Peritoneal lymphomatosis: a rare presentation of follicular lymphoma mimicking peritoneal carcinomatosis.

Patients presenting with ascites associated with peritoneal disease have a wide differential diagnosis including both malignant and non-malignant related causes. We present the unusual case of a patient, clinically deteriorating, whose malignant peritoneal disease was due to an underlying follicular lymphoma. An urgent staging CT scan followed by a peritoneal biopsy allowed the patient to start chemotherapy within days of acute presentation to the hospital. This case emphasises the importance of obtaining tissue diagnosis urgently in these patients to ensure that the correct treatment can be started in a timely manner.