A Case of Granulomatosis with Polyangiitis Predominantly Presenting with Gastrointestinal Involvement: A Diagnosis Made by a Colonic Biopsy and Successful Endoscopic Balloon Dilation for Cicatricial Stricture.

A 73-year-old woman predominantly presented with diarrhea, accompanied by abdominal pain and hematochezia. Colonoscopy revealed multiple colonic ulcers with skip lesions, and a biopsy displayed small-vessel vasculitis, leading to a diagnosis of granulomatosis with polyangiitis (GPA). Corticosteroid therapy improved the ulcers; however, cicatricial stricture developed at the splenic flexure, which was successfully managed with endoscopic balloon dilation (EBD). This rare case of GPA, predominantly presenting with gastrointestinal symptoms, underscores the significance of considering vasculitis in unexplained gastrointestinal lesions and demonstrates the effectiveness of EBD as a minimally invasive treatment for cicatricial stricture secondary to GPA.