Imaging of early pancreatic cancer on multidetector row helical computed tomography

Assessment of main pancreatic duct cutoff with dilatation, but without visible pancreatic focal lesion on MDCT: a novel diagnostic approach for malignant stricture using a CT-based nomogram

OBJECTIVES

To identify useful features to predict hidden pancreatic malignancies in patients with main pancreatic duct (MPD) abrupt cutoff and dilatation, but without visible focal pancreatic lesions on CT.

METHODS

This retrospective study included 92 patients (mean age, 63.4 ± 10.6 years, 63 men and 29 women) with MPD abrupt cutoff and dilatation, but without visible focal pancreatic lesion on contrast-enhanced CT between 2009 and 2021. Two radiologists independently evaluated the CT imaging features. Multivariable logistic regression analysis was performed to identify clinical and CT imaging features for hidden pancreatic malignancies. A nomogram was developed based on these results and assessed its performance.

RESULTS

Thirty-eight (41.3%) and 54 (58.7%) were classified into the malignant and benign groups, respectively. In the multivariable analysis, CA19-9 elevation (odds ratio [OR] 7.5, p = 0.003), duct cutoff site at the head/neck (OR 7.6, p = 0.006), parenchymal contour abnormality at the duct cutoff site (OR 13.7, p < 0.001), and presence of acute pancreatitis (OR 11.5, p = 0.005) were independent predictors of pancreatic malignancy. A combination of any two significant features showed an accuracy of 77.2%, and a combination of any three features exhibited a specificity of 100%. The CT-based nomogram showed an area under the curve (AUC) of 0.84 (95% confidence interval, 0.77-0.90).

CONCLUSIONS

The three CT imaging features and CA19-9 elevation translated into a nomogram permit a reliable estimation of hidden pancreatic malignancies in patients with MPD abrupt cutoff without visible focal pancreatic lesion. It may facilitate determining whether to proceed to further diagnostic tests.

KEY POINTS

• Isoattenuating pancreatic ductal adenocarcinoma can manifest only as an isolated main pancreatic duct (MPD) dilatation with abrupt cutoff, making it difficult to distinguish from benign strictures. • Along with the serum CA 19-9 elevation, MPD cutoff site at the pancreas head or neck, parenchymal contour abnormality at the duct cutoff site, and associated acute pancreatitis indicated a higher probability of the malignant MPD strictures. • The CT-based nomogram provided excellent diagnostic performance (AUC of 0.84) for hidden pancreatic malignancies in patients with MPD abrupt cutoff and dilatation.

Multi-Phase, Contrast-Enhanced Computed Tomography-Based Radiomic Prognostic Marker of Non-Metastatic Pancreatic Ductal Adenocarcinoma

Background/Aim: This study investigated the predictive ability of intra-tumor enhancement on computed tomography (CT) for the outcomes of patients with pancreatic ductal adenocarcinoma (PDA). Methods: Multi-phase, contrast-enhanced CT (including unenhanced, pancreatic parenchymal phase (PPP) and portal venous phase (PVP)) images of patients diagnosed with non-metastatic PDA were analyzed to investigate prognostic factors. Results: Two hundred ninety-eight patients with PDA (159 with resectable pancreatic cancer (RPC) and 139 with borderline resectable pancreatic cancer (BRPC)/locally advanced pancreatic cancer (LAPC)) were included. The attenuation values of PDA during the PPP (94.5 vs. 60.7 HU; p <0.001) and PVP (101.5 vs. 75.5 HU; p <0.001) were higher in patients with RPC than in those with BRPC/LAPC. Well-enhanced PDA during the PPP was associated with longer overall survival in the RPC group (27.9 vs. 15.4 months; p <0.001) and the BRPC/LAPC group (22.7 vs. 13.6 months; p = 0.024). Patients with BRPC/LAPC who underwent neoadjuvant treatment and had well-enhanced PDA during the PPP were more likely to undergo resection. Although tumor size was also an independent prognostic factor, it was not correlated with intra-tumoral enhancement during the PPP. Conclusions: Intra-tumoral contrast enhancement on CT is an independent prognostic factor in patients with non-metastatic PDA.

Factors associated with missed and misinterpreted cases of pancreatic ductal adenocarcinoma

OBJECTIVES

To retrospectively examine US, CT, and MR imaging examinations of missed or misinterpreted pancreatic ductal adenocarcinoma (PDAC), and identify factors which may have confounded detection or interpretation.

