Retrospective study of pericardial fluid cytology to detect occult malignancy

Pericardial effusion may occur in patients with established cancer but may also represent the first manifestation of an occult malignancy. A retrospective study at the Victor Babes University of Medicine and Pharmacy (Timisoara, Romania) evaluated the diagnostic contribution of pericardial fluid cytology and pathological assessment to detect previously unrecognized malignancy. Among 209 patients hospitalized with pericardial disease between 2021 and 2025, 234 clinical episodes occurred. Pathological assessment was available in 95 of 234 episodes (40.6%), with neoplastic involvement identified in 21 of 95 episodes (22.1%). Neoplastic findings occurred in 13 of 33 (39.4%) evaluable episodes with known malignancy and 8 of 62 (12.9%) without a previous cancer diagnosis (OR 4.39; p=0.004). Conversely, 20 of 33 (60.6%) evaluable episodes in patients with known cancer showed no neoplastic involvement. In all eight patients without previously known malignancy, pericardial fluid cytology provided the first pathological evidence of cancer; six (75%) had findings suggestive of pulmonary origin. All presented with large effusions and hemodynamic compromise. The authors conclude that pericardial pathologic assessment may contribute to the detection of occult malignancy.