The Challenge of Diagnosing Scirrhous Gastric Cancer by Endoscopic Biopsy: A Case Report.

Scirrhous gastric cancer, also known as linitis plastica, is a rare and aggressive subtype of gastric carcinoma that poses significant diagnostic challenges due to its submucosal infiltration and often normal-appearing mucosa. We report a case involving a 30-year-old Japanese woman who presented with a six-month history of epigastric pain and postprandial vomiting. Initial endoscopic examination revealed erythema and mucosal swelling, with limited antral distensibility and resistance during duodenal intubation. Despite 12 mucosal biopsies, histopathological examination revealed no evidence of malignancy. Given the strong clinical and endoscopic suspicion of scirrhous gastric cancer, additional deep sections and immunohistochemical staining were performed. These revealed scattered signet-ring cell carcinoma and poorly differentiated adenocarcinoma, with positive immunostaining for p53 and Ki67. The patient underwent total gastrectomy, and the diagnosis of scirrhous gastric cancer was confirmed on the resected specimen. This case highlights the importance of a high index of clinical suspicion, close collaboration between endoscopists and pathologists, and the utility of ancillary diagnostic tools, such as immunohistochemistry, in identifying subepithelial gastric malignancies that may be missed on conventional biopsy.