**6. Diagnosis**

Diagnostic success of cytology can improve with repeated thoracentesis [46]. Fluids should be concentrated first for optimal detection of malignancy. There is a large variation in diagnostic yields of pleural fluid cytology ranging from 62 to 90% [47, 48]. The sensitivity depends on the

Cytology of MPE in breast cancer has a sensitivity of 47% [50]. The diagnosis of adenocarci‐ nomas can be established in nearly all patients whereas patients with pleural effusions secondary to Hodgkin's disease, have a positive cytologic examination in less than 25% of cases [51, 52]. Cytology is superior to blind percutaneous pleural biopsy in the diagnosis of malig‐ nant pleural effusion. Blind percutaneous pleural biopsy carries an 8% risk of pneumothorax, and has limited contribution to the diagnosis of patient with suspected malignancy. In a series of 118 patients with pleural effusions and negative cytology, closed pleural biopsy established

Low diagnostic value of pleural biopsy depends on costal pleural involvement of cancer cells in only half of patients with MPE since initial metastatic disease most commonly occurs on the

After thoracentesis, pleural biopsy might be indicated in cases with cytological examination undiagnosedor suspected.Diagnosticvalueof conventional closedpleuralbiopsywithAbrams or Cope needles is lower when compared with image-guided and thoracoscopic biopsy techni‐ ques. The specificity of closed needle biopsy for MPE is high, but case series report sensitivities that range from 7% to 72% [53, 55-57]. However, closed pleural biopsy adds little to the cytolog‐ icaldiagnosisinmostcasesandthisisrelatedtothescarceandirregulardistributionofthetumour lesions in the pleural cavity when cytology is negative [54]. The yield of blind needle biopsy is higher when the pleural lesions are diffuse, as in tuberculosis and advanced neoplastic disease. In contrast, thoracoscopy has a very high yield in malignant effusions. It can be performed with localanesthesiaandasingleportofentry,andithasalittlemorecomplicationsthanneedlebiopsy [47]. Contraindications to pleural biopsy include bleeding diathesis, anticoagulation, chest wall infection, and lack of patient cooperation. Important complications include pneumothorax, haemothorax, and vasovagal reactions. A rapid clinical deterioration or increased postproce‐ dure effusion should alert the clinician to a possible haemothorax [58]. Nevertheless, pleural needle biopsy can be performed on outpatient basis [59] whereas thoracoscopy is much more

Normal pleural fluid pH ranges from 7.60 to 7.64. When a diagnostic thoracentesis is per‐ formed, pleural fluid pH is measured at any time. Analysis should be via a blood gas machine, not on litmus paper, because the latter is unreliable and not an acceptable alternative [60]. Approximately one-third of malignant effusions have a pleural fluid pH of <7.30 at presenta‐ tion [61, 62]; this low pH is associated with glucose values of <60 mg/dL [63]. The cause of these low-glucose, low-pH malignant effusion appears to be an increased tumour mass within the pleural space compared with those with a higher pH effusion, resulting in decreased glucose transfer into the pleural space and decreased efflux of the acidic by-products of glucose metabolism, carbon dioxide (CO2], and lactic acid, due to an abnormal pleural membrane [64, 65]. Clinicians should keep in mind that parapneumonic effusions have pH less than 7.3 or

type of malignancy, extent of disease, and experience of the cytopathologist [49].

the diagnosis of malignant pleural effusion in only 17% of the cases [53].

visceral, mediastinal, and diaphragmatic pleurae [54].

90 Principles and Practice of Cardiothoracic Surgery

complex and always requires hospitalization.

puslike looking.

MPE has a wide variety of diagnostic methods. Diagnostic methods are often chosen according to health care provider's medical facilities, the clinician's ability and most importantly the patient. In spite of all the advances in today's thoracic imaging confirmation of suspected malignant pleural effusion done by cytological methods or a pleural biopsy, a diagnostic thoracentesis is recommended for any unilateral effusion or bilateral effusion in an individual without obvious evidence of congestive heart failure [75]. Diagnostic thoracentesis is a useful initial approach for patients with MPEs. Thoracentesis takes place in diagnosis of MPE as well as reducing the symptoms. Thoracentesis also helps us in evaluation of the expansion capacity of the lung and relieving acute symptoms.

Traditionally, land selection for thoracentesis is determined by radiographic and physical examination findings [76]. There is no absolute contraindication for thoracentesis. Relative contraindications include a minimal effusion < 1 cm in thickness from the fluid level to the chest wall on a lateral decubitus view, bleeding diathesis, anticoagulation, and mechanical ventilation. There is no increased bleeding in patients with mild-to moderate coagulopathy or thrombocytopenia (prothrombin time or partial thromboplastin time >1.8 times normal, platelets <25,000/mm3 , or creatinine >6 mg/dL) [77]. Although it does not seem to increase the risk of pneumothorax in patients undergoing mechanical ventilation; if a pneumothorax occurs, the development of tension pneumothorax may be higher. Although the risk of pneumothorax rate is 10% in experienced hands, this risk increases in novices.

