a malignant pleural effusion is diagnosed by detecting exfoliated malignant cells in pleural fluid or demonstrating these cells in pleural tissue obtained by percutaneous pleural biopsy , thoracoscopy or thoracotomy . pleural effusion associated with malignancy in which there is no direct pleural involvement of the tumor and no other cause of effusion is found called para - malignant effusion . the simplest and minimally invasive way to establish the diagnosis of pleural malignancy thoracoscopy is the investigation of choice in pleural effusions where a diagnostic pleural aspiration is inconclusive . obviously it can not be performed routinely in a resource - poor country like india . closed pleural biopsy is less sensitive than pleural fluid cytology or thoracoscopy in evaluation of malignant pleural effusions . moreover about 7 - -12% of patients with malignant pleural effusion can be diagnosed by pleural biopsy when cytology is negative . our study was to evaluate the role of closed pleural biopsy in patients with malignant pleural effusions in a tertiary care centre where facilities for thoracoscopy are not available . a total of 66 cases with pleural effusions associated with malignancy admitted in the chest inpatient department of a tertiary care hospital between june 2007 and may 2008 were selected for the study . inclusion criteria were ( a ) age more than 18 years , ( b ) radiological evidence of pleural effusion , ( c ) evidence of malignancy in pleural fluid cytology or closed pleural biopsy , or cytological / histological evidence of malignancy in an extra - pleural site without evidence of malignancy in pleural fluid cytology or pleural biopsy . patients with chronic renal failure , bleeding diathesis , and anticoagulant therapy were excluded from the study . all patients were initially evaluated with detailed history , clinical examination , chest radiograph , and ct scan of thorax . the fluid was stained with papanicolaou stain and hematoxylin eosin stain and the stained smear was examined for the presence of malignant cell and type of malignancy . if the second sample was also negative , a third sample was examined for malignant cell . closed pleural biopsy was done using abram 's pleural biopsy needle under local anesthesia and four samples were obtained from each patient . if both cytology and histopathology were negative for malignancy , malignant etiology of the case was proved with any of the following procedures : biopsy of peripheral lymph node , ct - guided fine - needle aspiration cytology ( fnac ) of thoracic mass , fibreoptic bronchoscopic biopsy or ultrasonography - guided fnac of hepatic metastasis . there were 35 ( 53.5% ) males and 31 ( 46.5% ) females with age range between 28 and 74 years ( mean 52.3 years ) . chest x - ray showed massive pleural effusion in 14 ( 21% ) cases , concomitant mass lesions in 12 ( 18% ) cases , collapse in 12 ( 18% ) , and mediastinal lymphadenopathy in 6 ( 9% ) cases . ct scan of thorax revealed mass lesion in 26 cases ( 39% ) , collapse in 13 cases ( 20% ) , and mediastinal lymphadenopathy in 19 ( 29% ) cases . the first sample was positive in 35 patients ( 53% ) , second sample was positive in 10 patients ( 15% ) , but the third sample was positive only in 1 ( 1.5% ) patient . closed pleural biopsy showed malignant histology in 32 ( 48% ) cases and was negative in 34 ( 52% ) cases . results of pleural fluid cytology and pleural biopsy ( n = 66 ) out of the 46 cases where cytology was positive , the nature of malignancy could be ascertained in 34 patients . types of malignancy on basis of cytological study ( n = 46 ) adenocarcinoma was also the most common type of malignancy ( 65% ) on the basis of analysis of histopathological examination of pleural biopsy sample . other histological types were squamous cell carcinoma ( 3% ) , small cell carcinoma ( 6% ) , large cell carcinoma ( 3% ) , and indeterminate ( 23% ) . there were 22 cases where both pleural fluid cytology and pleural biopsy were positive . cytological - pathological concordance of these cases are as follows : ( a ) cytology and histology same in 12 ( 55% ) cases , ( b ) cytology inconclusive but histology diagnostic in 5(23%)cases , ( c ) cytology diagnostic but histology inconclusive in 3 ( 13% ) cases , and ( d ) cytology and histology giving different diagnosis in 2 ( 9% ) cases . all the five cases in which cytology was inconclusive , but biopsy yielded definite results were adenocarcinoma . among the three cases where cytology was conclusive but biopsy could not ascertain the type , two were adenocarcinoma and one squamous cell carcinoma . in the two cases with cytological -- histological nonconcordance , the cytological diagnosis was squamous cell carcinoma but the pleural biopsy revealed adenocarcinoma . in the 10 patients where both cytology and histopathology were negative , the presence of malignancy was ascertained by excision biopsy of lymph nodes ( n = 5 ) , fnac of lung mass under ct guidance ( n = 3 ) , usg - guided fnac from hepatic metastasis ( n = 1 ) and fibreoptic bronchoscopy ( n = 1 ) . the diagnostic yield of pleural fluid cytology has shown a wide variation ranging from 40% to 90%.