RT Journal Article SR Electronic T1 Pancreaticoduodenal artery aneurysm associated with polyarteritis nodosa presenting as massive upper gastrointestinal bleeding JF BMJ Case Reports JO BMJ Case Reports FD BMJ Publishing Group Ltd SP e247359 DO 10.1136/bcr-2021-247359 VO 14 IS 11 A1 Juan Carlos Reyes Abon A1 Marc Paul Jose Lopez A1 A'Ericson Berberabe A1 Kenan Jared Cinco YR 2021 UL http://casereports.bmj.com/content/14/11/e247359.abstract AB The pancreaticoduodenal arteries are rare sites for true aneurysm formation, but these may develop in association with occlusion of the coeliac circulation, degenerative conditions or inflammatory vascular disorders. These have a high risk of rupture regardless of size or other factors. One identified cause is polyarteritis nodosa (PAN), which is an autoimmune necrotising vascular condition that affects small-sized and medium-sized arteries. We report a case of a 40-year-old man with massive gastrointestinal tract bleeding from a ruptured pancreaticoduodenal artery aneurysm secondary to PAN. This was managed with emergent open aneurysm ligation followed by high-dose corticosteroids and cyclophosphamide pulse therapy. Only three other cases of PAN-associated pancreaticoduodenal artery aneurysms have been reported in the literature.