Pericardial fluid evaluation: Diagnostic yield and cytology-histology correlation

Pericardial effusion can be due to any etiology but may cause significant morbidity and mortality; however, malignant effusions are rare, and accurate and timely diagnosis is essential for appropriate further management. Data on the actual comparison of pericardial cytology and surgical specimens are limited, and this study was conducted to evaluate an institutional cohort and compare these two samples.

The institutional electronic database system was retrospectively searched between January 2019 and December 2023 for pericardial biopsies/surgical specimens (PSSs) and cytology.

A total of 202 surgical specimens of the pericardium were identified from patients with a median age of 67 years and a range of 18-97 years. Of these 202 cases, 190 specimens also underwent cytological evaluation, which included 153 cases that were negative for malignancy, nine cases that were indeterminate/atypical, and 28 cases that were positive for malignancy. Agreement between cytology and PSSs was reached in 172 cases, with 153 being benign and 19 being malignant. However, a cytology-histology discrepancy was found in 18 cases. Of these 18 cases, nine showed positive cytology but all had negative concurrent PSSs except for one with focal atypia, and the remaining nine were indeterminate/atypical on cytology. Eight of these nine indeterminate cases were negative on the PSS, whereas one atypical cytology case with low cellularity showed a positive PSS.

If atypical cases are excluded, cytology demonstrates a better diagnostic yield for detecting malignancy compared to surgical specimens (n = 28 cases vs. n = 20 cases, respectively).