Endoscopic ultrasound elastography for small solid pancreatic lesions with or without main pancreatic duct dilatation.

BACKGROUND: /Objectives: Endoscopic ultrasound elastography (EUS-EG) is useful for diagnosis of small solid pancreatic lesions (SPLs), particularly in excluding pancreatic cancer (PC), but its dependence on main pancreatic duct dilatation (MPDD) has not been examined. We aimed to investigate EUS-EG for diagnosis of small SPLs with and without MPDD. METHODS: Patients with pathologically diagnosed SPLs of ≤20 mm were included and retrospectively analyzed. Using the blue:green ratio, an EUS-EG image was classified as blue-dominant, equivalent, or green-dominant. Using multiple EUS-EG images per patient, a lesion with a greater number of blue-dominant than green-dominant images was classified as stiff, and the others as soft. EUS-EG images in random order were judged by three raters. Considering stiff SPLs as PC, diagnostic performance of EUS-EG was examined for SPLs with and without MPDD. RESULTS: Of 126 cases analyzed, 65 (52%) were diagnosed as PC, and 63 (50%) had MPDD. A total of 1077 EUS-EG images were examined (kappa coefficient = 0.783). Lesions were classified as stiff in 91 cases and soft in 35 (kappa coefficient = 0.932). The ratio of stiff to soft lesions was significantly higher in PC than in non-PC (62:3 vs. 29:32, P < 0.001). The sensitivity, specificity, and negative predictive value of a stiff lesion with vs. without MPDD for diagnosis of PC were 94%, 23%, and 50% vs. 100%, 60%, and 100%, respectively. CONCLUSIONS: Using the EUS-EG stiffness classification for small SPLs, PC can be excluded with high confidence and concordance for a soft lesion without MPDD.

Isolated Main Pancreatic Duct Dilatation: CT Differentiation Between Benign and Malignant Causes.

OBJECTIVE: The purpose of this study is to retrospectively evaluate the differential CT features of isolated benign and malignant main pancreatic duct (MPD) dilatation and to investigate whether the diagnostic performance of radiologists can be improved with knowledge of these differential CT features. MATERIALS AND METHODS: Forty-one patients who had isolated MPD dilatation without any visible mass on CT from January 2000 to October 2016 were retrospectively enrolled in the study. Two radiologists reviewed CT images in consensus for the location, shape (smooth vs abrupt), length of transition, dilated pancreatic duct (PD) diameter, presence of duct penetrating sign, parenchymal atrophy, attenuation difference, associated pancreatitis, calcification, PD or common bile duct (CBD) enhancement, and perilesional cyst. The chi-square test, Fisher exact test, and t test were used to find the differential CT features of benign and malignant MPD dilatation. Two successive review sessions for differentiation between the two disease entities were then independently performed by three other reviewers with differing expertise, with the use of a 5-point confidence scale. The first session provided no information for differentiation; however, reviewers were aware of the results of univariate analyses in the second session. The diagnostic performance of the radiologists was evaluated using a pairwise comparison of ROC curves. RESULTS: A total of 19 benign and 22 malignant MPD dilatations were identified. In patients with benign MPD dilatation, transition areas were frequently located in the head (57.9% [11/19] vs 13.6% [3/22], p = 0.003) and showed significantly shorter (< 6.1 mm) (78.9% [15/19] vs 9.1% [2/22], p < 0.0001) and smooth transition (89.5% [17/19] vs 9.1% [2/22], p < 0.0001). Duct penetrating sign was exclusively observed in patients with benign MPD dilatation (73.7% [14/19] vs 0% [0/22], p < 0.0001). In contrast, malignant MPD dilatation frequently was accompanied by attenuation difference (63.6% [14/22] vs 10.5% [2/19], p = 0.001) and associated PD or CBD enhancement (36.4% [8/22] vs 0% [0/19], p = 0.003). The AUC values of three reviewers significantly increased from 0.653, 0.587, and 0.884 to 0.864, 0.964, and 0.908, respectively, with knowledge of significant CT features (p = 0.013, p < 0.0001, and p = 0.701, respectively). CONCLUSION: Distal, long (≥ 6.1 mm), and abrupt transition, the absence of duct penetrating sign, and the presence of attenuation difference and PD or CBD enhancement were highly suggestive CT findings for differentiation of malignant from benign MPD dilatation. The diagnostic performance of radiologists with regard to differentiation was significantly improved with knowledge of these highly suggestive CT criteria.

Temporal progression of pancreatic cancer computed tomography findings until diagnosis: A large-scale multicenter study.