The sensitivity of medical thoracoscopy was higher than that of cytology and closed pleural biopsy combined (96 versus 74%, pv0.001). Similar results have been reported by other investigators [89-92]. The reasons for false-negative thoracoscopy include insufficient and nonrepresentative biopsies that depend largely on the experience of the thoracoscopist [89,

Management of Malignant Pleural Effusion http://dx.doi.org/10.5772/54441 93

The diagnostic yield of bronchoscopy is low in patients with undiagnosed pleural effusions and should not be undertaken routinely [93-95]. However, it is indicated when endobronchial lesions are suspected because of haemoptysis, atelectasis, or large effusions without contrala‐ teral mediastinal shift. Thoracotomy for diagnostic purposes is almost never indicated, because

Despite all the recent advances in cancer treatment management, MPE is suggestive of end stage disease with poor prognosis [51]. The mean survival is 3-6 months after diagnosis of malignant pleural effusion. Whereas, this period can take up to 4-12 months depending upon the histolog‐ ical subtype of the primary tumor such as in breast cancer, Hodgkin's disease, or lymphoma [98, 99]. The International Association for the Study of Lung Cancer reclassified MPE to the M1a descriptor,recognizingitspredictionforpoorlong-termsurvivalwithanoverall5-year survival rate of 7% [100]. In addition, patients with malignant effusions, and a pH of less than 7:30 with wickedprognosis, shortermediansurvival,andpoorerresponse totetracyclinepleurodesisand

On the other hand, malignant pleural effusion significantly affects the quality of life and reduced mobility of patients with malignant disease.The main goals of treatment for pleural

The aims of the treatment include drainage of pleural space, apposition of the visceral and pleural surfaces with complete expansion of the lung, and obliteration of the pleural surface with dispersion of a sclerosing agent throughout the pleural space [78]. Treatment options for malignant pleural effusion (MPE) are varied and often tailored to the clinician's specialty and expertise, the patient's physical performance status, hospitalization status, and individual

Selection of optimal treatment for each individual patient requires a careful assessment of the benefits and the risks of the treatment. Primary treatment targets should involve palliation or elimination of dyspnea, improvement of a patient's overall quality of life in order to restore daily activities, and implementation of oncological therapies [102]. Treatment options include repeat thoracentesis, tube thoracostomy with drainage and sclerosis with chemical sclerosant

92] and the presence of adhesions that prevent access to neoplastic tissue [87, 89].

less invasive methods can provide diagnosis in up to 97% of cases [89, 96, 97].

have a high rate of first finding of malignant cells in fluid cytology [61, 101]

effusion are to decrease symptoms and improve the quality of life [11].

**7. Prognostic factors**

**8. Treatment**

desires [78].

Important complications of thoracentesis include pneumothorax, bleeding, infection, and spleen or liver laceration. The amount of fluid drained during thoracentesis should be sufficient to obtain a diagnosis, relieve symptoms of dyspnea, and to avoid re-expansion pulmonary oedema or pneumothorax. The general belief and the guidelines proposed removal of more than 1500 ml in one hemithorax during a single transaction. However, this random number does not consider each patient's height and weight. As a general rule, the amount of fluid discharged from thoracentesis is 20 ml per kilogram of body weight [78]. On the other hand in recent studies, the risk of re-expansion pulmonary oedema was shown to be unrelated to the amount of drained fluid and it has been suggested that no upper limit is required [79].

Diagnostic thoracentesis is also useful in determining a patient's respiratory complaints that can be connected with effusion: Improvement in the patient's symptoms after thoracentesis indicates that the patient can take advantage of more invasive procedures and improve the quality of life. Persistence of respiratory symptoms in patients after thoracentesis, other causes should be investigated and before proceeding, more invasive diagnostic options should be considered twice.

The use of ultrasound guidance is preferred in thoracentesis. Ultrasound guidance, at the time of determining the location of the pleural fluids reduces accidental injury, and this technique to remove the liquid used to assess the degree of lung reexpansion [80].

Thoracoscopy should only be done in patients not diagnosed by less invasive procedures. Actual thoracoscopic techniques include video-assisted thoracoscopic surgery (VATS) [81] and medical thoracoscopy with either a rigid thoracoscope [82] or a semirigid pleuroscope [83, 84]. The advantages of thoracoscopy include visually directed and selective biopsies of parietal, mediastinal, and visceral pleura, direct visualization and examination of the entire hemithorax, and simultaneous lung or lymph node biopsy if required. The procedure is well tolerated with less than 1% mortality [85, 86].

Medical thoracoscopy when compared with surgical thoracoscopy (which is more precisely known as video-assisted thoracic surgery (VATS) has the advantage that it can be performed under local anaesthesia or conscious sedation, in an endoscopy suite, using nondisposable rigid instruments. Physicians skilled in bronchoscopy should find the semirigid pleuroscope easy to use because it has the same light source, video equipment, and manual controls as the fiberoptic bronchoscope [83, 84].Thus, it is considerably less invasive and less expensive than VATS. As an exception: VATS that allows huge biopsy samples can be taken, is preferred to medical thoracoscopy in patients with suspected mesothelioma. For diagnosis of mesothelio‐ ma and classification of its subtype, a large pleural biopsy specimen is often necessary. Immunohistochemical staining provides essential information in the diagnostic evaluation [6].

Medical thoracoscopy is primarily a diagnostic procedure [47, 87, 88]. In cases of undiagnosed exudative effusions with a high clinical suspicion for malignancy, some clinicians may proceed directly to thoracoscopy if the facilities for medical thoracoscopy are available. The procedure should be performed for diagnosis and possible talc poudrage [47].

The sensitivity of medical thoracoscopy was higher than that of cytology and closed pleural biopsy combined (96 versus 74%, pv0.001). Similar results have been reported by other investigators [89-92]. The reasons for false-negative thoracoscopy include insufficient and nonrepresentative biopsies that depend largely on the experience of the thoracoscopist [89, 92] and the presence of adhesions that prevent access to neoplastic tissue [87, 89].

The diagnostic yield of bronchoscopy is low in patients with undiagnosed pleural effusions and should not be undertaken routinely [93-95]. However, it is indicated when endobronchial lesions are suspected because of haemoptysis, atelectasis, or large effusions without contrala‐ teral mediastinal shift. Thoracotomy for diagnostic purposes is almost never indicated, because less invasive methods can provide diagnosis in up to 97% of cases [89, 96, 97].
