Diagnosis of malignant pericarditis: a single centre experience.

BACKGROUND: Malignancy is the most common cause of effusive pericarditis with a haemodynamically significant amount of pericardial fluid. Early diagnosis and management of malignant pericarditis may significantly improve outcomes. AIM: To evaluate retrospectively the rate and clinical presentation of malignant pericarditis among patients undergoing invasive treatment, with a view to identification of optimal diagnostic modalities to distinguish this group among other patients.
METHODS: We studied 191 patients (100 men and 91 women, median age 57 years, range 19-88 years) with effusive pericarditis who underwent invasive treatment in the National Institute of Tuberculosis and Lung Diseases in Warsaw in 1982- -2008 due to a significant amount of pericardial fluid and/or echocardiographic evidence of cardiac tamponade. Pericardiocentesis was performed in 93 cases, pericardioscopy in 61 cases, and substernal pericardiotomy in 37 cases. Pericardial fluid was sent for examination in all patients, and a pericardial specimen was obtained in 96 patients. The patients were divided into 3 groups: Group 1 included patients with malignant pericarditis (malignant cells found in the cytological examination of the pericardial fluid and/or neoplastic infiltration in the histological examination of the pericardial specimen), Group 2 included patients with probable malignant pericarditis (pericardial fluid without malignant cells with histologically confirmed malignancy at some other location), and Group 3 included patients with non-malignant pericarditis (negative cytological examination of pericardial fluid and histological examination of the pericardial specimen, with no evidence of malignancy during hospitalization and one-year follow-up).
RESULTS: Malignancy was found in 111 (58%) of 191 patients, including 66 (35%) patients with definite malignant pericarditis and 45 (23%) patients with probable malignant pericarditis. Lung cancer, including adenocarcinoma, was the most common type of malignancy, present in 44 (67%) patients. Non-malignant pericarditis was found in 80 (42%) patients. Among patients with the diagnosis of malignancy (Groups 1 and 2), a positive result of the cytological examination of the pericardial fluid was obtained in 52 cases (sensitivity of 46%). Among patients without malignancy, a negative result of the cytological examination of the pericardial fluid was obtained in all 80 cases (specificity of 100%). Malignant infiltration was found in 20 of 44 patients with the diagnosis of malignancy (sensitivity of 46%) and in none among 52 patients without malignancy (specificity of 100%). Compared to patients with non-malignant pericarditis, patients with malignant pericarditis significantly more commonly presented with tachycardia of >100 bpm in a resting electrocardiogram (ECG) (in 77% of patients with malignant pericarditis vs. 43% of patients with non-malignant pericarditis, p = 0.01), low QRS amplitude (52% vs. 34%, respectively, p = 0.03), electrical alternans (19% vs. 3%, respectively, p = 0.001), echocardiographic evidence of cardiac tamponade (67% vs. 34%, respectively, p = 0.0001), enlarged mediastinal lymph nodes by chest computed tomography (CT) (90% vs. 29%, respectively, p <0.00001), pericardial thickness >8 mm by chest CT (62% vs. 16%, respectively, p <0.0001), and bloody pericardial effusion (94% vs. 43%, respectively, p <0.0001). Levels of carcinoembryonic antigen (CEA) and cytokeratin fragment-19 (CYFRA 21-1) in the pericardial fluid were higher in patients with malignant pericarditis compared to patients with non-malignant pericarditis, with median values of 40.8 ng/mL vs. 0.9 ng/mL, p <0.0001, and 162.85 ng/mL vs. 13.35 ng/mL, p <0.0001, respectively.
CONCLUSIONS: 1. Malignancy was found in 58% of patients undergoing invasive treatment due to large pericardial effusion. 2. Cytological examination of the pericardial fluid and histological examination of a pericardial specimen showed high specificity (100%) but low sensitivity (46%) in the diagnosis of malignant pericarditis. 3. The most important predictors of malignant pericarditis included tachycardia of >100 bpm as revealed by the physical examination and ECG, echocardiographic evidence of cardiac tamponade, presence of enlarged mediastinal lymph nodes (>1 cm) and thickened pericardium (>8 mm) by chest CT, bloody pericardial effusion, and elevated levels of CEA (>5 ng/mL) and CYFRA 21-1 (>50 ng/mL) in the pericardial fluid.