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. Author manuscript; available in PMC: 2024 Jan 1.
Published in final edited form as: Gastroenterology. 2022 Oct 6;164(1):117–133.e7. doi: 10.1053/j.gastro.2022.09.028

Figure 4.

Figure 4.

Representative examples of diagnostic surgical pathology for IPMNs that had preoperative PancreaSeq testing. (A) A branch-duct IPMN that was resected because of the presence of a mural nodule (white arrowhead) detected on preoperative imaging. (B) The mural nodule corresponded to collapsed papillary fronds and (C) microscopically, correlated with low-grade dysplasia. Preoperative PancreaSeq testing detected the presence of KRAS and GNAS mutations, but an absence of TP53, SMAD4, CTNNB1, with mTOR gene alterations. (D) A branch-duct IPMN (white arrowhead) with focal ductal dilation and otherwise no concerning preoperative clinical, imaging, or preoperative pathologic findings. Preoperative PancreaSeq testing identified mutations in KRAS and GNAS, and LOH for PTEN and TP53. (E and F) Diagnostic surgical pathology revealed the presence of high-grade dysplasia. (G) A branch-duct IPMN (white arrowhead) with focal ductal dilatation and otherwise no concerning preoperative clinical, imaging, or preoperative pathologic findings. PancreaSeq testing detected a KRAS mutation and a low-level TP53 mutation. Although the submitting surgical pathology report documented the presence of an IPMN with low-grade dysplasia, a (H) focal area of cytologic atypia was identified and (I) corresponded to aberrant nuclear p53 expression. (J) A 3.0-cm branch-duct IPMN (white arrowhead) with otherwise no concerning preoperative clinical, imaging, or preoperative pathologic findings; however, PancreaSeq testing identified a KRAS mutation and SMAD4 LOH. (K) Although histologically consistent with an IPMN with low-grade dysplasia, (L) diffuse loss of Smad4 expression was seen throughout the IPMN. The mTOR genes include PIK3CA and PTEN. (B) Hematoxylin and eosin stain, magnification 20×. (C) Hematoxylin and eosin stain, magnification 200×. (E) Hematoxylin and eosin stain, magnification 20×. (F) Hematoxylin and eosin stain, magnification 200×. (H) Hematoxylin and eosin stain, magnification 200×. (I) p53 immunolabeling, magnification 200×. (K) Hematoxylin and eosin stain, magnification 200×. (L) SMAD4 immunolabeling, magnification 200×.