Duodenal signet-ring carcinoma arising in pyloric gland adenoma with RN7SL1/MUC6 upregulation and mitochondrial dysregulation: A case report

Figure 1 Endoscopic and histologic findings of duodenal tumor. A: Polypoid lesion was found in the descending duodenum, presenting surface irregularity and hemorrhage; B and C: Low-power histology demonstrated closely packed pyloric gland-type tubules lined by a monolayer of cuboidal to low columnar epithelial cells with basally positioned round nuclei; D: High magnification examination revealed focal areas of signet ring cell carcinoma arising within the pyloric gland adenoma.

Figure 2 Immunohistochemical findings. The tumor cells showed strong positivity. A: Mucin-6; B: Mucin-5AC; C: Ki-67; D: P53.

Figure 3 Comprehensive molecular characterization of matched tumor and normal tissue by next-generation sequencing. Cluster heatmap of differentially expressed genes. Log10 (fragments per kilobase of transcript sequence per million mapped fragments + 1) values were used for hierarchical clustering. Genes with higher expression appear in yellow, whereas lower expression levels are shown in blue.

Figure 4 Kyoto Encyclopedia of Genes and Genomes pathway analysis. The result revealed significant enrichment in the tumor tissue for key processes such as viral protein-cytokine/receptor interaction, tumor necrosis factor signaling, and thyroid hormone synthesis.

Figure 5 Gene Ontology functional enrichment analysis. The result returns the Gene Ontology terms that are enriched among differentially expressed genes against the genomic background, and thus provides information on how the differentially expressed genes are related to certain biological functions. GO: Gene Ontology.