METHODS

We reviewed 107 examinations in 66/257 patients (26%, mean age 73.7 years) diagnosed with PDAC in 2014 and 2015, with missed or misinterpreted imaging findings as determined by a prior study. For each patient, images and reports were independently reviewed by two radiologists, and in consensus, the following factors which may have confounded assessment were recorded: inherent tumor factors, concurrent pancreatic pathology, technical limitations, and cognitive biases. Secondary signs of PDAC associated with each examination were recorded and compared with the original report to determine which findings were missed.

RESULTS

There were 66/107 (62%) and 49/107 (46%) cases with missed and misinterpreted imaging findings, respectively. A significant number of missed tumors were < 2 cm (45/107, 42%), isoattenuating on CT (32/72, 44%) or non-contour deforming (44/107, 41%). Most (29/49, 59%) misinterpreted examinations were reported as uncomplicated pancreatitis. Almost all examinations (94/107, 88%) demonstrated secondary signs; pancreatic duct dilation was the most common (65/107, 61%) and vascular invasion was the most commonly missed 35/39 (90%). Of the CT and MRIs, 28 of 88 (32%) had suboptimal contrast dosing. Inattentional blindness was the most common cognitive bias, identified in 55/107 (51%) of the exams.

CONCLUSION

Recognizing pitfalls of PDAC detection and interpretation, including intrinsic tumor features, secondary signs, technical factors, and cognitive biases, can assist radiologists in making an early and accurate diagnosis.

KEY POINTS

• There were 66/107 (62%) and 49/107 (46%) cases with missed and misinterpreted imaging findings, respectively, with tumoral, technical, and cognitive factors leading to the misdiagnosis of pancreatic ductal adenocarcinoma. • The majority (29/49, 59%) of misinterpreted cases of pancreatic ductal adenocarcinoma were mistaken for pancreatitis, where an underlying mass or secondary signs were not appreciated due to inflammatory changes. • The most common missed secondary sign of pancreatic ductal adenocarcinoma was vascular encasement, missed in 35/39 (90%) of cases, indicating the importance of evaluating the peri-pancreatic vasculature.

Factors affecting the accuracy of endoscopic ultrasound-guided fine needle aspiration for the diagnosis of small (≤20 mm) pancreatic lesions

To explore the diagnostic value of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) for small, solid or semi-solid pancreatic lesions (≤20 mm) and the factors affecting its accuracy.

METHODS

Altogether 92 patients with small, solid or semi-solid pancreatic lesions who underwent EUS-FNA at the Nanjing Drum Tower Hospital from November 2009 to January 2019 were retrospectively analyzed. Univariate and multivariate analyses were used to determine the factors affecting the accuracy of EUS-FNA for detecting these lesions.

RESULTS

Among the 92 cases, 56 (60.9%) were diagnosed as having malignant lesions and 36 (39.1%) as benign lesions, respectively. The overall sensitivity, specificity and accuracy of EUS-FNA for the diagnosis of small, solid or semi-solid pancreatic lesions were 71.4%, 100% and 82.6%, respectively. When considering the impact of the presence of a tissue core on the diagnosis, the sensitivity, specificity, and accuracy of EUS-FNA with tissue core compared with those based on cytology alone were 77.3% vs 50.0%; 100% vs 100%; and 86.8% vs 62.5%, respectively. The multivariate analysis showed that larger tumor size (>15-20 mm) (odds ratio [OR] 4.200, 95% confidence interval [CI] 1.21-14.53, P = 0.023) and histologic diagnosis based on tissue core (OR 4.593, 95% CI 1.03-20.47, P = 0.046) were related to a higher accuracy of EUS-FNA. Adverse events were observed in three patients, all were treated conservatively and recovered within 3 days.

CONCLUSIONS

EUS-FNA is effective and safe for diagnosing small pancreatic lesions. Tumor size and presence of tissue core are related to higher accuracy of the EUS-FNA.

Incidentally detected pancreatic adenocarcinomas on computed tomography obtained during the follow-up for other diseases

PURPOSE

To determine imaging findings of pancreatic adenocarcinomas incidentally detected on contrast-enhanced multiphasic dynamic computed tomography (CT) obtained during the follow-up for other diseases.

