Intracardiac diffuse large B-cell lymphoma: an unexpected diagnosis.

Intracardiac lymphomas are exceedingly rare accounting for only 1% of all primary cardiac tumours. Historically, due to their insidious development and non-specific clinical presentation, the diagnosis has been challenging with most cases being confirmed on post-mortem examination. Our case report details the experience of a previously fit and active woman in her 60s who presented with gradual onset exertional dyspnoea. Through a series of multimodal imaging tools (including echocardiogram, cardiac MRI, CT and positron emission tomography-CT) and biopsy, we confirmed the diagnosis of intracardiac diffuse large B-cell lymphoma. Our patient was managed with chemotherapy and went on to demonstrate excellent radiological response with near-complete resolution of the intracardiac mass. Subjectively, our patient reported significant improvement in exercise tolerance within weeks of commencing treatment.