- Erdheim-Chester disease (ECD) is a rare inflammatory syndrome in which systemic infiltration of non-Langerhans cell histiocytes occurs in different sites. Both the etiology and pathophysiology of ECD are unknown, but CD68 positive CD 1a/S100 negative cells are characteristic. The presentation of ECD differs according to the involved organs. This case report describes a patient with ECD and the gastrointestinal manifestations and unique endoscopic appearance as seen in gastroscopy and colonoscopy with histological proof of histiocyte infiltration of the lamina propria. The clinical and endoscopic findings of this unique case, to our knowledge, were never described before, so were the features of the gastrointestinal involvement in this disease.