Pancreatic mixed acinar-neuroendocrine carcinoma with intraductal growth: A case report with radiologic-pathologic correlations.

Pancreatic mixed acinar-neuroendocrine carcinomas are rare malignant tumors of the pancreas. They are composed histologically of both acinar and neuroendocrine cells. The pancreatic duct is known to be an important site of tumor growth for acinar cell carcinomas, neuroendocrine tumors, and intraductal tubulopapillary neoplasms. To the best of our knowledge, there has been only 1 report of a mixed acinar-neuroendocrine carcinoma growing into the pancreatic duct and no reports detailing imaging findings with this tumor. We here report a 69-year-old man who presented with worsening glycemic control. Multiphase contrast-enhanced computed tomography and magnetic resonance imaging revealed a well-circumscribed mass with poor contrast enhancement in the pancreatic tail region of the pancreatic duct. The intraductal mass showed diffusion restriction on magnetic resonance imaging. These imaging findings are consistent with the expansive, smooth-surfaced polypoid tumor of low vascularity and high cellularity that was diagnosed pathologically. Mixed acinar-neuroendocrine carcinomas should be included in the differential diagnosis of intraductal tumors of the pancreas with poor contrast enhancement and diffusion restriction.

Hepatocyte- or macrophage-specific SREBP-1a deficiency in mice exacerbates methionine- and choline-deficient diet-induced nonalcoholic fatty liver disease.

Sterol regulatory element-binding proteins (SREBPs) are master transcription factors for lipid synthesis, and SREBP-1 is important for fatty acid and triglyceride synthesis. SREBP-1 has two isoforms, SREBP-1a and SREBP-1c, which are splicing variants transcribed from the Srebf1 gene. Although SREBP-1a exhibits stronger transcriptional activity than SREBP-1c, hepatic SREBP-1c is considered more physiologically important. We generated SREBP-1a flox mice using the CRISPR/Cas9 system and hepatocyte- and macrophage-specific SREBP-1a knockout (KO) mice (LKO, liver-knockout; and mΦKO, macrophage-knockout). There were no significant differences among all the mouse genotypes upon feeding with a normal diet. However, feeding with a methionine- and choline-deficient (MCD) diet resulted in exacerbated liver injury in both KO mice. In LKO mice, fatty liver was unexpectedly exacerbated, leading to macrophage infiltration and inflammation. In contrast, in mΦKO mice, the fatty liver state was similar to that in flox mice, but the polarity of the macrophages in the liver was transformed into a proinflammatory M1 subtype, resulting in the exacerbation of inflammation. Taken together, we found that SREBP-1a does not contribute to hepatic lipogenesis, but in either hepatocytes or macrophages distinctly controls the onset of pathological conditions in MCD diet-induced hepatitis.NEW & NOTEWORTHY Hepatocyte- and macrophage-specific SREBP-1a knockout mice were generated for the first time. This study reveals that SREBP-1a does not contribute to hepatic lipogenesis, but in either hepatocytes or macrophages distinctly controls the onset of pathological conditions in methionine- and choline-deficient diet-induced hepatitis.

Wogonin, a Compound in Scutellaria baicalensis, Activates ATF4-FGF21 Signaling in Mouse Hepatocyte AML12 Cells.

Fibroblast growth factor 21 (FGF21), which is mainly synthesized and secreted by the liver, plays a crucial role in systemic glucose and lipid metabolism, ameliorating metabolic diseases. In this study, we screened the WAKANYAKU library derived from medicinal herbs to identify compounds that can activate Fgf21 expression in mouse hepatocyte AML12 cells. We identified Scutellaria baicalensis root extract and one of its components, wogonin, as an activator of Fgf21 expression. Wogonin also enhanced the expression of activating transcription factor 4 (ATF4) by a mechanism other than ER stress. Knockdown of ATF4 by siRNA suppressed wogonin-induced Fgf21 expression, highlighting its essential role in wogonin's mode of action. Thus, our results indicate that wogonin would be a strong candidate for a therapeutic to improve metabolic diseases by enhancing hepatic FGF21 production.