[58 ] several factors influence the yield including mechanism of effusion , type of primary tumor , nature of specimens , number of specimens and the skill of the cyto - pathologists . para - malignant effusions will obviously have fewer yields than the malignant effusions . among the primary tumors diagnostic rate is higher in adenocarcinoma than in mesothelioma , squamous cell carcinoma , lymphoma , and sarcoma . if both cell blocks ( formed by centrifuging the sample and extracting the solid cellular portion ) and smears are prepared the yield becomes better than if only one method is used . one study found the yield of 65% , 27% , and 5% from the first , second , and third samples respectively . moreover , there is still controversy regarding the optimal amount of fluid to be submitted for examination . while one recent study showed that 60 ml of fluid produced better sensitivity than 10 ml , another previous study showed that sending fluid more than 50 ml did not improve the diagnostic yield . our study has confirmed the influence of almost all the factors in diagnostic yield . in our study the overall diagnostic yield was 70% , adenocarcinoma was the most common diagnosis ( 54% ) and the yield in the third fluid sample was significantly lower ( 1.5% ) than the first and second samples ( 53% and 15% respectively ) . we used both cell blocks and smears to increase the yield and submitted 50 ml of fluid in each patient to avoid the controversy of optimum amount of fluid . when pleural fluid cytology is negative in a suspected case of malignant pleural effusion , there are several options for further investigations like image - guided cutting needle biopsy , closed pleural biopsy , medical thoracoscopy , video - assisted thoracic surgery , and thoracotomy . in malignant pleural effusions , a review of pleural biopsy yield from 2893 examinations show a diagnostic yield of only 57% for malignancy . however the yield ranged from 40% to 75%.[1519 ] the relatively low yield of blind pleural biopsy is due to scarce , patchy and irregular distribution of the tumor invasion of the pleura . however studies have shown that 7% to 12% of patients with malignant effusions may be diagnosed by pleural biopsy when cytology is negative . contrast - enhanced thoracic ct scan will often show a focal area of abnormal pleura which can be biopsied with an image guided cutting needle biopsy . it has a higher diagnostic yield than that of blind pleural biopsy in diagnosis of malignant effusions . in a study the sensitivity of blind biopsy and cutting needle biopsy to diagnose malignancy was 47% and 87% respectively . but thoracoscopy is not available in most centers , is a costly procedure , has about 2.3% incidence of major complications , and needs hospitalization and thoracic surgery backup . thoracoscopy may also yield false negative results due to insufficient or nonrepresentative biopsy or presence of adhesions that prevent access to neoplastic tissue . it is opined that discouragement of closed pleural biopsy by western literature unfortunately translated into its decline in india . blind pleural biopsy is easily available , can be done on an outpatient basis , and has minimal complications in an experienced hand . it is a useful procedure specially when thoracoscopy is unavailable or the patient is too sick to tolerate thoracoscopy . moreover it is highly sensitive and cost - effective test to exclude unsuspected tuberculosis in a resource - poor country with a high incidence of tuberculosis . so there is necessity to redeem the practice of closed pleural biopsy among pulmonologists through proper awareness and encouragement . it is still highly relevant especially in a resource - limited country like ours where thoracoscopy is available only in few tertiary care centers of large cities .
background : pleural fluid cytology for malignant cells is the easiest way to diagnose malignant pleural effusion with good sensitivity and specificity . with the introduction of medical thoracoscopy , the use of closed pleural biopsy for the diagnosis of cytology negative malignant pleural effusion is gradually decreasing . 
 however use of thoracoscopy is limited due to its high cost and procedure related complications.aims:the aim was to assess the usefulness of closed pleural biopsy in the diagnosis of malignant pleural effusion.materials and methods : sixty - six patients of pleural effusion associated with malignancy were selected from the patients admitted in the chest ward of a tertiary care hospital over a period of 1 year . 
 pleural fluid aspiration for cytology and closed pleural biopsy were done in all the patients.results:out of 66 patients , 46 ( 69% ) patients showed malignant cells in pleural fluid cytology examination . 
 cytology was positive in 35 ( 52% ) , 10 ( 15% ) , and 1 ( 1.5% ) patients in the first , second , and third samples respectively . 
 closed pleural biopsy was positive in 32 ( 48% ) patients . among them , 22 also had positive cytology . 
 additional 10 cytology negative patients were diagnosed by pleural biopsy . 
 cytology 
 histology concordance was seen in 12 patients . 
 definite histological diagnosis could be achieved in five patients with indeterminate cytology . 
 pleural biopsy was not associated with any major postoperative complication.conclusion:closed pleural biopsy can improve the diagnostic ability in cytology negative malignant pleural effusion . 
 closed pleural biopsy has still a place in evaluation of malignant pleural effusion especially in a resource - limited country like india .