Evidence map›Paper›PMID 41800032›Full record

ArticleFrontiers in oncology2026

A case report and literature review of duodenal adenocarcinoma with complete loss of mismatch repair proteins.

Jie Ao, Xiangfeng Zhu, Yuan Zhao, Mimi Zhao, Yi Luo, Qiushi Wang

Abstract readCase Reports
In one paragraph

Article in Frontiers in oncology, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

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Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

1 citing paper in PubMed.

  1. Review
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

6 authors.

Jie Ao *Department of Pathology, Daping Hospital, Army Medical University, Chongqing, China.
Xiangfeng Zhu *Department of Pathology, Daping Hospital, Army Medical University, Chongqing, China.
Yuan ZhaoDepartment of Pathology, Daping Hospital, Army Medical University, Chongqing, China.
Mimi ZhaoDepartment of Radiology, Daping Hospital, Army Medical University, Chongqing, China.
Yi LuoDepartment of Nuclear Medicine, Daping Hospital, Army Medical University, Chongqing, China.
Qiushi WangDepartment of Pathology, Daping Hospital, Army Medical University, Chongqing, China.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Background: Deficient mismatch repair (dMMR)/microsatellite instability-high (MSI-H) phenotype holds significant prognostic and therapeutic implications in gastrointestinal cancers. While typically characterized by loss of specific MMR protein pairs, the concomitant loss of all four MMR proteins (MLH1, PMS2, MSH2, MSH6) is scarcely documented, with molecularly confirmed cases being exceptionally rare. Case presentation: We presented a case of duodenal adenocarcinoma whose contrast-enhanced 64-row CT and PET/CT demonstrated characteristic features highly suspicious for malignancy. Subsequently, the patient underwent duodenal resection. Histopathology showed moderately differentiated adenocarcinoma invading the subserosa and immunohistochemical staining revealed MLH1, PMS2, MSH2 and MSH6 were completely lost in tumor cells. Molecular profiling confirmed MSI-H status, high tumor mutational burden (TMB-H), MLH1 promoter hypermethylation and somatic mutations in MSH2 and MSH6 genes, but without pathogenic germline variants. Conclusion: We represent a molecularly validated case of dMMR duodenal adenocarcinoma, suggesting a somatic molecular pathogenesis distinct from classic intestinal cancer. The findings highlight the critical importance of comprehensive molecular characterization in rare tumors, as accurate identification of these phenotypes are important for optimal treatment selection, particularly immune checkpoint inhibitor therapies for gastrointestinal malignancies.

Indexed as

duodenal adenocarcinomahigh microsatellite instabilitymismatch repair deficiencysomatic mutationtumor mutational burden

Identifiers

PMID41800032
PMCPMC12960096

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