METHODS

From January 2007 to December 2018, 14 patients with pancreatic adenocarcinomas incidentally detected on CT obtained during the follow-up for other diseases (incidental group) and 105 patients with pancreatic adenocarcinomas symptomatically detected on ultrasound or CT (non-incidental group) were included. Imaging characteristics of the tumor were compared between the two groups. Additionally, imaging findings prior to the detection of a tumor on previous CT images in the incidental group were also assessed.

RESULTS

In cancers of the pancreas body/tail, there was a significantly smaller tumor size (median, 17 mm vs. 42 mm, p < 0.001), a significantly lower incidence of loss of fatty marbling (p = 0.025), vascular involvement (p < 0.001), lymph node metastasis (p = 0.046) and distant metastasis (p = 0.017), and a significantly higher incidence of preserved lobulation (p < 0.001) in the incidental group than in the non-incidental group. Regarding the cancers of the pancreas head, there were no significant differences in the radiological findings between the two groups. On previous CT images, small pancreatic nodules, secondary signs, and loss of fatty marbling tended to be the preceding findings of incidental pancreatic adenocarcinomas.

CONCLUSION

Incidentally detected pancreatic adenocarcinomas in the pancreas body/tail were characterized by an earlier tumor stage than in cases of symptomatically detected pancreatic adenocarcinoma. Several CT findings prior to the detection of a tumor may be useful for the early detection of pancreatic adenocarcinoma during the follow-up for other diseases.

Tumor heterogeneity of pancreas head cancer assessed by CT texture analysis: association with survival outcomes after curative resection

The value of image based texture features as a powerful method to predict prognosis and assist clinical management in cancer patients has been established recently. However, texture analysis using histograms and grey-level co-occurrence matrix in pancreas cancer patients has rarely been reported. We aimed to analyze the association of survival outcomes with texture features in pancreas head cancer patients. Eighty-eight pancreas head cancer patients who underwent preoperative CT images followed by curative resection were included. Texture features using different filter values were obtained. The texture features of average, contrast, correlation, and standard deviation with no filter, and fine to medium filter values as well as the presence of nodal metastasis were significantly different between the recurred (n = 70, 79.5%) and non-recurred group (n = 18, 20.5%). In the multivariate Cox regression analysis, lower standard deviation and contrast and higher correlation with lower average value representing homogenous texture were significantly associated with poorer DFS (disease free survival), along with the presence of lymph node metastasis. Texture parameters from routinely performed pre-operative CT images could be used as an independent imaging tool for predicting the prognosis in pancreas head cancer patients who underwent curative resection.

Time to Progression of Pancreatic Cancer: Evaluation with Multi-Detector Computed Tomography

PURPOSE

The aim of this study is to evaluate the natural history of untreated pancreatic cancer, with a particular emphasis on the growth rate of primary tumor and development of metastatic disease.

METHODS

One hundred patients with histologically proven pancreatic ductal adenocarcinoma examined with at least two CT scans with no intervening treatment were included. Tumor diameters and volumes were measured in CT scans and tumor growth rates and volume doubling times (VDTs) were calculated. The relationship between initial tumor size, growth rate, and distant metastasis development were investigated.

RESULTS

Included tumors were 1.0-6.2 cm (mean, 2.9 ± 1.3 cm) in diameter and 5.5-1225.9 cm³ (mean, 120.6 ± 158.9 cm³) in volume at the initial CT. Tumor growth rates were -0.4 to 19.9 cm/year (mean, 4.2 ± 3.8 cm/year) in diameter, and 11.1-13,321.5 cm³/year (mean, 727.8 ± 1609.5 cm³/year) in volume corresponding to VDT of 20.0-976.8 days (mean, 132.3 ± 132.1 days). The growth rate was significantly associated with the initial diameter and volume (p < 0.001). The development of distant metastasis was significantly associated with initial diameter (p < 0.05), volume (p = 0.015), and volume growth rate (p = 0.002).

CONCLUSIONS

The growth rate and VDTs of untreated pancreatic cancers varied widely, from less than a month to more than 4 years, positively associated with tumor size. The small tumors tend to grow slowly and have low risk for developing metastasis.

Utility of Endoscopic Ultrasonography Screening for Small Pancreatic Cancer and Proposal for a New Scoring System for Screening

OBJECTIVES

This study aimed to evaluate the utility of endoscopic ultrasonography screening for small pancreatic cancer (PC) and propose a new simple scoring system for selecting individuals who should be screened.

