Higher sensitivity of pericardial fluid cytology than biopsy in malignant effusions with potential explanation of false-negative cytology: A multi-institutional analysis.

This study demonstrated diagnostic superiority of pericardial fluid cytology over biopsy in the evaluation of malignant pericardial effusions. We identified several limitations in fluid cytology causing false negatives. In the context of an underlying malignancy with pericardial effusion, pathologists should consider immunohistochemistry studies to aid on the diagnosis.