"Honeycomb" appearance in large-duct type pancreatic ductal adenocarcinoma: Case report with radiologic-pathologic correlation.

Large-duct type pancreatic ductal adenocarcinoma (PDA) is a rare morphologic variant forming large duct elements. This case report, to our knowledge, is the first report of a large-duct type PDA with a "honeycomb" appearance resembling a serous cystic neoplasm (SCN) on CT and MRI. The patient is an 82-year-old woman who presented with upper abdominal pain. Dynamic contrast-enhanced CT revealed a multilocular cyst with honeycomb loculi, in which the cyst walls showed gradual enhancement. On T2-weighted MRI, the mass displayed inhomogeneous hyperintensity characterized by a honeycomb appearance with irregular and thick hypointense cyst walls. The patient underwent distal pancreatectomy; histopathological diagnosis was large-duct type PDA. Although the imaging features of large-duct type PDA may resemble those of SCN, this distinction between PDA and SCN is important because the treatment options are very different.

Retrospective evaluation of venous phase contrast-enhanced computed tomography images in patients who developed pancreatic adenocarcinomas after treatment for nonpancreatic primary cancer.

OBJECTIVES: To clarify venous phase contrast-enhanced CT findings in early pancreatic adenocarcinomas by retrospectively evaluating CT images of pancreatic adenocarcinomas that developed during follow-up after treatment for non-pancreatic cancers. METHODS: The study cohort comprised six patients who developed pancreatic adenocarcinomas between April 2005 and April 2020 during follow-up after treatment for non-pancreatic primary cancers. Two radiologists retrospectively evaluated CT images and reached consensus on previously reported CT findings that were suggestive of small pancreatic adenocarcinomas; namely pancreatic duct interruption and dilatation, pancreatic parenchymal atrophy, focal hypoattenuated areas, and appearance of cystic lesions. Time intervals between the first CT with these suggestive findings and the latest pre-operative CT were recorded. Doubling times were calculated in patients with hypoattenuated areas on initial CT scans. RESULTS: Small (<10 mm) focal hypoattenuated areas with (n = 2) or without rim enhancement (n = 1) were identified on initial CT images of three patients. Pancreatic duct interruption and dilatation, pancreatic parenchymal atrophy, and cystic lesion were identified in two, one and one patient, respectively. Time intervals between initial and latest preoperative CT examination were 6-19 months (median, 14.5 months). Tumor doubling time according to CT findings was calculated as 46-407 days (median 106 days). CONCLUSION: Venous phase contrast-enhanced CT can provide findings that are suggestive of early pancreatic adenocarcinoma. Pancreatic phase contrast-enhanced CT should therefore be performed in patients with such findings with the aim of early detection of pancreatic adenocarcinoma. ADVANCES IN KNOWLEDGE: Pancreatic adenocarcinoma can develop subsequently in patients with non-pancreatic malignancies. Patients with non-pancreatic cancers are often followed up with monophasic contrast-enhanced CT in venous phase timing. Venous phase contrast-enhanced CT can provide some findings suggestive of early pancreatic adenocarcinoma. Knowledge of these findings is important for early detection of pancreatic adenocarcinoma.

Evaluation of juxtapapillary duodenal diverticula using multiplanar reformation in MDCT: correlation with ERCP findings.