METHODS

Risk factors or symptoms related to PC were tentatively divided into high- and low-grade risk groups based mainly on reported relative risk values. Numbers of risk factors were designated as risk scores. Endoscopic ultrasonography screening was performed for 632 individuals. We analyzed scores for PC detection prospectively, and risk factors and scores of PC patients retrospectively.

RESULTS

We detected 10 small malignant pancreatic neoplasms (size ≤20 mm; 8 PCs; 9 Tis or T1) and 14 advanced PCs. All small PCs and 95.5% of PCs were found in individuals with low-grade risk scores of at least 3 points (P) or high-grade risk scores of at least 1P. Both average risk scores were significantly higher in patients with small PCs (P ≤ 0.04). Cutoffs for low- and high-grade risk scores implying the presence of small PC and all PC were 3P and 1P, respectively. When subjects having one or both cutoff scores were screened, sensitivity and specificity were 100% and 64.4% for small PCs and 95.5% and 64.4% for all PCs.

CONCLUSION

Endoscopic ultrasonography screening combining new scoring is effective for detecting small PC.

Systematic evaluation of radiological findings in the assessment of resectability of peri-ampullary cancer by CT using different contrast phase protocols

AIMS

To determine the relative significance of radiological signs in determining the resectability of peri-ampullary cancer (PC) and to assess the value of multi-phase imaging in detecting these findings.

MATERIALS AND METHODS

Blinded, double re-reporting of preoperative imaging from five hospitals was undertaken of 411 patients undergoing surgery for PC over an 8-year period, of whom 119 patients were found to be inoperable at the time of surgery.

RESULTS

The median tumour size was 26.7 mm and the proportion of patients reported to have regional lymphadenopathy (RL), venous (VI) and arterial involvement (AI) was 24.7%, 11.5%, and 3.9%, respectively and was similar regardless of the number of contrast phases undertaken. Significant associations were, however, noted between individual risk factors: VI was closely associated with tumour size (p=0.002) and AI (p<0.0001). In multivariate analysis AI, VI, and RL were independently associated with resectability (relative risk of resection=0.05, 0.31, and 0.51, respectively). Tumour size, however, was not associated with resectability when VI was included in the multivariate model.

CONCLUSIONS

The use of multiple vascular contrast phases has no measureable impact on the rate of determination of tumour resectability of PC. In preoperative staging, AI is the most significant adverse finding for resectability. Large tumour diameter is not an adverse finding in isolation from other risk factors.

Prediction of Vascular Invasion Using a 3-Point Scale Computed Tomography Grading System in Pancreatic Ductal Adenocarcinoma: Correlation With Surgery

OBJECTIVE

The aim of this study was to evaluate the correlation between a 3-point scale multidetector computed tomography (MDCT) grading system and surgical exploration in predicting vascular invasion and resectability in patients with pancreatic ductal adenocarcinoma (PDA).

METHODS

Fifty-five patients with surgical and pathologic confirmation of PDA were retrospectively analyzed by 3 radiologists independently. All patients had MDCT examination with multiplanar reformatted images, computed tomography (CT) angiography, and negative-contrast CT cholangiopancreatography (nCTCP). A 3-point scale CT grading system and criteria for unresectability adopting the latest guidelines were used in predicting the correlation between the invasion and resectability of 5 peripancreatic vessels and surgical grade and pathology.

RESULTS

Tumor location was correctly identified in all patients including 2 isodense lesions by means of nCTCP. The mean sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of MDCT were 92%, 83%, 95%, 78%, and 90%, respectively, in predicting tumor resectability compared with surgery and pathology and with good agreement (κ = 0.72-0.77). A correlation was observed between CT and surgical grade in predicting vascular invasion on a per-vessel basis, and the agreement presented as good to excellent (κ = 0.66-1.00).

CONCLUSIONS

A 3-point scale CT grading system is a simple and practical method in predicting peripancreatic vessel invasion and, importantly, correlates with surgical grade and pathology. Axial images combined with multiplanar reformation, nCTCP, and CT angiography can strengthen the comprehensive evaluation of PDA for resectability.

Presurgical Evaluation of Pancreatic Cancer: A Comprehensive Imaging Comparison of CT Versus MRI

OBJECTIVE

The purpose of this study was to compare comprehensive CT and MRI in the presurgical evaluation of pancreatic cancer.