BACKGROUND: Focal parenchymal atrophy and main pancreatic duct (MPD) dilatation have been identified as early signs of pancreatic ductal adenocarcinoma. However, limited evidence exists regarding their temporal progression due to previous study limitations with restricted case numbers. OBJECTIVE: To ascertain a more precise frequency assessment of suspicious pancreatic ductal adenocarcinoma findings as well as delineate the temporal progression of them. METHODS: A multicenter retrospective study was conducted on patients diagnosed with pancreatic ductal adenocarcinoma between 2015 and 2021. We included patients who had undergone at least one computed tomography (CT) scan ≥6 months before diagnosing pancreatic ductal adenocarcinoma. The temporal progression of suspicious pancreatic ductal adenocarcinoma findings on CT was investigated. RESULTS: Out of 1832 patients diagnosed with pancreatic ductal adenocarcinoma, 320 had a previous CT before their diagnosis. Suspicious pancreatic ductal adenocarcinoma findings were detected in 153 cases (47.8%), with focal parenchymal atrophy (26.6%) being the most common followed by MPD dilatation (11.3%). Focal parenchymal atrophy was the earliest detectable sign among all suspicious findings and became visible on average 2.7 years before diagnosis, and the next most common, MPD dilatation, 1.1 years before diagnosis. Other findings, such as retention cysts, were less frequent and appeared around 1 year before diagnosis. Focal parenchymal atrophy followed by MPD dilatation was observed in 10 patients but not in reverse order. Focal parenchymal atrophy was more frequently detected in the pancreatic body/tail. No significant relationship was found between the pathological pancreatic ductal adenocarcinoma differentiation or tumor stage and the time course of the CT findings. All cases of focal parenchymal atrophy progressed just prior to diagnosis, and the atrophic area was occupied by tumor at diagnosis. Main pancreatic duct dilatation continued to progress until diagnosis. CONCLUSION: This large-scale study revealed that the temporal progression of focal parenchymal atrophy is the earliest detectable sign indicating pancreatic ductal adenocarcinoma. These results provide crucial insights for early pancreatic ductal adenocarcinoma detection.

Focal Parenchymal Atrophy of the Pancreas Is Frequently Observed on Pre-Diagnostic Computed Tomography in Patients with Pancreatic Cancer: A Case-Control Study.

Pancreatic ductal adenocarcinoma (PDAC) accounts for the majority of all pancreatic cancers and is highly lethal. Focal parenchymal atrophy (FPA) of the pancreas has been reported as a characteristic imaging finding of early PDAC. Here, we reviewed 76 patients with PDAC who underwent computed tomography (CT) between 6 months and 3 years before PDAC diagnosis, as well as 76 sex- and age-matched controls without PDAC on CT examinations separated by at least 5 years. FPA was observed corresponding to the location of the subsequent tumor on pre-diagnostic CT in 14/44 (31.8%) patients between 6 months and 1 year, 14/51 (27.5%) patients between 1 and 2 years, and 9/41 (22.0%) patients between 2 and 3 years before PDAC diagnosis. Overall, FPA was more frequently observed in patients with PDAC (26/76; 34.2%) on pre-diagnostic CT than that in controls (3/76; 3.9%) (p < 0.001). FPA was observed before the appearance of cut-off/dilatation of the main pancreatic duct, suggesting that FPA might be the earliest sign of PDAC. FPA was less frequently found in tumors in the pancreatic head (3/27; 11.1%) than in those in the body (14/30; 46.7%) or tail (9/19; 47.4%). FPA may predict the subsequent PDAC diagnosis, serving as an important imaging sign for the early diagnosis of pancreatic cancer.

Solid pseudopapillary neoplasm of the pancreas in a young male with main pancreatic duct dilatation: A case report.

