Intraductal papillary mucinous neoplasms of the pancreas: a clinical challenge

Intraductal papillary mucinous neoplasm originating from a jejunal heterotopic pancreas: A case report

BACKGROUND

Intraductal papillary mucinous neoplasm (IPMN) is a rare pancreatic tumor and has the potential to become malignant. Surgery is the most effective treatment at present, but there is no consensus on the site of resection. Heterotopic pancreas occurs in the gastrointestinal tract, especially the stomach and duodenum but is asymptomatic and rare. We report a case of ectopic pancreas with IPMN located in the jejunum.

CASE SUMMARY

A 56-year-old male patient suffered from severe pain, nausea and vomiting due to a traffic accident and sought emergency treatment at our hospital. Contrast-enhanced computed tomography of the whole abdomen suggested splenic congestion, which was considered to be splenic rupture. Emergency laparotomy was performed, and the ruptured spleen was removed during the operation. Unexpectedly, a cauliflower-like mass of about 2.5 cm × 2.5 cm in size was incidentally found about 80 cm from the ligament of Treitz during the operation. A partial small bowel resection was performed, and postoperative pathology confirmed the small bowel mass as heterotopic pancreas with low-grade IPMN.

CONCLUSION

Ectopic pancreas occurs in the jejunum and is pathologically confirmed as IPMN after surgical resection.

Granular cell tumour of the pancreas: a case report and systematic review

PURPOSE

Granular cell tumours (GCTs) of the pancreas are mostly benign and exceptionally rare, with no unique identifying radiological features. Following a case discussion of a patient with GCT, a comprehensive review of available literature was conducted to identify the common diagnostic features associated with GCT.

METHODS

Following a case report identified in our institution, a systematic review was conducted by two authors in accordance with Preferred Reporting Items for Systematic review and Meta-Analysis protocols (PRISMA) guidelines. Databases MEDLINE, EMBASE, Scopus, World of Science, and grey literature were searched on August 2021. Inclusion criteria were histopathology diagnosed granular cell tumour of the pancreas.

RESULTS

A 37-year-old male presented with 1 month of abdominal pain and an MRI demonstrating a dilated main pancreatic duct, distal parenchymal atrophy, but no focal lesion. Repeat MRI at 6 months re-demonstrated similar findings and subsequent endoscopic ultrasound was suspicious for main duct IPMN. Following multidisciplinary team discussion, a spleen-preserving distal pancreatectomy was performed. Histopathology demonstrated granular cell tumour with cells diffusely positive for S100 and no malignant transformation. 11 case reports were identified in the literature with diagnosis confirmed on tissue histopathology based on positive immunohistochemical staining for S-100 protein. Eight patients presented with gastrointestinal symptoms with abdominal pain the main presenting complaint (50%). 10 patients underwent CT with portal venous contrast and all underwent endoscopic examination. Imaging findings were similar in five studies for EUS which demonstrated a hypoechoic lesion with homogenous appearance. On non-contrast CT GCT was iso-enhancing, and with portal venous contrast demonstrated hypo-enhancement that gradually enhanced on late phases. Pre-operative diagnosis of pancreatic carcinoma was described in six cases based on imaging and biopsy, resulting in progression to surgical resection. Nine patients were managed surgically and no complications identified on follow-up (6-52 months).

CONCLUSION

The currently proposed management pathway includes EUS with biopsy and CT, and surgical resection recommended due to malignancy risk. Improved sample collection with EUS-FNA and microscopic assessment utilising S-100 immunohistochemistry may improve pre-operative diagnosis. Limitations include rare numbers in reported literature and short follow-up not allowing an assessment of GCT's natural history and malignancy risk. Additional cases would expand the current dataset of GCTs of the pancreas, so that surgical resection may be avoided in the future.

Comparison of utility of deep learning reconstruction on 3D MRCPs obtained with three different k-space data acquisitions in patients with IPMN

OBJECTIVE

To compare the utility of deep learning reconstruction (DLR) for improving acquisition time, image quality, and intraductal papillary mucinous neoplasm (IPMN) evaluation for 3D MRCP obtained with parallel imaging (PI), multiple k-space data acquisition for each repetition time (TR) technique (Fast 3D mode multiple: Fast 3Dm) and compressed sensing (CS) with PI.

MATERIALS AND METHODS

A total of 32 IPMN patients who had undergone 3D MRCPs obtained with PI, Fast 3Dm, and CS with PI and reconstructed with and without DLR were retrospectively included in this study. Acquisition time, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) obtained with all protocols were compared using Tukey's HSD test. Results of endoscopic ultrasound, ERCP, surgery, or pathological examination were determined as standard reference, and distribution classifications were compared among all 3D MRCP protocols by McNemar's test.