OBJECTIVE: To determine the ability of multidetector computed tomography (MPR-MDCT) to identify and classify the juxtapapillary duodenal diverticulum (JPDD), with ERCP findings as the gold standard. METHODS: We retrospectively reviewed all ERCP examinations (n: 455) performed between January 2010 to December 2018 and selected 105 patients with JPDD as the inclusion criteria. Of those, 28 patients were excluded because of advanced pancreatic carcinoma, incomplete MDCT examinations and biliary catheter insertion. Finally, MDCT examinations of 77 patients with JPDD were assessed for the presence and type of JPDD. RESULTS: MPR-MDCT was able to identify 71 (92.2%) JPDD in 77 cases with 88.9% accuracy, 83.3% sensitivity, and 91.6% specificity in classifying the type of JPDD. MPR-MDCT performed best in determining type 1 JPDD, with accuracy of 95.4% compared with type 2 (83.3%) and type 3 (87.8%). There was no significant difference between age, gender, incidence of biliary stones and pancreatitis between each type of JPDD. No correlation of sizes with types of JPDD was found. CONCLUSIONS: MPR-MDCT can accurately identify and classify JPDD. This information will be useful in determining the difficulty of ERCP.

Invasive intraductal papillary mucinous neoplasms of the pancreas: relationships between mural nodules detected on thin-section contrast-enhanced MDCT and invasive components.

PURPOSE: To elucidate the relationships between mural nodules (MNs) and invasive components in patients with invasive intraductal papillary mucinous neoplasm (IPMN) on the basis of thin-section contrast-enhanced multidetector CT (CE-MDCT) and pathologic findings. METHODS: This retrospective study included 28 patients with surgically confirmed invasive IPMN. Two radiologists independently evaluated the thin-section (1-mm section thickness, no overlap) triple-phase CE-MDCT images for MNs, invasive components, and the continuity between them using a five-point scale (confidence scores of 1-3 as negative, 4 and 5 as positive). Kappa statistic was used to evaluate interobserver agreement. The CE-MDCT findings were correlated with pathologic findings. RESULTS: Interobserver agreement was good or excellent. MNs consisting of tumor cells were recognized in 12 (42.9%) of 28 patients with no discrepancy between the two radiologists. Invasive components were detected in 85.7% and 82.1% in the pancreatic parenchymal phase for radiologist 1 and 2, respectively, and recognized as hypoattenuating areas. Pathologic continuities between MNs and invasive components were confirmed in five (41.7%) of 12 patients with MNs and these were detected on CE-MDCT. When combined seven patients without continuities between MNs and invasive components and 16 patients without MNs, the invasive components pathologically derived from non-nodular low-height papillary epithelium in 23 (82.1%) of 28 patients. CONCLUSIONS: The invasive components derived more often from low-height papillary epithelium without MN appearance on CE-MDCT than from MN. Careful attention should be paid to the existence of an invasive component even in the absence of an enhancing MN.

Small pancreatic ductal carcinomas on triple-phase contrast-enhanced computed tomography: enhanced rims and the pathologic correlation.

PURPOSE: To reveal the prevalence of small (≤ 20 mm) pancreatic ductal carcinomas with enhanced rims on triple-phase contrast-enhanced CT and correlate the CT images with the pathologic findings. MATERIALS AND METHODS: Between April 2005 and April 2016, 45 patients underwent preoperative triple-phase contrast-enhanced CT and were pathologically diagnosed with small pancreatic ductal carcinoma. CT images were independently reviewed by two radiologists. The attenuation values of the enhanced rims, internal areas of the tumors, and surrounding pancreatic parenchyma were compared using Mann-Whitney U test. These areas were also correlated with the pathologic findings. Tumor invasiveness was compared between the tumors with and without enhanced rims using Fisher's exact test. RESULTS: Enhanced rims were identified in 18 tumors (40%) by consensus between the two reviewers. The enhanced rims showed significantly higher mean attenuation values compared with the internal areas of the tumors (p < 0.001) and surrounding pancreatic parenchyma (p < 0.0086), and were most clearly visualized on equilibrium phase. The enhanced rims pathologically reflected the abundant fibrotic stroma with cancer cells in all tumors. There was no statistically significant difference in tumor invasiveness between the tumors with and without enhanced rims (anterior peripancreatic invasion, p = 0.137; posterior peripancreatic invasion, p = 0.758; portal vein invasion, p = 0.639; and lymph node metastases, p = 0.359). CONCLUSIONS: Enhanced rims were detected at a rate of 40% in small pancreatic ductal carcinomas and could be an important finding for diagnosis on CT images, but did not suggest a less aggressive nature.

