Colorectal non-Hodgkin lymphoma (NHL) is quite aggressive and rare, only constituting less than 1% of all cases of colorectal cancer. The pericardium is an extremely rare first site of metastasis. Cardiac tamponade can be a life-threatening initial presentation. We report a 55-year-old female who presented with severe shortness of breath, intermittent abdominal pain and altered bowel habits. She had low blood pressure with congested neck veins. Her echocardiogram showed pericardial and cardiac infiltration with tumour mass; a large pericardial effusion with signs of cardiac tamponade. There was no safe window for percutaneous drainage, and the patient was not physically fit for surgical drainage. A multidisciplinary approach was used to diagnose and manage the case involving a cardiologist, gastroenterologist, pathologist, radiologist and oncologist. CT scans of the whole body showed a large rectosigmoid mass infiltrating the uterus and adnexa. Flexible sigmoidoscopy showed a large bleeding mass at the rectosigmoid junction. The biopsy confirmed small cell NHL. Three cycles of chemotherapy were urgently commenced over a period of 5 weeks (1 cycle of CVP; 2 cycles of CHOP). The patient showed significant symptomatic improvement. A 5-week follow-up echocardiogram showed significant shrinkage of the pericardial tumour and only a small rim of pericardial effusion. The effusion did not recollect in her follow-up echocardiograms. A year later, she was referred to the palliative care team due to the further spreading of her lymphoma. In conclusion, colorectal small cell NHL may initially present as cardiac tamponade. Urgent initiation of chemotherapy can be a treatment option whenever a drainage procedure is unsafe.

Learning points: Colorectal small cell NHL is a quite rare malignancy that may present initially with pericardial metastasis.Cardiac tamponade secondary to colorectal NHL is a life-threatening presentation. It can be managed by timely chemotherapy alone whenever the usual drainage procedures are not safe.A multidisciplinary approach is a cornerstone in the management of unstable lymphoma patients. It helps the rapid diagnosis and initiation of appropriate chemotherapy.