Case Report: Metastatic pancreatic ductal adenocarcinoma initially masked by multiple gastroduodenal ulcers with...

Pancreatic ductal adenocarcinoma (PDAC) is often diagnosed at an advanced stage because its early manifestations are nonspecific and may mimic benign gastrointestinal disorders. When multifocal gastroduodenal ulcers show benign histology and apparent healing after acid-suppressive therapy, the diagnostic impression may be misleading and delay recognition of an underlying malignancy.

A 69-year-old man presented with intermittent epigastric discomfort for 1 month. Upper gastrointestinal endoscopy revealed multiple ulcerative lesions involving the esophagus, stomach, and duodenum. Repeated biopsies showed only chronic inflammatory changes without dysplasia or malignancy. Helicobacter pylori testing was negative, and serum gastrin was within the normal range.

The patient was treated with high-dose vonoprazan (20 mg, bid, p.o.), and follow-up endoscopy demonstrated complete or near-complete healing of the ulcers. However, despite this favorable endoscopic response, the etiology of the extensive multifocal ulceration remained unexplained. Because this persistent diagnostic uncertainty was accompanied by ongoing symptoms and progressively rising carbohydrate antigen 19-9 (CA19-9) levels, further cross-sectional imaging was performed. Computed tomography and magnetic resonance imaging revealed a pancreatic tail mass with hepatic and peritoneal metastases. Laparoscopic biopsy of peritoneal nodules confirmed moderately differentiated adenocarcinoma, and immunohistochemical findings supported pancreatic ductal origin. A final diagnosis of metastatic PDAC was established.

Apparent endoscopic healing of multifocal gastroduodenal ulcers does not exclude an underlying systemic malignancy. When the cause of extensive ulcerative disease remains unresolved, especially in the setting of persistent symptoms and dynamic CA19-9 elevation, timely pancreatic imaging should be considered to avoid delayed diagnosis of PDAC.