Recurrent MALT lymphoma presenting as renal calyceal-pelvic rupture. What is the cause of this break?

Urinary collecting system rupture is an uncommon condition that usually occurs with symptoms of acute abdomen, secondary to peritoneal irritation by urine leaking. We report a case of a 49-year-old man admitted to our emergency department because of a worsening deep lower abdominal pain started 3 days before. The abdominal computed tomography revealed urine extravasation suggesting for urinoma. Because of patient pathological history of lymphoma, despite its apparent state of remission, he underwent a positron emission tomography - computed tomography with 18[F]-FDG and magnetic resonance in order to rule out a recurrence. Imaging supported the diagnostic hypothesis of a lymphatic recurrence that had compressed "ab-extrinseco" the urinary tract so much to break it. Based on our experience we can suggest that nontraumatic calyceal-pelvic rupture is an extremely rare manifestation of an onset of lymphoma.