MATERIALS AND METHODS

Thirty-eight patients with pathologically proven pancreatic cancer were included in a retrospective study. CT with negative-contrast CT cholangiopancreatography and CT angiography (CTA) (CT image set) versus MRI with MRCP and MR angiography (MRI image set) were analyzed independently by two reviewers for tumor detection, extension, metastasis, vascular invasion, and resectability. These results were compared with the surgical and pathologic findings.

RESULTS

The rate of detection of tumors was higher with MRI than with CT but not significantly so (reviewer 1, p = 1.000; reviewer 2, p = 0.500). In the evaluation of vessel involvement, nodal status, and resectability, although CT had higher ROC AUC values than did MRI (reviewer 1, 0.913 vs 0.858, 0.613 vs 0.503, and 0.866 vs 0.774; reviewer 2, 0.879 vs 0.849, 0.640 vs 0.583, and 0.830 vs 0.815), the differences were not statistically significant (p = 0.189 vs 0.494, 0.328 vs 0.244, and 0.193 vs 0.813 for reviewers 1 and 2). In the evaluation of tumor extension and organ metastases in the 38 patients, correct diagnosis of one of two liver metastases was achieved with both image sets, one case of omental and one case of peritoneal seeding were underestimated, and one case of stomach invasion was overestimated.

CONCLUSION

MRI and CT had similar performance in the presurgical evaluation of pancreatic cancer.

Effective screening for early diagnosis of pancreatic cancer

Diagnosis of pancreatic cancer (PC) at an early stage with curative surgery should improve long-term patient outcome. At present, improving survival should lie in identifying those cases with high-risk factors or precursor lesions through an effective screening including ultrasonography, some biological markers, or national familial pancreatic cancer registration. Recently, cases with PC < 10 mm with a favorable prognosis have been reported. For the diagnoses of cases with PC < 10 mm, the rate of tumor detection was higher on endoscopic ultrasonography (EUS) than on CT or other modalities, and EUS-guided fine needle aspiration was helpful in confirming the histologic diagnosis. Additionally, for the diagnosis of cases with PC in situ, EUS and magnetic resonance cholangiopancreatography (MRCP) may play important roles in detecting the local irregular stenosis of the pancreatic duct. Cytodiagnosis of pancreatic juice using endoscopic nasopancreatic drainage multiple times may be useful in the final diagnosis.

Pancreatic cancer serum biomarker PC-594: Diagnostic performance and comparison to CA19-9

AIM: To investigate serum PC-594 fatty acid levels as a potential biomarker in North American pancreatic cancer (PaC) patients, and to compare its performance to CA19-9.

METHODS: Using tandem mass spectrometry, we evaluated serum PC-594 levels from 84 North American patients with confirmed PaC and 99 cancer-free control subjects. We determined CA19-9 levels by ELISA. Significance between PaC patients and controls, and association with clinical variables was determined by analysis of variance and t-tests. Diagnostic performance was evaluated by receiver-operator characteristic (ROC) curve analysis, and PC-594 correlation with age and CA19-9 determined by regression analysis.

RESULTS: Mean PC-594 levels were 3.7 times lower in PaC patients compared to controls (P < 0.0001). The mean level in PaC patient serum was 0.76 ± 0.07 μmol/L, and the mean level in control subjects was 2.79 ± 0.15 μmol/L. There was no correlation between PC-594 and age, disease stage or gender (P > 0.05). Using 1.25 μmol/L as a PC-594 threshold produced a relative risk (RR) of 9.4 (P < 0.0001, 95%CI: 5.0-17.7). The area under the receiver-operator characteristic curve (ROC-AUC) was 0.93 (95%CI: 0.91-0.95) for PC-594 and 0.85 (95%CI: 0.82-0.88) for CA19-9. Sensitivity at 90% specificity was 87% for PC-594 and 71% for CA19-9. Six PaC patients with CA19-9 above 35 U/mL showed normal PC-594 levels, while 24 PaC patients with normal CA19-9 showed low PC-594 levels. Eighty-five of the 99 control subjects (86%) showed normal levels of both markers.

CONCLUSION: PC-594 biomarker levels are significantly reduced in North American PaC patients, and showed superior diagnostic performance compared to CA19-9.

