Pleural fluid
In about half of cases are always looking serosanguineous meet criteria for exudate, with glucose levels below 50 mg / dL and pH less than 7.2 in one third of patients. Pleural cytology is usually predominantly lymphocytic but has problems in distinguishing reactive mesothelial cells from malignant mesothelioma and metastatic adenocarcinoma, so sensitivity is low.

Closed blind pleural biopsy
It is done in this country using Abrams needle and profitability varies depending on the series, being generally low, around 20% although in our own series (unpublished data) is 80%.

Closed pleural biopsy with CT control
The return is higher when the biopsy is performed under CT control reaching 60% with one shot and up to 85% with repeat biopsies.

Surgical biopsy
Sometimes it is necessary to come to more invasive procedures for diagnosis should be a biopsy or by thoracoscopy or thoracotomy and in both cases the performance of the same 90%, with the former a lower relative risk of complications.

In the asymptomatic phase, diagnosis is done randomly, following a chest x-ray. Diagnostic imaging is divisive for the characteristic features, clearly visible on x-rays and the computed tomography. The radiological examination of the chest is essential for the precise diagnostic definition, and radiological aspects are variable in relation to the configuration assumed by the neoplastic process.

Localized forms (Fig. 2) show an area of intense opacities more or less, a polycyclic contours from whose context is different, the outer parietal and visceral pleura, mammellonature prominent. It ‘very often, after thoracentesis, detect radiographically lung parenchyma greatly retracted, veiled by an extensive opacity, the lung is unable to riespandersi, as the visceral pleura become rigid and inestensibile.Per confirming diagnostic pleural biopsy is needed, transparietale pleuroscopia or by histological examination supported by electron microscopy and by immunohistochemistry for the detection of CEA and the marker MPG 2. The needle biopsy transparietale is useful only if positive, otherwise we must resort to more invasive methods.

The fine needle aspiration of pleural fluid and subsequent exfoliative cytology hardly possible to make a diagnosis of mesothelioma for the high percentage of false negatives is due to the reduced tendency all’esfoliazione mesothelial cells, both false positives because of the difficulty in differentiating neoplastic mesothelial cells. Profit is the determination of hyaluronic acid, produced by the tumor stroma, in the pleural fluid, pathognomonic if less than 1 mg / ml.

The thoracoscopy is the best-invasive investigation; it reaches a positivity in more than 94% of patients, having the possibility to explore the whole pleural cavity and to obtain, under the supervision of view, large areas of tissue samples that appear pathological.

The thoracoscopy should be performed early in the presence of a payment to clear liquid, not dependent on causes inflammation, which is rebuilding quickly. The appearance is typical with mammellonature (a bunch of grapes). If the pleural cavity obliterated and appears to be impossible to introduce the thoracoscopy, pleural biopsy is necessary to resort to thoracotomy

Patients with mesothelioma have concentrations of mesothelin in pleural fluid from 7 to 12 times greater than patients with metastatic cancers or benign pleural effusions. Moreover, compared with cytology, pleural fluid mesothelin had better sensitivity, similar specificity and a greater negative predictive value.

Mesothelioma is a malignant attributed to asbestos exposure. The serum mesothelin is expressed by mesothelioma cells and released into the pleural fluid, making it more useful measurement pleuritic its measure serum.

These findings show that pleural fluid mesothelin is an invaluable aid to cytology in patients with undiagnosed pleural effusions. It is reproducible and not influenced by inflammatory joint effusions.