LAUSR

Background Primary malignant tumors of the heart are rare. Although preoperative histological diagnosis is difficult, it has paramount value in therapeutic strategy development and prognostic estimation. Herein, we reported 2 cases of intracardiac tumors. Cases presentation Both patients presented to the hospital with heart-related symptoms. Echocardiography showed massive masses in the atrium and positron emission tomography–computed tomography (PET/CT) revealed hypermetabolism and invasiveness. One patient cannot take surgery due to extensive metastasis and poor condition. The other patient was primarily diagnosed with lymphoma, and surgery was not recommended. They successfully underwent intravenous atrial biopsy, and histological samples confirmed intimal sarcoma and diffuse large B cell lymphoma. Based on immunohistochemical and molecular assessments, targeted chemotherapy was administered, resulting in clinical and imaging remission at discharge. Conclusions Percutaneous intravenous catheter biopsy as a safe invasive test provides an accurate pathological diagnosis after imaging evaluation, and offers a therapeutic direction. Nonmalignant masses and some chemo-radiosensitive malignant tumors in the atrium could have good prognosis after targeted therapy.