Breast cancer is the most common cause of malignant pleural effusions in women. They are more commonly seen ipsilateral to the primary tumor, suggesting that the effusion sometimes arises via direct extension through the chest wall or through involvement of internal mammary lymph nodes. While 80 percent of malignant pleural effusions arise in the presence of other sites of metastatic involvement,30 they are usually symptomatic and require specific treatment.
In a previously untreated patient with newly metastatic breast cancer, an attempt may be made to relieve the malignant pleural effusion with therapeutic thoracentesis and initiation of systemic chemotherapy or hormonal therapy. In this setting, a positive response to systemic therapy is likely and may be sufficiently rapid to prevent reaccumulation of fluid. In patients with previously treated metastatic disease, however, the likelihood of objective response to any systemic therapy is certainly < 50 percent; definitive treatment with chest tube drainage and sclerosis is recommended. Failure to adequately manage a malignant pleural effusion can result in a trapped lung, with permanent dyspnea, cough, and pain.
The purpose of chest tube placement and suction drainage is to empty the pleural space to permit approximation of the visceral and parietal pleura. When chest tube output is minimal, any of a variety of topical irritants is instilled and the patient repositioned every 15 minutes for 2 hours to distribute the irritant throughout the pleural space. The goal is to create adhesions between the irritated visceral and parietal pleura to prevent subsequent massive reaccumulation of fluid with atelectasis. There have been a variety of agents employed, including talc slurry, tetracycline, bleomycin, and other chemotherapeutic agents. In a randomized trial comparing the first three agents, an insufficient number of patients was accrued; in the absence of a direct comparison, talc appears to have the highest success rate.31
Pericardial effusions are not uncommon and may eventually occur in up to 25 percent of all women with metastatic breast cancer.32 The presenting complaint is typically exertional dyspnea. Chest radiography and resting arterial oxygen saturation may both be normal, requiring this diagnosis to be specifically considered in the dyspneic patient.33 As pericardial effusions occur not infrequently in conjunction with malignant pleural effusions but go unrecognized on chest radiography, pericardial effusions should also be considered whenever pleural effusions are diagnosed. Physical exam may show tachycardia, an absent precordial cardiac impulse, a pericardial friction rub, atrial fibrillation, and pulsus paradoxus. Electrocardiogram will show decreased voltages in the precordial leads. Definitive diagnosis of pericardial effusion requires echocardiography, which may also demonstrate cardiac tamponade with diastolic collapse of the right atrium and ventricle.34
Patients with symptomatic or hemodynami-cally significant pericardial effusions should undergo immediate drainage. Immediate catheter drainage can prevent cardiovascular collapse in patients with tamponade but does not provide definitive treatment. The creation of a subxiphoid pericardial window is a relatively simple surgical solution with a high success rate.35 Open thoracotomy with pericardial stripping has a much higher morbidity and is required only for rare patients with constrictive pericarditis.
Malignant ascites can develop as a manifestation of peritoneal metastases, occurring more frequently in patients with infiltrating lobular carcinoma. Symptoms include bloating, distension, early satiety, and shortness of breath. Both ultrasound and CT scan can demonstrate ascites, with the latter also revealing peritoneal studding or omental thickening in some patients. While the most satisfactory control of malignant ascites is achieved with effective systemic therapy, this is often not possible where ascites occurs as a late complication of advanced disease. Therapeutic paracentesis may provide transient relief of symptoms. Repeated drainage of several liters of ascitic fluid may result in hypotension or hypoalbu-
minemia, however. Diuretics are seldom helpful in managing malignant ascites.
Was this article helpful?