Diagnostic strategies for early pancreatic cancer

Diagnosis of pancreatic cancer (PC) at an early stage with curative surgery is the approach with the potential to significantly improve long-term patient outcome. Recently, some reports showed that patients with pancreatic tumors smaller than 10 mm showed a favorable prognosis. However, the rate of tumor detection on computed tomography in patients with small pancreatic tumors is low. For the diagnoses of PC with tumors smaller than 10 mm, the rate of tumor detection was higher on endoscopic ultrasonography (EUS) than on computed tomography or other modalities, and histologic diagnosis using EUS-guided fine-needle aspiration was helpful in confirming the diagnosis. For the diagnosis of PC in situ, EUS and magnetic resonance cholangiopancreatography may play important roles in detecting the local irregular stenosis of the pancreatic duct. Endoscopic retrograde pancreatography and sequential cytodiagnosis using pancreatic juice obtained by endoscopic nasopancreatic drainage multiple times was useful in the final diagnosis of PC in situ. At present, improving survival lies in identifying those individuals with high-risk factors or precursor lesions through an effective screening method. For example, these should include ultrasonography, various biological markers, or national familial pancreatic cancer registration. Additionally, the relationship between specialists in PC from medical centers and practicing physicians plays an important role in the early diagnosis of PC.

Poor prognosis of common-type invasive ductal carcinomas that originate in the branching pancreatic duct

PURPOSE

To clarify the incidence, clinicopathological features and prognosis of pancreatic invasive ductal carcinomas (IDCs) with different tumor origin sites in the pancreatic duct.

METHODS

Based on the relationship between the invasive cancer area (ICA) and the main pancreatic duct (MPD), IDCs less than 2 cm in diameter were classified into two groups: type I, in which the ICA and MPD were separated, and type II, in which the MPD passed through the ICA. The clinicopathological findings and prognosis of each type were compared in a total of 37 patients.

RESULTS

The incidences of IDC types I and II were 18.9 and 81.1 %, respectively. Although there was no difference in local invasion, both node involvement and venous invasion tended to occur more frequently in type I IDC, and the three-year survival rate was significantly lower for type I (28.6 %) than type II (71.8 %) IDC.

CONCLUSIONS

The prognosis of IDCs that originated in the branching pancreatic duct (BPD) distant from the MPD (type I) was worse than the prognosis of IDCs that originated in either the MPD or the BPD close to the MPD (type II). These data suggest that the progression and degree of malignancy of IDCs may vary depending on the site of tumor origin in the pancreatic duct.

Primary solid pancreatic tumors: recent imaging findings updates with pathology correlation

The imaging findings of primary solid pancreatic tumors have long been studied and are generally well-established. However, interestingly enough, a wealth of new information has recently appeared in the literature, including the imaging findings of novel or previously seldom-addressed pathological entities as well as atypical imaging findings of common tumors, both of which are well-correlated with the pathology findings. 5 %-14 % of pancreatic ductal adenocarcinomas have been reported on dynamic contrast-enhanced computed tomography to be isoattenuating, and thus making the imaging diagnosis challenging. The imaging-pathology correlation in such isoattenuating tumors is presented along with a discussion regarding the early imaging detection of pancreatic cancers. Colloid (or mucinous non-cystic) pancreatic cancer may resemble a less harmful cystic lesion due to its abundant extracellular mucin, and thus requiring caution in the image interpretation. Serotonin-producing neuroendocrine tumors have recently been recognized as a separate entity from usual neuroendocrine tumors. Exuberant fibrosis caused by serotonin metabolites and scarce tumor cells creates a unique pattern of pancreatic ductal obstruction seen on imaging. Small solid pseudopapillary tumors appear as unencapsulated, completely solid lesions with gradually increasing enhancement after contrast administration, unlike typical solid pseudopapillary neoplasms that present as a large mixed solid and degenerated cystic or hemorrhagic mass encapsulated by a thick capsule and which, therefore, tend to be misdiagnosed on imaging. Solid serous adenoma is a rare, solid variant of serous cystadenoma and appears on imaging as a hypervascular, solid nodule due to its genuinely microscopic cystic, alveolar, and ectatic tubular tumor architecture.

Factors affecting the yield of endoscopic transpapillary bile duct biopsy for the diagnosis of pancreatic head cancer

BACKGROUND

Transpapillary biliary biopsy (TBB) is a simple endoscopic technique that can be performed during an initial biliary drainage session. This procedure has the potential to reduce the load of another tissue sampling in cases of pancreatic head cancer (PHC) with biliary stricture. The aim of this study is to identify factors associated with a positive outcome using TBB for PHC.

METHODS

In total, 130 cases that underwent TBB for investigation of distal biliary stricture were included [62 cases of PHC, 36 cases of distal biliary cancer (DBC), and 32 cases of benign biliary stricture (BBS)]. Factors affecting the diagnostic efficiency of TBB were determined using univariate and multivariate logistic analyses.

