Cardiac tamponade associated with primary myelofibrosis: a case report.

Background: Cardiac tamponade is a life-threatening condition that occurs when an abnormal amount of fluid accumulates in the pericardial sac and impedes the cardiac filling process. Although extremely rare, haematological diseases have the potential to trigger an extramedullary haematopoiesis (EMH) process within the pericardium, resulting in a substantial build-up of pericardial effusion. Case summary: We present the case of a 29-year-old male previously diagnosed with primary myelofibrosis (PMF), who presented to the emergency unit with cardiac tamponade. An emergent pericardiocentesis procedure was performed, successfully evacuating 850 mL of haemorrhagic fluid. Over the course of 3 days, a total of 1.5 L of haemorrhagic effusion were drained from the pericardial space. Analysis of the pericardial fluid revealed evidence of haematopoietic activity, suggesting a potential association with the EMH process occurring within the pericardium. Following a 7-day hospitalization, the patient was discharged in stable condition but later experienced the development of constrictive pericarditis. Discussion: Haemorrhagic pericardial effusion is a rare occurrence. The majority of cases stems from complications of medical procedures (iatrogenic), malignancies, or side effects of antiplatelet/anticoagulant medications. In patients with PMF, the impaired haematopoietic ability caused by the fibrotic process in the bone marrow compels the body to produce blood components elsewhere, a phenomenon known as EMH. On very rare occasions, EMH can develop in the pericardial space, potentially leading to life-threatening cardiac tamponade. Our patient was successfully managed through pericardial fluid evacuation and drainage but later developed constrictive pericarditis.