Fusion anomaly of the pancreatic tail and spleen: a case report.

BACKGROUND: Splenopancreatic fusion is a rare anomaly that is often associated with trisomy 13. Its diagnosis can be important in patients scheduled to undergo distal pancreatectomy or splenectomy, to avoid possible intraoperative or postoperative complications. CASE PRESENTATION: An 82-year-old Japanese man was referred to our hospital for further evaluation and treatment for a solitary hepatocellular carcinoma based on liver cirrhosis. Triple-phase contrast-enhanced multidetector-row computed tomography and magnetic resonance imaging showed a splenopancreatic fusion as well as a solitary hepatocellular carcinoma in segment VIII of his liver. CONCLUSIONS: Fusion of the pancreatic tail and spleen is a rare and asymptomatic anomaly. Its detection can be improved by the use of multidetector computed tomography or magnetic resonance imaging.

Contour variations of the body and tail of the pancreas: evaluation with MDCT.

PURPOSE: To analyze morphology/contour variations of the pancreatic body and tail in subjects free of pancreatic disease. METHODS: We retrospectively reviewed triple-phase, contrast-enhanced multi-detector row computed tomography (3P-CE-MDCT) examinations of 449 patients who had no clinical or CT evidence of pancreatic diseases. These patients were evaluated for morphologic/contour variations of the pancreatic body and tail, which were classified into two types. In Type I, a portion of normal pancreatic parenchyma protrudes >1 cm in maximum diameter from the body or tail (Ia-anteriorly; Ib-posteriorly). Type II was defined as a morphologic anomaly of the pancreatic tail (IIa-globular; IIb-lobulated; IIc-tapered; IId-bifid). RESULTS: Thirty-eight (8.5%) out of 449 patients had body or tail variations. Of those, 23 patients showed Type I variant: Ia in 21 and Ib in two. Type II variant was identified in 15 patients: IIa in eight, IIb in two, IIc in two and IId in three. Protrusion of the anterior surface of the normal pancreas, especially in the tail, was the most frequently occurring variant. CONCLUSIONS: Recognizing the types and subtypes of morphology/contour variations of the pancreatic body and tail could help prevent misinterpretation of normal variants as pancreatic tumors on unenhanced MDCT.

Periportal low attenuation associated with liver metastasis from colorectal cancer: evaluation using multi-detector-row CT with pathological correlation.

OBJECTIVES: Periportal low attenuation (PPLA) associated with metastatic liver cancer is occasionally seen on multi-detector-row CT (MDCT). The purpose of this study was to investigate the MDCT patterns of the PPLA and to correlate it with pathological findings. METHODS: We retrospectively reviewed the MDCT images of 63 patients with metastatic liver cancers from colorectal adenocarcinoma. On MDCT scans, PPLA associated with liver metastasis was visualized in six patients with colorectal cancer. In these six patients who had undergone surgical resection, the radiologic-pathologic correlation was analyzed. All patients underwent a single contrast-enhanced MDCT within 1 month before surgical resection. The six liver cancers were pathologically proven to be moderately differentiated adenocarcinoma. We assessed the PPLA on MDCT concerning the distribution patterns and contrast enhancement with pathological correlation. RESULTS: In five of the patients, the PPLA extended to the hilar side from metastatic liver cancer. Pathologically, there was no cancer invasion into the intra-hepatic periportal area; however, massive lymphedema and fibrosis occurred in all six cases. CONCLUSIONS: PPLA on the hilar and peripheral sides of hepatic metastasis from colorectal cancer may be present suggesting lymphedema and fibrosis of portal tracts not always indicating cancer infiltration.

Genomic Loss of DUSP4 Contributes to the Progression of Intraepithelial Neoplasm of Pancreas to Invasive Carcinoma.

