case_images: PMC10359987_01
case_images: Mucinous adenocarcinoma with a goblet cell pattern, H&E x22.3.
case_images: fimmu-14-1160586-g001.jpg
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case_images: f1
case_images: Mucinous adenocarcinoma with a goblet cell pattern and widespread extracellular mucin secretion was detected ( Figure 1 ).
case_images: (A) MRI at the diagnosis. (B) PET/CT at the diagnosis.
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case_images: f2
case_images: Abdomen magnetic resonance imaging (MRI) showed a 14x5.5x5 cm conglomerate mass and implants extending to the root of the superior mesenteric vein and attaching to the duodenum with minimal ascites in the pelvis ( Figure 2A ). Positron emission tomography/computed tomography (PET/CT) scan revealed conglomerated lesion in the mesentery (SUVMax 23.5), wall thickening in the ascending colon (SUVMax: 26.1), and hypermetabolic areas in the abdomen thought to be due to the spread of the disease in the peritoneum ( Figure 2B ).
case_images: (A) MLH-1, IHC x10.0 (B) PMS-2, IHC x15.5 (C) MSI-H phenotype molecular analysis with PCR (D) MLH-1 methylation analysis.
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case_images: PMC10359987_01_fimmu-14-1160586-g003.jpg
case_images: f3
case_images: MSI panel from the primary tumor showed nuclear dot-like staining patterns for MLH1 ( Figure 3A ) and PMS2 ( Figure 3B ). Molecular analysis with PCR was performed due to suspicious staining patterns for MLH-1 and PMS-2. MSI-H phenotype ( Figure 3C ). MLH-1 methylation analysis was also performed; hypermethylation in the promoter region of the MLH-1 gene was detected ( Figure 3D ).
case_images: Timeline of the patient's management.
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case_images: f4
case_images: The timeline of the patient is summarized in  Figure 4 .