Pulmonary Artery Thromboembolism as a Complication of Essential Thrombocythemia.

Essential thrombocythemia (ET) is a chronic myeloproliferative neoplasm characterized by elevated platelet counts and an increased risk of thrombotic or hemorrhagic complications. It typically affects older individuals, with a higher prevalence in women, and is frequently associated with Janus kinase 2 (JAK2) mutations. While many cases follow an indolent course, major thrombotic events such as pulmonary embolism may occur. We report the case of a 72-year-old female patient with a known history of ET who presented with an acute onset of dyspnea and pleuritic chest pain. Computed tomography pulmonary angiography confirmed pulmonary artery thromboembolism. Laboratory tests revealed significant thrombocytosis. The patient was treated with anticoagulation and cytoreductive therapy, resulting in clinical improvement. This case highlights the importance of early recognition of thrombotic complications in patients with ET, even when they are receiving ongoing treatment.