The progression from precursor lesions of pancreatic cancer, including pancreatic intraepithelial neoplasia and intraductal papillary mucinous neoplasm (IPMN), to invasive disease is characterized by stepwise accumulation of genetic alterations. However, it remains unclear whether additional alterations are required for the progression of high-grade neoplasms to invasive pancreatic carcinoma. We compared the genomic profiles of paired noninvasive and invasive carcinoma tissues collected from patients with IPMN. We demonstrate that the frequency of genomic copy-number aberrations significantly increased during the course of invasion, and the loss of 8p11.22-ter was more often associated with invasive tissues. Expression profiling in pancreatic cancer cell lines with and without 8p11.22-ter revealed that DUSP4, an MAPK phosphatase, was significantly downregulated in cells lacking 8p11.22-ter as well as in invasive carcinomas due to genomic loss. Restoration of DUSP4 expression in pancreatic cancer cells significantly suppressed invasiveness and anoikis resistance via ERK inactivation. Accordingly, we found that blockade of ERK signaling by MEK inhibition was effective in an orthotopic xenograft model and significantly extended survival. Collectively, our findings demonstrate a genetic mechanism by which pancreatic precursor lesions progress to invasive carcinomas and highlight DUSP4 as a novel invasion suppressor that can be therapeutically exploited through manipulation of ERK signaling. Cancer Res; 76(9); 2612-25. ©2016 AACR.

Pancreatic neuroendocrine tumor with extensive intraductal invasion of the main pancreatic duct: a case report.

CONTEXT: Pancreatic neuroendocrine tumors account for only 1-3% of all pancreatic neoplasms and the intraductal invasion of the main pancreatic duct (MPD) is rare. CASE REPORT: We report a case of a 26-year-old woman with an endocrine tumor of the pancreas extensively invading into the MPD. She presented abdominal pain and her laboratory data showed abnormal liver function. Contrast-enhanced computed tomography demonstrated a well-enhanced mass on the arterial dominant phase in the head of the pancreas. The mass grew within the lumen of the MPD in the body of the pancreas, with dilatation of the upstream MPD. The contrast-enhancement pattern between the main tumor of the head and the intraductal lesion of the body was different. On T2-weighted magnetic resonance (MR) imaging, the pancreatic head lesion showed non homogeneously low signal intensity, while the intraductal lesion of the pancreatic body showed high signal intensity. MR cholangiopancreatography showed obstruction of the MPD in the pancreatic head to body, with dilatation of the upstream MPD. An endocrine tumor or acinar cell carcinoma of the pancreas was considered as preoperative diagnosis, and pancreaticoduodenectomy was performed. As a result, pancreatic endocrine tumor (G2) was confirmed pathologically. CONCLUSION: A rare case of pancreatic neuroendocrine tumor with extensive growth within the MPD was presented. The intraductal extension is a unique growth pattern of nonfunctioning pancreatic neuroendocrine tumor, and the desmoplastic reaction in this tumor may reflect the increased invasiveness.

Extrahepatic bile duct cancer: invasion of the posterior hepatic plexuses--evaluation using multidetector CT.