RESULTS

Acquisition times of Fast 3Dm and CS with PI with and without DLR were significantly shorter than those of PI with and without DLR (p < 0.05). Each MRCP sequence with DLR showed significantly higher SNRs and CNRs than those without DLR (p < 0.05). IPMN distribution accuracy of PI with and without DLR and Fast 3Dm with DLR was significantly higher than that of Fast 3Dm without DLR and CS with PI without DLR (p < 0.05).

CONCLUSION

DLR is useful for improving image quality and IPMN evaluation capability on 3D MRCP obtained with PI, Fast 3Dm, or CS with PI. Moreover, Fast 3Dm and CS with PI may play as substitution to PI for MRCP in patients with IPMN.

KEY POINTS

• Mean examination times of multiple k-space data acquisitions for each TR and compressed sensing with parallel imaging were significantly shorter than that of parallel imaging (p < 0.0001). • When comparing image quality of 3D MRCPs with and without deep learning reconstruction, deep learning reconstruction significantly improved signal-to-noise ratio and contrast-to-noise ratio (p < 0.05). • IPMN distribution accuracies of parallel imaging with and without deep learning reconstruction (with vs. without: 88.0% vs. 88.0%) and multiple k-space data acquisitions for each TR with deep learning reconstruction (86.0%) were significantly higher than those of others (p < 0.05).

Abbreviated Magnetic Resonance Imaging With Breath-Hold Three-Dimensional Magnetic Resonance Cholangiopancreatography: Assessment of Malignant Risk of Pancreatic Intraductal Papillary Mucinous Neoplasm

BACKGROUND

For surveillance of pancreatic intraductal papillary mucinous neoplasms (IPMNs), magnetic resonance imaging (MRI)/magnetic resonance cholangiopancreatography (MRCP) is preferred over computed tomography, but the long acquisition time limits its use.

PURPOSE

To investigate the diagnostic performance of abbreviated MRI with breath-hold (BH) three-dimensional MRCP (abbreviated MRI-BH) for malignant risk assessment of pancreatic IPMN.

STUDY TYPE

Retrospective.

POPULATION

Two hundred and thirty-five patients with IPMNs (M:F = 115:120; mean age ± SD, 66 ± 9 years; typical imaging features with ≥2-year stability [N = 172] and histopathologically confirmed [N = 63]).

FIELD STRENGTH/SEQUENCE

3.0 T/ abbreviated MRI-BH (single-shot fast spin-echo, T1W fat-suppressed gradient-echo sequence, and BH-3D-MRCP).

ASSESSMENT

Abbreviated MRI-BH was reviewed by three reviewers, and its diagnostic performance was assessed using the predetermined scoring system. The diagnostic performance for the mural nodule detection was assessed. Additionally, diagnostic performance of abbreviated MRI was compared with that of full-sequence MRI.

STATISTICAL TESTS

Area under the receiver operating characteristic curve (AUC) with z-test, and linear-weighted kappa values.

RESULTS

Thirty-five patients had malignant IPMN. At a cut-off score ≥3, AUCs of abbreviated MRI-BH for detecting malignant IPMN were 0.959 for reviewer 1, 0.962 for reviewer 2, and 0.956 for reviewer 3. The sensitivity of reviewers 1, 2, and 3 was 97.1% for all, and the specificity was 85.5%, 86.0%, and 85.0%, respectively. Regarding mural nodule detection (N = 22), abbreviated MRI-BH demonstrated a sensitivity of 95.5% and a specificity of 88.3% for reviewer 1, a sensitivity of 86.4% and a specificity of 92.0% for reviewer 2, and a sensitivity of 86.4% and a specificity of 89.2% for reviewer 3. There were no significant differences between AUC of abbreviated MRI-BH and that of full-sequence MRI in the three reviewers (P > 0.05).

DATA CONCLUSION

Abbreviated MRI-BH showed good diagnostic performance for detecting malignant IPMNs by using a predetermined scoring system.