BACKGROUND: Solid pseudopapillary neoplasms (SPNs) are rare tumors of the pancreas. Typically, they occur in young females, often have characteristic imaging features, such as cystic components and calcification, and have few effects on the pancreatic duct. CASE SUMMARY: A 31-year-old man was admitted to our hospital with the chief complaint of epigastric pain. There was only mild tenderness in his upper abdomen, and blood tests showed only a slight increase in alkaline phosphatase. Contrast-enhanced computed tomography showed a 40-mm-diameter, hypovascular mass in the head of the pancreas, and the main pancreatic duct upstream of the mass was severely dilated. Magnetic resonance imaging showed low intensity on T1-weighted images, with high intensity on T2-weighted image in some parts. Pancreatic ductal adenocarcinoma was the primary differential diagnosis. Portal vein infiltration could not be ruled out, so this case was a candidate for neoadjuvant chemotherapy. Subsequently, endoscopic ultrasound-guided fine needle aspiration was performed, and pathological evaluation and immunostaining suggested a diagnosis of SPN. Thus, pancreatoduodenectomy was performed. One year after the operation, the patient is alive with no recurrence. CONCLUSION: Main pancreatic duct dilatation is usually a finding of suspected pancreatic cancer. However, pancreatic duct dilatation can occur in SPN depending on the location and growth speed. Therefore, SPN should be considered in the differential diagnosis of tumors with pancreatic duct dilatation, and pathological evaluation by endoscopic ultrasound-guided fine needle aspiration should be actively performed.

Acute pancreatitis-onset carcinoma in situ of the pancreas with focal fat replacement diagnosed using serial pancreatic-juice aspiration cytologic examination (SPACE).

A 59-year-old woman was admitted for acute pancreatitis. Abdominal computed tomography and magnetic resonance imaging revealed a swollen pancreatic parenchyma with dilatation of the main pancreatic duct (MPD) of the pancreas tail, which was separated from the normal pancreas body side by a locally atrophic part of the pancreas. Magnetic resonance cholangiopancreatography showed MPD stricture in the pancreas tail with dilatation of the upstream MPD. Endoscopic ultrasonography revealed that the MPD stricture of the pancreas tail was surrounded by a blurred and hypoechoic area. Endoscopic retrograde cholangiopancreatography was performed for serial pancreatic-juice aspiration cytologic examination (SPACE). The result indicated adenocarcinoma. Distal pancreatectomy was performed, and the histopathological examination showed high-grade PanIN (carcinoma in situ of the pancreatic duct) of the pancreas tail with atrophy and fibrosis of the pancreatic parenchyma, and local fat replacement adjacent to the lesion. The final histopathological diagnosis was carcinoma in situ of the pancreatic duct of the pancreas tail. Acute pancreatitis and local fatty change of the pancreatic parenchyma with MPD stricture are important clinical manifestations of pancreatic carcinoma in situ (PCIS) and performing SPACE in cases of MPD stricture without a recognizable mass is preferable for a diagnosis of PCIS.

Clinical and radiologic characteristics of pancreatic head carcinoma without main pancreatic duct dilatation: using dual-phase contrast-enhanced CT scan.

PURPOSE: The purpose was to evaluate characteristics of pancreatic cancer without main pancreatic duct (MPD) dilatation on dual-phase computed tomographic (CT) scans. MATERIALS AND METHODS: We studied 16 patients with pancreatic head cancer without accompanying MPD dilatation and 39 patients with MPD dilatation RESULTS: Elevation of serum amylase level and peripancreatic fluid collection were more frequently seen in the MPD(-). Common bile duct dilatation and atrophy of the upstream pancreatic parenchyma were more frequently seen in MPD(+). CONCLUSION: Pancreatic cancers without MPD dilatation were more frequently related to acute pancreatitis and had fewer secondary signs. Thus, early diagnosis of pancreatic cancer with these characteristics could be difficult.

Pancreatic cancer: Slow progression in the early stages.

INTRODUCTION: The rates of pancreatic cancer development in the early stages of growth remain unclear; but it is generally believed that they demonstrate a rapid degree of progression. There is evidence to suggest that pancreatic cancers measuring less than 1cm demonstrate better survival rates, hence it is clear that detecting pancreatic cancers less than 1cm in size is of paramount importance. However, to date, there has been no scientifically adequate research to show the growth rate of small pancreatic cancers less than 1cm in the early stages. PRESENTATION OF CASE: We present the case of a 65-year-old woman whose small pancreatic cancer possibly demonstrated a slow progressive rate as it grew to an invasive carcinoma measuring 1cm diameter from over the 29 months. DISCUSSION: It is reasonable to assume that the progression of some pancreatic cancers until 1cm size, can take up to 29 months. During this silent period, it is crucial to detect such a small pancreatic cancer by means of the initial US and subsequent EUS and ERCP. It is clear, therefore, that clinicians have to be aware of the growth rate of small pancreatic cancers and in particular high risk patients should be encouraged to monitor size of the main pancreatic duct by means of US on regular basis. CONCLUSION: This could give better outcomes for pancreatic cancer patients. Hopefully, by detecting these lethal, pancreatic cancers in their early stages, it will give us an extension of time to perform effective therapies.