Unexpected Right Atrial Mass in a Young Woman: An Unpleasant Surprise

Abstract Introduction Atrial masses represent a diagnostic challenge as the differential diagnosis includes a broad spectrum of formations. Thrombus is the most common form of non–neoplastic mass, whereas cardiac tumors are rare. We reported a case of a young woman with high–grade endometrial stromal sarcoma, complicated by cardiac metastatic dissemination. Case Report A previously healthy woman of 36–years old, without medical history, underwent abdominal ultrasound due to frequent menorrhea. As suspicious uterine formation was observed, an abdomen magnetic resonance (MRI) was performed, showing a large formation located in correspondence of uterine corpus and fundus. Indeed, she underwent hysterectomy plus bilateral salpingectomy, and the subsequent histological examination revealed a high–grade endometrial stromal sarcoma (ESS). Consequently, the patient was hospitalized to undergo a total body computed tomography (CT) for tumor staging and to start chemotherapy (potential cardio–toxic). A trans–thoracic echocardiogram (TTE) showed normal function of LV, without valvulopathies. However, in correspondence of right atrium (RA) roof, a large, rounded mass, hypomobile and iso/hyper–echogenic, without extension into Superior Vena Cava, was detected. The total body CT confirmed the presence of a hypodense mass in the RA, and secondary lesions within left large pectoral muscle and right inferior lung lobe were founded. Thus, a Cardiac MRI was performed, showing a solid formation, with lobulated margins and oval morphology, at the level of the posterior wall of the RA, of about 2.5 x 1.8 cm and with longitudinal extension of about 3 cm, hypomobile and with a wide implant base. The lesion appeared heterogeneously hypo–isointense in T1–weighted images and hyperintense in T2–weighted images; in Delayed–Enhancement acquisitions, the formation resulted hyper–intense, more evidently in long–inversion recovery sequences. Indeed, considering clinical condition, right atrial location and morphological features, the diagnosis of secondary lesion of the ESS was entertained. First–line chemotherapy regimen was started. After 6 months follow–up the patients remained asymptomatic; at TTE, the cardiac mass resulted unchanged. Unfortunately, after 13 months, the patient died. Conclusion A multimodality imaging approach to the evaluation of atrial masses is crucial for obtaining a non–invasive evaluation to provide the appropriate therapeutic approach.