RESULTS

Cancer tissue was obtained in 31 cases (50%) of PHC and 33 cases (91.7%) of DBC. Multivariable analysis showed that ≧10 mg/dl of serum bilirubin level (odds ratio [OR]: 5.58; 95% confidence interval [CI]: 1.29-28.20; P = 0.021) and ≧3 tissue samplings (OR: 3.59; 95% CI: 1.02-14.27, P = 0.046) were independent factors affecting cancer-positive rate in cases of PHC. In >90% of resected cases of PHC, cancer involved the left side of the biliary mucosa and the range of cancer invasion (≧2/3 of circumference of biliary mucosa) was also a significant factor (P = 0.001).

CONCLUSIONS

PHC showing high level of serum bilirubin (>10 mg/dl) and high circumferential proportion of bile duct invasion (>2/3 judging from MDCT) is a good indication for biliary biopsy. Targeting the left-side wall and ≧3 tissue samplings will lead to the higher sensitivity.

Surgically proved visually isoattenuating pancreatic adenocarcinoma undetected in both dynamic CT and MRI. Was blind pancreaticoduodenectomy justified?

INTRODUCTION

Visually isoattenuating pancreatic adenocarcinoma is defined as a mass not directly visible on CT and recognizable only by secondary imaging signs. The frequency of isoattenuating pancreatic adenocarcinomas at dynamic-enhanced CT has been reported to range from 5.4% to 14%. Furthermore, 80% of the visually isoattenuating pancreatic adenocarcinomas are detectable in dynamic-enhanced MRI. Consequently, a pancreatic adenocarcinoma undetected in both the above imaging studies is an exceptionally rare event.

PRESENTATION OF CASE

The present report describes a case of a histologically proved 3.5cm pancreatic adenocarcinoma undetected in both dynamic-enhanced CT and MRI. The patient presented with progressive jaundice over the preceding 20 days. Initial abdominal CT showed a dilated pancreatic and common bile duct without demonstration of a lesion responsible for the clinical and imaging findings. Additional diagnostic work-up with dynamic CT and dynamic MRI failed to reveal a definitive mass. ERCP revealed an irregular interruption of the pancreatic and distal common bile duct with upstream dilation. Blind radical pancreaticoduodenectomy was performed. Histologic examination showed a pT3pN1MO pancreatic ductal adenocarcinoma of the head/neck.

DISCUSSION

Isoattenuating pancreatic adenocarcinoma patients represent a small but meaningful subset of patients with pancreatic cancer, as they have better survival. The more favorable postsurgical survival makes it even more imperative to correctly diagnose their cases at early stages by obtaining further diagnostic work-up with dynamic pancreatic CT, dynamic MRI and endoscopic ultrasound.

CONCLUSION

When the above studies fail to unmask the lesion, blind pancreaticoduodenectomy should be based on strong clinical suspicion and secondary imaging findings.

Incidentally discovered solid pancreatic masses: imaging and clinical observations

PURPOSE

The purpose of this study was to review the CT findings and clinical outcome in patients with incidentally discovered solid pancreatic masses.

MATERIALS AND METHODS

Over an 8-year period, from 2001 to 2009, we identified 24 patients with solid pancreatic masses incidentally detected by CT. There were 13 females and 11 males, with a mean age of 67 years. We determined the indication for initial CT, analyzed the CT features, and ascertained the clinical follow-up in all the patients.

RESULTS

All of the solid masses were malignant. There were 14 adenocarcinomas and 10 neuroendocrine tumors. The most common indications for the initial CT were surveillance of an extrapancreatic malignancy (n = 10) and evaluation for hematuria (n = 6). On the initial CT, 16 of the patients (67%) had a clearly visible pancreatic mass. In eight patients isoattenuating masses were identified, only recognized by subtle signs including unexplained dilatation of the pancreatic duct (n = 5) or minimal contour deformity or density of the pancreas (n = 3). The mean survival time for the patients with adenocarcinoma was 21.6 months, and 42 months for the patients with neuroendocrine tumors.

CONCLUSION

Although uncommon, incidentally discovered solid pancreatic masses are malignant neoplasms, either ductal adenocarcinomas or neuroendocrine tumors. Unlike incidentally discovered small cystic lesions, solid pancreatic lesions are often biologically aggressive.