PURPOSE: To assess the utility of axial and coronal reformatted multidetector computed tomographic (CT) images in the evaluation of the invasion of posterior hepatic plexuses by extrahepatic bile duct cancer. MATERIALS AND METHODS: This retrospective study was approved by the institutional review board, and informed consent was waived. Forty-three patients (22 men, 21 women; age range, 40-80 years; mean age, 65 years) with surgically resected cancer involving the extrahepatic bile duct between December 2004 and September 2010 were included. Posterior hepatic plexus 1 runs from the superior and middle bile duct to the right celiac ganglion, and posterior hepatic plexus 2 runs between the lower bile duct and right celiac ganglion behind the portal vein. Invasion of the posterior hepatic plexuses was elucidated by using pathologic and postoperative multidetector CT findings. Three radiologists independently evaluated the preoperative axial and coronal reformatted images with a separate viewing session for the invasion of posterior hepatic plexuses that was detected on the basis of the presence of increased attenuation of fat tissue along the nerve routes. Receiver operating characteristic analysis was performed to compare the diagnostic performance of the two image interpretations. RESULTS: Invasion of posterior hepatic plexus 1 and of posterior hepatic plexus 2 was recognized in 10 (23%) and nine (21%) of 43 patients, respectively. The diagnostic performance of coronal reformatted image interpretation was significantly greater than that for axial image interpretation (mean area under the curve, 0.99 vs 0.89, P = .04; mean accuracy, 95% vs 82%, P = .003). In all reviewers, one false-positive diagnosis of the invasion of posterior hepatic plexus occurred on axial and/or coronal image display types because of fibrosis and inflammatory cell infiltration along these plexus routes. CONCLUSION: Coronal reformatted images can be useful for accurate diagnosis of the invasion of posterior hepatic plexuses and may facilitate surgical decision making in regard to the resection of celiac ganglion.

"Peripancreatic strands appearance" in pancreatic body and tail carcinoma: evaluation by multi-detector CT with pathological correlation.

OBJECTIVES: In pancreatic body and tail carcinoma, "peripancreatic strands appearance" is frequently seen on multidetector CT (MDCT). The purpose of this study was to clarify the pathological and clinical implications of peripancreatic strands appearance. METHODS: We retrospectively evaluated MDCT images in 17 patients with pancreatic body and tail carcinoma who underwent surgical resection. Peripancreatic strands appearance was defined as the strands structure deriving from the primary lesion and associated with increased CT attenuation of surrounding adipose tissues. All CT examinations were performed by contrast-enhanced MDCT with a multiplanar reformation technique. RESULTS: Peripancreatic strands appearance was detected on MDCT in 13 (76%) patients. The maximum width of the peripancreatic strands seen on MDCT was 1.55 ± 0.36 mm (range, 1.0-2.5 mm). This CT finding was well correlated with extrapancreatic carcinoma invasion with marked fibrotic thickening of adipose tissue septa, including microvessels. This pathological finding was confirmed in all 13 patients with positive CT finding whereas it was not confirmed in the 4 patients with negative CT finding. CONCLUSION: Peripancreatic strands appearance on MDCT in pancreatic body and tail carcinoma reflects extrapancreatic carcinoma invasion with marked fibrotic thickening of adipose tissue septa. This CT finding would indicate the property of carcinoma aggressiveness.

Intraductal papillary mucinous neoplasms of the pancreas complicated with intraductal hemorrhage, perforation, and fistula formation: CT and MR imaging findings with pathologic correlation.

OBJECTIVE: To correlate the CT and MR images with pathologic findings on intraductal papillary mucinous neoplasms (IPMNs) complicated with intraductal hemorrhage, perforation, and fistula. MATERIALS AND METHODS: We retrospectively evaluated the CT (n = 5), MR imaging (n = 4), and pathological features of five IPMN patients complicated with intraductal hemorrhage (n = 5), perforation (n = 1), and fistula into the duodenum and jejunum (n = 1). RESULTS: Intraductal hemorrhage could be detected as high attenuation on non-contrast CT in two of the five cases, and as high signal intensity on fat-suppressed T1-weighted MR images in all four of the cases. Perforation and fistula could be recognized on CT images. In all IPMNs, denuded epitheliums were observed pathologically. Dissolution of the duct wall and extension of mucinous materials were seen at the area of denuded epithelium. Perforations and fistula, without evidence of cancer invasion, were recognized in the dissolved duct wall. Pathogenesis of the perforations and fistula formations appeared to be related to excessive pressure in the dilated ducts and autodigestion of enzyme-rich fluids. CONCLUSION: Complications with IPMN could be recognized on CT and fat-suppressed T1-weighted MR images. Intraductal hemorrhage might be predictive sign of perforation and fistula formation.

