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For further information, see CMDT Part 39-26: Malignant Effusions
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Half of undiagnosed effusions in patients not known to have cancer are malignant
Malignant effusions occur in pleural, pericardial, and peritoneal spaces
Caused by direct neoplastic involvement of serous surface or obstruction of lymphatic drainage
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Patients with pleural and pericardial effusions complain of shortness of breath and orthopnea
Patients with ascites complain of abdominal distention and discomfort
Cardiac tamponade causing pressure equalization in the chambers impairs both filling and cardiac output can be life-threatening; signs of tamponade include
Tachycardia
Muffled heart sounds
Pulsus paradoxus
Hypotension
Signs of pleural effusions include decreased breath sounds, egophony, and percussion dullness
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Presence of malignant cells in either the cytology or cell block specimen confirms malignancy as cause of effusion
The presence of effusions can be confirmed with radiographic studies or ultrasonography
Differential diagnosis
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