bernard-Horner syndrome presents various etiologies and occurs as the direct result of interrupted nerve signaling at any point along the nerve trajectory, be it intrathoracic or extrathoracic. Herein, we report a case of Claude Bernard-Horner syndrome caused by loculated pleural empyema located in the paravertebral region of the upper third of the right hemithorax. The patient was submitted to thoracotomy in order to drain the infected fluids. The end result was satisfactory, including resolution of the infection, pulmonary expansion, and remission of the syndrome.

Keywords: Pleural empyema/complications; Horner syndrome/etiology; Blepharoptosis; Thoracotomy;

Endometriosis is a benign gynecological disorder associated with pelvic pain and infertility, primarily affecting women of reproductive age. Thoracic endometriosis affects the pulmonary parenchyma or pleura. We report the cases of two patients with pleural endometriosis who presented with recurrent pneumothorax. In both cases, magnetic resonance imaging (MRI) of the chest showed right hydropneumothorax and well-defined, rounded nodules on the pleural surface in the right hemithorax. We conclude that MRI is a good option for the characterization of pleural endometriotic nodules and hemorrhagic pleural effusion.

Keywords: Endometriosis; Magnetic resonance imaging; Pneumothorax.

Objective: To evaluate the best time to perform thoracoscopy for the treatment of complicated parapneumonic pleural effusion in the fibrinopurulent phase in patients ≤ 14 years of age, regarding the postoperative evolution and occurrence of complications. Methods: This was a retrospective comparative study involving patients with parapneumonic pleural effusion presenting with septations or loculations on chest ultrasound who underwent thoracoscopy between January of 2000 and January of 2013. The patients were divided into two groups: early thoracoscopy (ET), performed by day 5 of hospitalization; and late thoracoscopy (LT), performed after day 5 of hospitalization. Results: We included 60 patients, 30 in each group. The mean age was 3.4 years; 28 patients (46.7%) were male; and 47 (78.3%) underwent primary thoracoscopy (no previous simple drainage). The two groups were similar regarding gender, age, weight, and type of thoracoscopy (p > 0.05 for all). There was a significant difference between the ET and the LT groups regarding the length of the hospital stay (14.5 days vs. 21.7 days; p < 0.001). There were also significant differences between the groups regarding the duration of fever in days; the total number of days from admission to the initiation of drainage; and the total number of days with the drain in place. Eight patients (13.6%) had at least one post-thoracoscopy complication, there being no difference between the groups. There were no deaths. Conclusions: Performing ET by day 5 of hospitalization was associated with shorter hospital stays, shorter duration of drainage, and shorter duration of fever, although not with a higher frequency of complications, requiring ICU admission, or requiring blood transfusion.

Keywords: Empyema, pleural; Thoracoscopy; Pneumonia.

Objective: To evaluate Light's criteria for drainage in children with parapneumonic pleural effusion. Methods: Prospective cross-sectional study on 85 children who were admitted to Hospital da Criança Santo Antônio, State of Rio Grande do Sul, Southern Brazil, presenting pneumonia with pleural effusion confirmed by chest X-ray and/or chest ultrasonography. The exclusion criteria were: previous drainage, pleural effusions associated with other disorders. The pH analysis was performed with a blood gas analyzer. Glucose and LDH were analyzed by spectrophotometry. The decision to perform pleural drainage was made by the attending physician without the participation of the researchers. Results: Pleural fluid in parapneumonic effusion with pH < 7.2 and glucose < 40 mg/dl presented higher drainage rate than LDH > 1,000 UI/l. The pH and glucose had high specificity (89% and 88%) and above the LDH (65%). The same results were observed when non-purulent fluids were analyzed (pH < 7.2 94%, glucose 88%, LDH 68%). In patients with pH < 7.2 LDH > 1,000 UI/l and glucose < 40 mg/dl predominated fluid with cloudy or purulent aspect. In more than 21% of patients who have indication of drainage by the classic criteria, was found limpid aspect. Conclusions: These data indicate that biochemical test support indication of drainage in children presenting with parapneumonic pleural effusion in non-purulent fluid. The specificity for drainage was 89% for pH and 88% for glucose and around 65% for LDH.

Keywords: Pleural effusion. Pleural empyema. Postural drainage.

A significant percentage of pleural effusions remains without a diagnostic explanation. In such circumstances, the anatomical-pathological result of nonspecific chronic pleuritis should be revised. This is an important issue, not only for the pathologist, but mainly for the pneumologist, who usually makes the clinical-pathological correlation during the routine practice. Although the existence of established criteria is accepted, they are certainly subjective and make the communication by means of a common language difficult, mainly among pathologists. The authors recently studied 311 pleural biopsies with histo-pathological diagnoses of chronic nonspecific pleuritis. All specimens were reviewed and the histo-pathological parameters quantified by stereology. The patients were stratified according to the final diagnosis of their disease, including cases of chronic renal failure, vasculitis, pancreatitis, tuberculosis, cancer, and congestive cardiac failure, in this case considering the pleura as normal. This procedure allowed us to obtain a discriminating model, whose morphological subcriteria classified almost 90% of the nonspecific chronic pleuritis biopsies, according to their final clinical diagnoses, which included true nonspecific chronic pleuritis or tuberculosis pleuritis, paraneoplastic pleuritis, or even normal pleura. By adding to this model the biochemistry or differential cytology of the pleural liquid, its classificatory power reaches 99% of correctness. This study represents the result of the experience acquired over several years in the histo-pathological interpretation of pleural biopsies, based on the correlation between morphology and biochemistry and cytology of the pleural fluid.

Keywords: Biopsy, needle. Pleura/pathology. Pleura/cytology. Pleural effusion.

Objective: To evaluate the safety and feasibility of the use of indwelling pleural catheters (IPCs) in patients with malignant pleural effusion (MPE). Methods: We prospectively collected data from patients with MPE undergoing IPC placement between January of 2014 and July of 2015. All patients submitted to IPC placement had a life expectancy > 30 days, in accordance with the MPE treatment guidelines established by the British Thoracic Society. The data collected included gender, age, body mass index, primary cancer site, duration of IPC drainage, IPC-related complications, length of hospital stay, pleural effusion recurrence, and occurrence of spontaneous pleurodesis. Results: A total of 19 patients underwent IPC placement during the study period. Median overall survival after IPC insertion was 145 days. The median follow-up among the surviving patients was 125 days (range, 53-485 days), and the median time between catheter insertion and removal was 31 days (range, 2-126 days). There were IPC-related complications in 5 patients (26.2%), and spontaneous pleurodesis was achieved in 8 (42.0%). Among those 8 patients, the IPC was removed between days 30 and 126 in 4, and spontaneous pleurodesis occurred within the first 30 days in 4. Conclusions: The use of IPCs seems to be feasible and safe in patients with MPE.

Keywords: Pleural effusion, malignant; Survival; Palliative care.