CONGRESS ABSTRACT

Patients exposed to mediastinal radiotherapy are at long-term risk for cardiovascular and non-cardiovascular complications. Constrictive pericarditis is a recognized late effect; however, malignant pericardial infiltration represents a rare and potentially misleading alternative diagnosis. We report the case of a 52-year-old male with a history of childhood Hodgkin lymphoma treated with mediastinal radiotherapy, who over time developed thyroid disease requiring total thyroidectomy, post-actinic vasculopathy treated with carotid endarterectomy and an acute coronary syndrome in March 2023 with severe left ventricular dysfunction, successfully revascularized. At follow-up in September 2023, echocardiography showed improving left ventricular ejection fraction and a small, regressing, non-hemodynamically significant pericardial effusion. In December 2023, the patient was admitted for rapidly progressive dyspnea, peripheral edema and signs of right-sided heart failure. BNP was elevated (973 pg/mL). Chest CT revealed severe bilateral pleural effusions and circumferential pericardial fluid without mediastinal or pulmonary masses. The patient received anti-inflammatory and diuretic therapy, and underwent evacuative thoracentesis (pleural fluid cytology was non-diagnostic). He was then discharged home due to clinical improvement, with a planned short-term follow-up. He was soon re-admitted for atrial fibrillation with rapid ventricular response and further clinical deterioration. Serial echocardiograms documented rapid progression toward overt constrictive pericarditis with worsening biventricular dysfunction (LVEF 35–40%). A second CT confirmed persistent pleuro-pericardial effusions. Radiation-induced constrictive pericarditis was considered the most likely diagnosis, and the patient was referred to a tertiary cardiac center where he underwent pericardiectomy. Intraoperatively, extensive infiltrative mediastinal and pericardial masses were unexpectedly identified, precluding effective pericardiectomy. Histopathology revealed aggressive pleural mesothelioma with pericardial invasion. The patient died of refractory cardiocirculatory failure on postoperative day 2. In patients with a history of mediastinal radiotherapy, post-radiation constrictive pericarditis is the most likely diagnosis; however, the possibility of malignancy should not be excluded even if imaging and pleural fluid cytology are negative, particularly in cases of rapid clinical deterioration.