Pericardial Effusion as a Purported Manifestation of Graft-versus-Host Disease following Allogeneic Hematopoietic Cell Transplantation

•Large pericardial effusion (LPE) and tamponade are purported manifestations associated with atypical chronic graft-versus-host disease (GVHD) after allogeneic hematopoietic cell transplantation (alloHCT).•The median time from alloHCT to detection of LPE was 197 days (IQR, 40 to 378 days) in adult alloHCT recipients in our retrospective analysis.•LPE and tamponade necessitate urgent pericardiocentesis or pericardial window placement.•In a multivariable analysis, an HCT Comorbidity Index ≥3 and acute GVHD were risk factors for LPE.•LPE does not cause cardiac damage but results in inferior overall survival.