Primary Pericardial Sarcoma with Right Atrial Invasionand Multiple Bilateral Pulmonary Metastases in a Patient withHereditary Nonpolyposis Colorectal Cancer

Primary tumours originating from the pericardium are extremely rare. Previous studies have reported that these tumours accountfor only 6.7–12.8% of all mediastinal tumours with an overall prevalence of 0.001% to 0.007%. The majority of these tumoursare benign lipomas or pericardial cysts. The most common pericardial malignancy is mesothelioma. Sarcomas are soft-tissuemesenchymal malignancies originating from various parts of the body but are extremely rare in this area. We report a case of a 52-year-old female who was diagnosed with a primary sarcoma with rhabdoid differentiation originating from the pericardium. Thepatient presented to her GP with a four-week history of progressive dyspnea and chest pain on exertion. Chest X-Ray demonstrateda prominent pericardial effusion and suspicious chest and pericardial lesions. Biopsies of the effusion and primary tumour identifiedon FDG/PET scans revealed the diagnosis of primary undifferentiated sarcoma. On thoracotomy, it was noted that the tumour hadinvaded the right atrium; therefore, pericardial window was aborted and a drain inserted instead. The patient was then startedon chemotherapy; however, progression soon occurred and the patient died within 4 months, suggesting there is urgent need forefficacious treatments for sarcomatous lesions