Approach to cystic lesions of the pancreas

ACR Appropriateness Criteria® Pancreatic Cyst

Incidental pancreatic cysts are increasingly detected on imaging studies performed for unrelated indications and may be incompletely characterized on these studies. Adequate morphological characterization is critical due to the small risk of malignant degeneration associated with neoplastic pancreatic cysts, as well as the risk of associated pancreatic adenocarcinoma. For all pancreatic cysts, both size and morphology determine management. Specifically, imaging detection of features, such as pancreatic ductal communication and presence or absence of worrisome features or high-risk stigmata, have important management implications. The recommendations in this publication determine the appropriate initial imaging study to further evaluate a pancreatic cyst that was incidentally detected on a nondedicated imaging study. The recommendations are designed to maximize the yield of diagnostic information in order to better risk-stratify pancreatic cysts and assist in guiding future management. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Pancreatic mucinous cystic neoplasms: a clinicopathological study of 11 cases and detailed review of literature

Background

Mucinous cystic neoplasms (MCNs) of pancreas are relatively rare, occur almost exclusively in middle-aged females, and are overwhelmingly located in the body and tail of the pancreas, histologically show an ovarian type stroma. MCNs are premalignant, low aggressive tumors. Here we describe the clinicopathologic and radiologic features and follow up of cases diagnosed in our practice. We also present a detailed review of recent literature.

Materials and methods

Based on strict criteria, 11 cases diagnosed between 2002 and 2016 were included in the study.

Results

All cases were reviewed histologically. Mean and median age was 46.7 and 46 years respectively. All patients were females and 9 out of 11 cases were located in the body and/or tail of the pancreas. Mean tumor size was 8 cm. Grossly, cysts were uni or multilocular and ranged from a few millimeters to several centimeters in diameter. Microscopically, all cases showed characteristic tall columnar, mucin producing epithelium and ovarian type stroma. Atypia was mild in 8 cases and severe in 3 cases. The latter 3 cases were classified as non-invasive MCNs with high grade dysplasia (2 cases) and MCN with an associated invasive carcinoma (1 case). On immunohistochemistry, all cases showed epithelial positivity for cytokeratin AE1/AE3 and stromal positivity for vimentin and smooth muscle actin. Follow up was available in 7 cases. All patients were alive and well with no recurrence.

Conclusions

Our cases show features similar to those described in other published studies although cases in our series tended to be larger in number. Since these tumors are relatively rare, premalignant and have strict diagnostic criteria, they must always be considered in the differential diagnosis of pancreatic mucinous cystic lesions. Larger studies incorporating greater number of patients and more detailed follow up will help in increasing our understanding of MCNs.

Morphological differentiation and follow-up of pancreatic cystic neoplasms using endoscopic ultrasound

Endoscopic ultrasound (EUS) is a key modality for the evaluation of suspected pancreatic cystic neoplasms (PCNs), as the entire pancreatic gland can be demonstrated with high spatial resolution from the stomach and duodenum. Detailed information can be acquired about the internal contents of the cyst(s) [septum, capsule, mural nodules (MNs)], its relation with the main pancreatic duct (MPD), and any parenchymal changes in the underlying gland. PCNs comprise true cysts and pseudocysts. True cysts can be neoplastic or nonneoplastic. Here, we describe serous cystic neoplasm (SCN), mucinous cystic neoplasm (MCN), and intraductal papillary mucinous neoplasm (IPMN) as prototype neoplastic cysts, along with nonneoplastic lymphoepithelial cysts (LECs).

Incremental value of secretin-enhanced magnetic resonance cholangiopancreatography in detecting ductal communication in a population with high prevalence of small pancreatic cysts

PURPOSE

We investigated the incremental diagnostic yield of S-MRCP in a population with high prevalence of small pancreatic cysts.

METHODS

Standard MRCP protocol was performed with and without secretin using 1.5 T units in subjects undergoing pancreatic screening because of a strong family history of pancreatic cancer as part of the multicenter Cancer of the Pancreas Screening-3 trial (CAPS 3). All studies were reviewed prospectively by two independent readers who recorded the presence and number of pancreatic cysts, the presence of visualized ductal communication before and after secretin, and the degree of confidence in the diagnoses.

RESULT

Of 202 individuals enrolled (mean age 56 years, 46% males), 93 (46%) had pancreatic cysts detected by MRCP, and 64 of the 93 had pre-and post-secretin MRCP images available for comparison. Data from the 128 readings show that 6 (6/128=4.7%) had ductal communication visualized only on the secretin studies compared to pre-secretin studies (odds ratio 1.28, p=0.04). In addition, there was a statistically significant increase in confidence in reporting ductal communication after secretin compared to before secretin (p<0.0005).

CONCLUSION

At 1.5 T MRI, the use of secretin can improve the visualization of ductal communication of cystic pancreatic lesions.

Pancreatic cystic lesions: The value of contrast-enhanced endoscopic ultrasound to influence the clinical pathway

BACKGROUND AND OBJECTIVES

Cystic pancreatic lesions are a growing diagnostic challenge. The aim of this study was to proof a new diagnostic concept based on contrast-enhanced endoscopic ultrasound (CE-EUS) for differential diagnosis.

PATIENTS AND METHODS

A total of 125 patients with unclear cystic pancreatic lesions were included. The initial diagnostic was made by CE-EUS dividing the lesions in a group without contrast enhancing effect in the cystic wall, septae or nodule indicating pseudocysts or dysontogenetic cysts and a group with contrast enhancing effect in the described structures indicating cystic neoplasias. The investigations were performed using a Pentax echoendoscope and Hitachi Preirus ultrasound machine. The contrast enhancer used was 4.8 mL SonoVue(®) (Bracco, Italy). The group with suspected cystic neoplasia was referred for endoscopic fine-needle puncture for further diagnostic or treatment decisions.

RESULTS

The dividing of the groups by contrast-enhanced ultrasound was feasible because all (n = 56) suspected cystic neoplasias showed a contrast enhancing effect, whereas in only 4 from 69 pseudocystic or dysontogenetic cystic lesions a contrast enhancing effect in the wall could be observed. Endoscopic fine-needle puncture could diagnose all malignant neoplasias and relevant premalignant conditions. The long-term follow-up did not show any development of malignant cystic lesions.

CONCLUSION

Using CE-EUS and endoscopic fine-needle puncture as diagnostic criteria seemed to be a feasible method to deal with different cystic lesions in daily practice.