Malignant Pleura Effusion

7/30/2019 Malignant Pleura Effusion

1/3

MALIGNANT PLEURA EFFUSION

Pleural effusions are a significant public health problem. Diagnosis of over 1

million pleural effusions is estimated to occur yearly in the United States. Patients

with pleural effusions are frequently symptomatic with dyspnea and loss of

function. Treatment goals for these patients should focus on relief or elimination

of dyspnea, restoration of normal activity and function, minimization or

elimination of hospitalization, and efficient use of medical care resources.

Medical management, with treatment of the underlying cause, may be effective in

some transudates. For exudates, management may be more difficult. Malignant

pleural effusions (MPE; those effusions associated with primary, concurrent, or

distant neoplasms) may be more complex, with frequent recurrence. The arbitrary

view of requiring pleural symphysis, achieved by in-hospital drainage, with

pleurodesis achieved by sclerosis with chemical or other agents, may subject the

patient to a prolonged hospitalization or to other interventions that may

significantly reduce quality of life and remaining survival outside the hospital.

Pathophysiology

Pleural effusions occur between two membranes: the visceral (inner) layer of the

pleura attached to the lungs, and the parietal (outer) layer attached to the chest

wall. The pleural space normally is nonexistent and is lubricated by a slight

amount of pleural fluid (1020 cc) that provides lubrication between the pleura.

Fluid (sera) continuously moves from the parietal pleura through the pleural space

to be absorbed by the visceral pleura. The fluid is then drained into the lymphatic

system. The fluid in the pleural space is minimized by a balance of Starlingforces, oncotic pressure in the circulation, and negative pressure in the lymphatics

of the lungs.

In patients with primary malignancies, metastasis to the pleural space may cause

significant shifts or fluid imbalance from derangements in the Starling forces that

regulate the reabsorption of fluid within the pleural space. Movement of pleural

fluid across the pleural space may involve over 5 to 10 L/d, and derangements in


2/3

this movement may increase the normal amount of pleural fluid from 5 to 50 cc to

a more significant amount. Other disease processes may also significantly affect

the ability of the body to manage its intrapleural fluid. Pleural effusions may

occur in patients with:

increased capillary permeability caused by inflammation, infection, or pleuralmetastasis

increased hydrostatic pressure as results from congestive heart failure decreased oncotic pressure from hypoalbuminia increase in the normal negative pressure (more negative intrathoracic pressure)

secondary to atelectasis

impaired or decreased lymphatic drainage secondary to obstruction of thenormal lymphatic channels by tumor, radiation, or chemotherapyinduced

fibrosis

Although multiple mechanisms may contribute to the development of MPE, the

physician must consider the options available for diagnosis and to select the one

that is most easily applied. Small effusions may occur in association with an

intrathoracic neoplasm. If such effusions occur, the patient should have an

ultrasound-directed aspiration for diagnosis. In patients with primary lung cancer,

such small effusions must be evaluated. The presence of a cytologically positive

effusion suggests that the patient is unresectable for cure (clinical stage IIIB).

Patients with enormous pleural effusions have mediastinal shift, with impairment

of venous return to the heart. With much the same mechanism as tension

pneumothorax, this tension hydrothorax should be drained to prevent impending

cardiac and respiratory collapse.

Diagnosis

Etiology

Numerous benign, infectious, and malignant etiologies cause pleural effusions.

Twenty-five percent of all pleural effusions in a general hospital setting are

secondary to cancer. Patients with cancers frequently develop recurrent MPE

secondary to their disease. Thirty percent to 70% of all exudative effusions are


3/3

secondary to cancer. Increased levels of vascular endothelial growth factor are

present [6,7]. In patients with cancer, 50% to 60% of MPE are positive on first

thoracentesis. In 25% of patients with cancer and a recurrent pleural effusion,

malignant cells in the effusion may not be identified by pathologic examination.

Thoracoscopy is diagnostic in graether than 90% of patient with MPE. The

primary histologies for patient with MPE include non-small cell lung cancer,

breast cancer, lymphoma, or other malignancies such as ovarian cancer. Median

life expectancy ranges from 3 to 9 months, depending on the primary pathology.

History and Physical Examination

A though physical examination and careful history may reveal common causes of

pleura effusion. These causes include congestive failure, paraqpneumonic effusion

after or in association with pneumonia, primary or secondary malignancies of the

lung or pleural cavity, or pulmonal emboli. Patient may be diagnosed with MPE

by screening chest radiograph, as happen in patient with smaal asymptomatic

effusion, or they may have underlying symptoms of cough, dyspnea, or chest pain.

The physical examination demonstrates decreased breath sounds, dullnes to

percusion, or a pleural rub.

Documents

Malignant Pleura Effusion