(P259) RECURRENT PERICARDIAL EFFUSIONS AND INTRAPERICARDIAL THROMBI OF UNKNOWN ETIOLOGY

Case background: A previously healthy 76-year-old man presented with two-week history of pleuritic chest pain and shortness of breath. ECG demonstrated low voltage and electrical alternans. Echocardiogram demonstrated a large circumferential pericardial effusion with signs of increased intrapericardial pressures. He had a CRP of 148. A pericardial drain was inserted, draining 600mL of serosanguineous fluid. Fluid analysis was inflammatory but without infection, tuberculosis, or malignant cells. The patient was given the diagnosis of post-viral pericarditis and discharged on colchicine and NSAIDs.

Three months later, the patient presented again with progressive shortness of breath. Repeat echocardiogram demonstrated another pericardial effusion, but now with a 6.9cm intrapericardial echogenic mass compressing the right atrial free wall. CT redemonstrated this mass, which appeared like a thrombus. There were also large pleural effusions with exudative but otherwise benign fluid analyses. The patient underwent urgent sternotomy to surgically evacuate the mass. Pathology indicated fibrin-rich thrombus and pericardial biopsy showed non-specific reactive changes. The patient was discharged on postoperative day five.

Unfortunately, the patient presented again just three days later for shortness of breath. Repeat CT demonstrated another intrapericardial heterogeneous hematoma and thrombus, measuring 11cm this time. The development of the present intrapericardial thrombus must have occurred since the previous surgery. The cardiac surgeon who previously evacuated the clot noted that there was no residual clot at that time. In a repeat CT scan eleven days after the first, the size of the thrombus increased to 12.6cm. Workups from the respirology and rheumatology services were unremarkable. The case was discussed at rounds among multiple cardiologists and cardiac surgeons, who agreed that the imaging should be reassessed, and a repeat surgery might be required. The CT images were reviewed by dedicated cardiac imaging specialists, and it was conceded there was contrast pooling originating from the inferior aspect of the right atrium, possibly representing active bleeding.

A cardiac surgeon with prior experience in cardiac tumours took the patient to the operating room for re-sternotomy. After the evacuation of a massive intrapericardial clot, close inspection revealed a small heterogeneous mass that was actively bleeding at the right atrioventricular junction. Cardiac MRI was done at this point to further characterize the lesion, which raised suspicion for angiosarcoma, and biopsy eventually confirmed this unifying diagnosis. The patient was referred to a sarcoma oncologist for treatment. Unfortunately, he quickly deteriorated in functioning, and after a long five-month battle, he requested palliative care. He passed away comfortably ten days later.

Management Challenges: This case presented several diagnostic and management challenges due to the patient’s non-specific presentation in addition to the scarcity of cardiac tumours. Primary cardiac neoplasms are extremely rare, with a prior 40-year registry study estimating an incidence of all primary cardiac neoplasms of 0.008%. Among these, sarcomas reportedly represent about 65%, of which angiosarcomas specifically represent approximately 30%. As seen in this case, cardiac angiosarcomas present with very non-specific symptoms, such as dyspnea in 50-80% of patients, pericardial effusions in 29-56%, and chest pain in 10-39%. However, given the rare incidence and low suspicion for cardiac tumours, most patients have a delay in their diagnosis, and often patients are found to have metastatic disease by the time their diagnosis is confirmed. One study assessing similar sarcomas of the great vessels demonstrated the interval between first physician contact and the diagnosis of sarcoma to be 30-52 weeks.

Unfortunately, our patient’s interval of first healthcare contact to diagnosis was approximately five months. There were several challenges in the diagnosis beyond the non-specific symptoms. For one, the patient had undergone prior cardiac surgery, which at that time did not reveal an obvious neoplasm or etiology of the recurrent pericardial effusions and thrombi. Given the recent surgical exploration, there was hesitancy to pursue repeat surgical exploration. Similarly, despite the numerous fluid analyses and cytologies that were sent, as well as the biopsies taken during the initial surgical exploration, all pathological work-up was negative and non-diagnostic. Finally, there was uncertainty in which imaging methods to pursue, given it was unclear if the etiology was structural, vascular, neoplastic or infectious. These diagnostic challenges presented significant barriers before even considering management.

Notwithstanding these challenges, there were areas for prompter diagnosis that became clearer in retrospect. First, the initial serosanguinous pericardiocentesis should have raised early suspicion of a sinister underlying process, as these are often associated with malignancy and other serious conditions such as tuberculosis, ischemia, or dissection. Further, a closer initial review of the patient’s CT scans, with careful attention for contrast-pooling and extravasation, may have also expedited diagnosis. Similarly, this patient’s cardiac MRI was late in the course, and earlier dedicated imaging with cardiac MRI or PET would have differentiated an underlying tumour sooner. Finally, prompt referral to a cardiac surgeon with expertise in cardiac tumours is important, as given the rarity of such tumours, the first surgeon in this case was not familiar with the identification of these lesions.

Overall, we present a case of recurrent pericardial effusions and thrombi with several diagnostic and management challenges, that was eventually diagnosed as angiosarcoma. Through the challenges faced in our patient’s course, we hope to provide recommendations for physicians facing similar challenges in the future. In particular, in patients presenting with serosanguinous effusions, we recommend a thorough assessment to rule out more sinister etiologies before labelling an effusion as idiopathic. A high index of suspicion should remain even when fluid and biopsy analyses are non-diagnostic. Further, we recommend that imaging interpreters seek for cardiac tumours in cases of recurrent effusions or thrombi of unknown etiology by assessing for contrast-pooling and extravasation. We also suggest early consideration of cardiac MRI or PET in such cases to assess for tumours. Finally, in cases suspicious for malignancy, we suggest early referral to dedicated cardiac imaging specialists and cardiac surgeons with prior experience in cardiac tumours.