Pancreatic adenocarcinoma versus chronic pancreatitis: differentiation with triple-phase helical CT.

BACKGROUND: Chronic pancreatitis and pancreatic adenocarcinoma often show similar clinical and imaging appearances. This study aims to differentiate chronic pancreatitis from pancreatic adenocarcinoma by defining enhancement patterns in both pathologic conditions during triple-phase helical CT. METHODS: The study included 42 patients with chronic pancreatitis and 85 patients with pancreatic adenocarcinoma. CT images obtained according to protocol A (scan delays, 30, 60, and 150 s; 300 mg I/mL contrast material) or protocol B (scan delays, 40, 70, and 150 s; 370 mg I/mL contrast material) were retrospectively evaluated. RESULTS: Mean contrast enhancement value of normal pancreas peaked in the first phase (early-washout pattern) while that of chronic pancreatitis peaked in the second phase (delayed-washout pattern), and that of pancreatic adenocarcinoma gradually rose (increasing pattern) in both protocols. Diagnostic indices for pancreatic adenocarcinoma were 82.4% and 94.1% for sensitivity, 83% and 83% for specificity, 82.7% and 90.4% for accuracy in protocols A and B, respectively, when differentiation between chronic pancreatitis and pancreatic adenocarcinoma was performed based on time-attenuation curve patterns. CONCLUSION: Our results indicate that time attenuation curves obtained from triple-phase helical CT in protocol B provide useful information in differentiating chronic pancreatitis from pancreatic adenocarcinoma.

Arterial supply to the pancreas; variations and cross-sectional anatomy.

The pancreas has complex arterial supplies. Therefore, special attention should be paid in pancreatic arterial intervention for patients with acute pancreatitis and pancreatic carcinomas. Knowledge of pancreatic arterial anatomy and arterial territory is important not only to perform pancreatic arterial intervention, but to read the pancreatic angiography and cross-sectional image. We reviewed 226 selective abdominal angiography and CT scans during selective arteriography (CTA) of common hepatic artery, superior mesenteric artery, splenic artery, or peripancreatic arteries including posterior superior pancreaticoduodenal artery, anterior superior pancreaticoduodenal artery, inferior pancreaticoduodenal artery, and dorsal pancreatic artery. CTA images were evaluated to clarify the cross-sectional anatomy of the pancreatic arterial territory. Variations of the peripancreatic arteries were also investigated. In this exhibit, schemes and illustrative cases demonstrate pancreatic arterial territory and variations.

Invasive carcinomas originating from intraductal papillary mucinous neoplasms of the pancreas: conspicuity and primary sites of the solid masses on triple-phase dynamic CT imaging.

OBJECTIVE: To assess the conspicuity of invasive carcinomas (solid masses) originating from pancreatic intraductal papillary mucinous neoplasms (invasive IPMNs) and the primary sites of the solid masses on thin-slice dynamic CT. METHODS: Twenty patients with pathologically proven invasive IPMNs underwent triple-phase dynamic CT examinations (arterial, portal, and delayed phases). Qualitative and quantitative analyses of conspicuity of the solid masses were performed for all phases. The primary sites [branch duct and/or main pancreatic duct (MPD)] of the solid masses were evaluated on CT in comparison to the pathologic findings. RESULTS: The qualitative and quantitative analyses of the conspicuity of the solid masses showed that the arterial phase images were superior to those of the portal and delayed phases. The primary sites of the solid mass were histopathologically diagnosed as branch ducts in 6 (30%) patients, MPD in 13 (65%), and both branch ducts and the MPD in one (5%). The sensitivity and specificity of the CT evaluation of the primary sites were 100% for the branch ducts, and for the MPD 93% and 100%, respectively. CONCLUSION: Arterial phase images are useful for the diagnosis of invasive IPMNs, and attention should be paid to pancreatic parenchyma surrounding the MPD when detecting invasive carcinomas.