LEVEL OF EVIDENCE

3 TECHNICAL EFFICACY STAGE: 2.

Nomogram for the Prediction of High-Grade Dysplasia and Invasive Carcinoma in Patients With Intraductal Papillary Mucinous Neoplasms of the Pancreas Based on Variables of Noninvasive Examination

Intraductal papillary mucinous neoplasms (IPMNs) are a heterogeneous group of neoplasms and represent the most common identifiable precursor lesions of pancreatic cancer. Clinical decision-making of the risk for malignant disease, including high-grade dysplasia and invasive carcinoma, is challenging. Moreover, discordance on the indication for resection exists between the contemporary guidelines. Furthermore, most of the current nomogram models for predicting malignant disease depend on endoscopic ultrasonography to evaluate the precise size of mural nodules. Thus, this study aimed to propose a model to predict malignant disease using variables from a noninvasive examination. We evaluated patients who underwent resection of pathologically confirmed IPMNs between November 2010 and December 2018 and had preoperative clinical data available for review. Based on binary multivariable logistic regression analysis, we devised a nomogram model to predict malignant IPMNs. The area under the receiver operating characteristics curve (AUC) was used to evaluate the discrimination power of the model. Of the 333 patients who underwent resection of IPMNs, 198 (59.5%) had benign and 135 (40.5%) had malignant IPMNs. Multivariable logistic regression analysis showed that cyst size, cyst location, cyst wall enhancement, multicystic lesion, diameter of main pancreatic duct, neutrophil-to-lymphocyte ratio, serum carbohydrate antigen 19-9, and carcinoembryonic antigen were significantly associated with malignancy. The nomogram, constructed based on these variables, showed excellent discrimination power with an AUC of 0.859 (95% CI: 0.818–0.900, P < 0.001). In conclusion, we have developed a nomogram consisting of a combination of cross-sectional imaging features and blood markers, variables that can readily be obtained by noninvasive examinations during the surveillance period, which can distinguish benign from malignant IPMNs. Nevertheless, external validation is warranted.

Intraductal papillary mucinous neoplasm of the pancreas: diagnostic performance of the 2017 international consensus guidelines using CT and MRI

OBJECTIVES

To assess the diagnostic performance of the 2017 international consensus guidelines for intraductal papillary mucinous neoplasm (IPMN) of the pancreas and to compare the diagnostic performance and intermodality agreement between contrast-enhanced CT and MRI.

METHODS

We retrospectively evaluated patients with surgical resection of IPMN of the pancreas who underwent preoperative CT and MRI between 2009 and 2019. Two radiologists evaluated the clinical and imaging features of IPMN of pancreas according to the 2017 international consensus guideline. Univariable and multivariable analyses were performed to identify significant predictors of malignancy in IPMN. The diagnostic abilities of CT and MRI were compared, and their intermodality agreement was determined.

RESULTS

Of 175 patients (mean age, 64 years; 116 males), 88 (50.3%) had malignant IPMN. On multivariable analysis, all three high-risk stigmata (main pancreatic duct [MPD] ≥ 10 mm, mural nodule ≥ 5 mm, and obstructive jaundice) and two worrisome features (MPD 5-9 mm and elevated carbohydrate antigen 19-9) were associated with malignant IPMN on CT and MRI (p < 0.05). A mural nodule < 5 mm on MRI was also associated with malignant IPMN (OR 5.3, p = 0.009). The diagnostic accuracy of high-risk stigmata showed no difference between CT and MRI (73.7% vs. 75.4%, p = 0.505), with good to excellent intermodality agreement.

CONCLUSIONS

Current high-risk stigmata had the strongest association with malignant IPMN on CT and MRI. Although MRI is superior to CT for identifying mural nodules, diagnostic performance for differentiating malignant from benign IPMNs was similar between CT and MRI.

KEY POINTS

• The current high-risk stigmata in the 2017 International Consensus Guidelines had the strongest association with malignant IPMN on CT and MRI. • MRI is better than CT for identifying enhancing mural nodule. • Diagnostic performance for differentiating malignant from benign IPMNs was similar between CT and MRI.

Fibrous Dysplasia/McCune-Albright Syndrome: A Rare, Mosaic Disease of Gα s Activation

Fibrous dysplasia/McCune-Albright syndrome (FD/MAS) is a rare disorder of striking complexity. It arises from somatic, gain-of-function mutations in GNAS, leading to mosaic Gα s activation and inappropriate production of intracellular cyclic adenosine monophosphate (cAMP). The clinical phenotype is largely determined by the location and extent of affected tissues, and the pathophysiological effects of Gα s activation within these tissues. In bone, Gα s activation results in impaired differentiation of skeletal stem cells, leading to discrete skeletal lesions prone to fracture, deformity, and pain. Extraskeletal manifestations include a variable combination of hyperpigmented macules and hyperfunctioning endocrinopathies. Distinctive age-related changes in disease development has key effects on histologic, radiographic, and clinical features. FD/MAS thus presents along a uniquely broad clinical spectrum, and the resulting challenges in diagnosis and management can be difficult for clinicians. This review presents FD/MAS in the context of a mosaic disorder of Gα s activation, providing an intellectual framework within which to understand, evaluate, and treat this interesting disease. It includes a comprehensive summary of current understanding of FD/MAS pathogenesis, and a detailed discussion of clinical presentation and management. Critical areas of unmet need are highlighted, including discussion of key challenges and potential solutions to advance research and clinical care in FD/MAS.

