PMC9616105_01
Duodenal histopathological features of case 1 at diagnosis and during follow-up. (Ai) Duodenal biopsy at diagnosis showing severe villous atrophy, with normal intraepithelial lymphocyte count, as highlighted by CD3 staining (Aii) and increased eosinophilic count (Aiii). (Bi-iii) Duodenal biopsy performed 1 month after the suspension of pembrolizumab showing improvement of duodenal architecture with low-grade villous atrophy and resolution of eosinophilic mucosal infiltration.
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PMC9616105_01_DIC-2022-6-3_SCHIEPATTI_Figure1.jpg
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Duodenal biopsies confirmed severe VA, crypt hyperplasia and normal count of intraepithelial lymphocytes (IELs) but increased eosinophilic count (Figure 1Ai-iii). April 2021), pembrolizumab was stopped and the patient was started on chemotherapy (pemetrexed/cisplatin). Another gastroscopy with duodenal biopsies performed in June 2021, 1 month after pembrolizumab withdrawal, showed initial histological architectural improvement and reduction of eosinophilic count in the epithelium (Figure 1Bi-iii).
PMC9616105_02
Colonic (A, B) and duodenal (C, D) histopathological findings in patient 2. (A) H&E x200. Colonic biopsy showing acute colitis with crypt abscess and mild chronic inflammation. (B) H&E x400. Colonic biopsy showing prominent crypt cell apoptosis resembling acute graft versus host disease. (C) H&E x100. Duodenal biopsy showing total villus atrophy with acute and chronic inflammation. (D) H&E x200. Duodenal biopsy showing flat mucosa with cryptitis and mild chronic inflammation. Note absence of intraepithelial lymphocytes in the surface epithelium.
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PMC9616105_02_DIC-2022-6-3_SCHIEPATTI_Figure2.jpg
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Colonic biopsies showed crypt abscesses and neutrophilic inflammation (Figure 2A,B). Duodenal biopsies revealed severe VA with crypt hyperplasia, crypt abscesses (with presence of a few apoptotic bodies), and marked lymphoplasmacellular and neutrophilic infiltration of the lamina propria (Figure 2C,D).