Figure 1.

Clinical progression and histological features of immunotherapy-associated gastritis

(A) Scheme of the patient clinical progression. CT, computer tomography subjects; yo, years old.

(B) Representative hematoxylin and eosin (H&E) regions revealed diffusely eroded mucosa with variable infiltration of crypt epithelium by neutrophils (yellow arrows) or lymphocytes (white arrows) (top panels). Foci of more significant epithelial injury showing ulceration (black asterisks) with crypt abscesses (black arrows), crypt withering/degeneration (yellow asterisks), and crypt dropout were noted (bottom panels). The lamina propria across all biopsies was expanded by mixed inflammatory infiltrates consisting of abundant lymphocytes, scattered plasma cells and neutrophils, and few eosinophils and mast cells.

(C) Scheme of the special stains carried out to exclude infectious agents, including Grocott’s methenamine silver (GMS) to exclude fungal organisms, and further immunohistochemical stains that excluded cytomegalovirus, herpes simplex virus, Epstein-Barr virus, and Helicobacter pylori.