Enucleation for branch duct intraductal papillary mucinous neoplasms: a systematic review and meta-analysis

BACKGROUND

The role of enucleation (EN) for branch duct intraductal papillary mucinous neoplasms (BD-IPMN) is poorly defined. This systematic review aims to review EN for BD-IPMN and compare it with pancreatic resection (pancreaticoduodenectomy, distal pancreatectomy and central pancreatectomy).

METHODS

A systematic review of published literature was performed using PRISMA guidelines, and included a search of PubMed, MEDLINE and SCOPUS databases.

RESULTS

Sixteen studies were included in the final analysis comprising 991 patients with 293 EN patients and 698 resected patients. EN was most often performed for low grade (77%, 151/197) BD-IPMN's (99%, 251/253) of the pancreatic head (64%, 106/165), with a pooled mean diameter of 21 mm (SD 28 mm). EN was a shorter procedure (MD -115.8 min, CI -142.2 to -89.5 min, P=<0.001) with a lower rate of post-pancreatectomy haemorrhage (EN 1% 2/144, Resection 5% 10/186, RR 0.32, CI 0.11 to 0.94, P = 0.043) and postoperative exocrine and endocrine insufficiency (P = <0.001 and P = 0.003 respectively) than resection.

CONCLUSION

EN for BD-IPMN's appears to be a reasonable alternative to resection in low risk BD-IPMN's, allowing preservation of exocrine and endocrine function with comparable reoperation and recurrence rates to resection. However, surveillance was indicated in these low risk patients based on current published guidelines.

The Clinical Spectrum of McCune-Albright Syndrome and Its Management

McCune-Albright syndrome (MAS) is a rare, mosaic disorder presenting along a broad clinical spectrum. Disease arises from somatic-activating GNAS mutations, leading to constitutive Gαs activation and ligand-independent signaling of the Gαs-coupled protein receptor. The phenotype is largely determined by location and extent of tissues in which the GNAS mutation is expressed, as well as the pathophysiologic effects of Gαs activation within these tissues. Patients pre-sent clinically with a variable combination of fibrous dysplasia of bone (FD), café-au-lait skin macules, and hyperfunctioning endocrinopathies. In bone, Gαs leads to impaired differentiation of skeletal stem cells and formation of discrete, expansile FD lesions, resulting in fractures, pain, and functional impairment. A systematic approach to diagnosis and management is critically important to optimize outcomes for patients with FD/MAS. There are no medical therapies capable of altering the disease course in FD; however, screening and treatment for endocrinopathies can mitigate some skeletal morbidities. This review summarizes current understanding of MAS pathophysiology, describes the spectrum of clinical features, and includes a detailed discussion of the recommended approach to diagnosis and management.

Diagnosis and management of intraductal papillary mucinous neoplasms of the pancreas

Background and aim of the work: Intraductal papillary mucinous neoplasms (IPMN) of the pancreas are cystic lesions with malignant potential. Given their increasing incidence in the latest years, a precise characterization and management of these lesions have become more and more crucial: even though the majority of IPMN has a benign and indolent course, it is fundamental to early recognize and stratify patients in order to accurately plan a tailored follow-up and to individuate those that would benefit of surgical treatment. The aim of this paper is to highlight the most recent evidence on IPMN available in the current literature. Methods: We performed a review of the recent literature and of the recent guidelines about pancreatic cystic lesions, especially IPMN. Results: The incidence of IPMN is now on the rise: an increasing number of patients, possibly because of the increasing diagnostic yield of imaging techniques, is being diagnosed with pancreatic cystic lesions, a great part of which are IPMN. The possibility of malignant transformation requires a careful approach to these patients, in the need of tailoring the follow-up and the therapy. Conclusion: A detailed diagnosis, the determination of risk factors for malignant transformation and a multisciplinary approach are of foremost importance for an effective management of IPMN. (www.actabiomedica.it)