P1704 An unusual mass in the right heart
Authors: Wojtkowska A , Brzozowski W , Prasal M , Lukasik S , Czekajska-Chehab E , Wysokinski A , Tomaszewski A 
Published: January 2020

Abstract
A 39 year old patient after removal of the uterus, the left oviduct and the right appendages due to Tu (massive fibroids). The histopathological examination revealed: leiomyomatosis intravascularis masiva (multifocal, intravenous smooth muscle cell hyperplasia without necrosis, cellular atypia and mitotic activity. Vascular invasion within the uterus, parametrium, mesovarium, perinodule tissues). The patient was admitted to the Gynaecology Clinic on the 9th postoperative day due to pain in the right lumbar region. The angio-CT of the thoracic, abdominal and pelvic cavities revealed a tumour/thrombus in the right internal iliac vein, common iliac vein and inferior vena cava (VCI). Then, the patient underwent transesophageal echocardiography (TEE) and transthoracic echocardiography (TTE) revealing an additional mass in the VCI entering the right atrium (RA), periodically passing through the tricuspid valve to the right ventricle (RV). The mass was of irregular shape, free-floating and did not obstruct the right ventricle inflow. Due to a suspicion of thrombus, an attempt at pharmacological treatment was initiated: initially LMWH at a therapeutic dose, followed by UFH iv. (controlled by APTT). Follow-up echocardiography: the image has not changed, the mass is still in the same location. The patient then underwent a surgical treatment: the pathological mass with a length of 35 cm was removed from VCI and RA with extracorporeal circulation. The histopathological examination confirmed: numerous foci of intravenous leiomyomatosis in the form of smooth muscle hyperplasia penetrating into the light of numerous vessels, mainly venous.

Discussion
Uterine fibroids are the most common benign tumours of the reproductive tract in premenopausal women, they are also the most common cause of hysterectomy. They are formed as a result of benign proliferation of myometrial smooth muscle cells. A special, though very rare, form is intravenous leiomyomatosis (IVL) - caused by abnormal growth of benign tumours, arising from smooth muscle, into venous vessels. Although histopathologically they are benign tumours, due to the possible invasion of large vessels they can be highly "aggressive" and extend into the heart chambers and pulmonary arteries (intracardiac leiomyomatosis - ICLM). Possible symptoms of ICLM: dyspnoea (30-37%), peripheral oedema (20-28%), chest pain (12-30%), palpitation (10-17%), fainting (11%). Approximately 13% of patients have no symptoms at all. In the differential diagnosis of masses in the right heart cavities, the following should be taken into account : thrombus, myxoma, metastases
of malignant neoplasms, in particular renal cancer, as well as: liver cancer, adrenal cancer, lymphoma, leiomyosarcoma.

Conclusion
IVL should be taken into account as a differential diagnosis in case of a free-floating mass in the right heart chambers, originating from the inferior vena cava, among premenopausal women with a history of hysterectomy.
Abstract P1704 Figure. mass in the right atrium