Pancreatic endocrine tumours: mutational and immunohistochemical survey of protein kinases reveals alterations in targetable kinases in cancer cell lines and rare primaries

BACKGROUND

Kinases represent potential therapeutic targets in pancreatic endocrine tumours (PETs).

PATIENTS AND METHODS

Thirty-five kinase genes were sequenced in 36 primary PETs and three PET cell lines: (i) 4 receptor tyrosine kinases (RTK), epithelial growth factor receptor (EGFR), human epidermal growth factor receptor 2 (HER2), tyrosine-protein kinase KIT (KIT), platelet-derived growth factor receptor alpha (PDGFRalpha); (ii) 6 belonging to the Akt/mTOR pathway; and (iii) 25 frequently mutated in cancers. The immunohistochemical expression of the four RTKs and the copy number of EGFR and HER2 were assessed in 140 PETs.

RESULTS

Somatic mutations were found in KIT in one and ATM in two primary neoplasms. Among 140 PETs, EGFR was immunopositive in 18 (13%), HER2 in 3 (2%), KIT in 16 (11%), and PDGFRalpha in 135 (96%). HER2 amplification was found in 2/130 (1.5%) PETs. KIT membrane immunostaining was significantly associated with tumour aggressiveness and shorter patient survival. PET cell lines QGP1, CM and BON harboured mutations in FGFR3, FLT1/VEGFR1 and PIK3CA, respectively.

CONCLUSIONS

Only rare PET cases, harbouring either HER2 amplification or KIT mutation, might benefit from targeted drugs. KIT membrane expression deserves further attention as a prognostic marker. ATM mutation is involved in a proportion of PET. The finding of specific mutations in PET cell lines renders these models useful for preclinical studies involving pathway-specific therapies.

Pseudopapillary tumor in pediatric age: clinical and surgical management

BACKGROUND

Solid pseudopapillary tumors of the pancreas are rare exocrine pancreatic tumors. Through a review of pediatric cases in a single Institution, we present the clinical and surgical management of this neoplasm.

METHODS

We retrospectively reviewed the clinical charts of patients treated at our unit between 1995 and 2009 for SPT. Clinical and surgical management were analyzed and reported.

RESULTS

During the study period 11 patients underwent surgery for pseudopapillary tumor. Five patients were treated with duodenum-preserving pancreatic head resection and six patients with splenopancreasectomy with a Roux-en-Y pancreatic jejunostomy. Patients did not show recurrence and are currently disease free. Blood tests, Ultrasound, Computed tomography and Magnetic Resonance Imaging were not useful to preoperatively identify the nature of the pancreatic masses.

CONCLUSION

Solid pseudopapillary tumor is a rare condition that should be taken into account for the differential diagnosis of pancreatic masses in pediatric age. Due to its favourable prognosis, surgical removal should be planned and done following the intraoperative findings.

Surgical treatment of pancreatic tumors in childhood and adolescence: uncommon neoplasms with favorable outcome

BACKGROUND/AIMS

Pancreatic tumors in children and adolescents are uncommon. The aim of the present paper was to analyze short- and long-term outcomes after surgical treatment of primary pancreatic neoplasms in children and adolescents at a single high-volume center for pancreatic diseases.

METHODS

Retrospective review of medical records and pathology reports of patients younger than 18 years who underwent surgery at Verona University Hospital from 1990 through 2010.

RESULTS

The study population consisted of 20 patients. Abdominal pain and palpable mass were the most common presenting symptoms. No patient had a locally advanced, unresectable or metastatic disease. Complete resection (R0) was achieved in 19 patients. There was no postoperative mortality, but postoperative complications occurred in 5 cases (25%). Histological examination showed 12 solid pseudopapillary tumors, 5 neuroendocrine tumors, 2 cystadenomas and 1 epithelial malignant tumor. At a median follow-up of 49.5 months (range: 7-234), there was no tumor recurrence. Postoperative diabetes was diagnosed in 1 patient and 4 other patients developed pancreatic exocrine insufficiency.

CONCLUSION

In the setting of a high-volume surgical center, radical resection of pancreatic tumors in children and adolescents is associated with acceptable postoperative morbidity and favorable long-term outcome.

Tumor size correlates with malignancy in nonfunctioning pancreatic endocrine tumor

BACKGROUND

Tumor size is a criterion of staging in nonfunctioning pancreatic endocrine tumors as well as a predictor of outcome after curative resection. This study analyzes the correlation between tumor size and malignancy in patients with nonfunctioning pancreatic endocrine tumors.

METHODS

All patients with nonfunctioning pancreatic endocrine tumors who underwent curative resection (R0) at our institution between 1990 and 2008 were considered. Their clinicopathologic characteristics were compared among 3 different groups according to tumor size. Univariate and multivariable analyses were performed.

RESULTS

Over the study period, 177 patients were identified. Overall, 90 patients (51%) had a tumor size ≤2 cm (group 1), 46 (26%) had tumor size between >2 cm and ≤4 cm (group 2), and 41 (23%) had tumor size >4 cm (group 3). Tumors ≤2 cm were more frequently incidentally discovered (group 1, 57% vs group 2, 51% vs group 3, 32%; P = .014) and benign (group 1, 81% vs group 2, 65% vs group 3, 5%; P < .0001). The presence of a nonfunctioning pancreatic endocrine tumor >2 cm and a nonincidental diagnosis of the tumor were independent predictors of malignancy at multivariable analysis. None of the 51 patients (29%) with a pancreatic endocrine tumor ≤2 cm that was incidentally diagnosed died of disease.

CONCLUSION

A strict correlation between tumor size and malignancy in nonfunctioning pancreatic endocrine tumors was demonstrated. A nonoperative management could be advocated for tumors ≤2 cm when discovered incidentally.

Outcomes after resection of locally advanced or borderline resectable pancreatic cancer after neoadjuvant therapy

BACKGROUND

Neoadjuvant treatment frequently is performed in unresectable/borderline resectable pancreatic cancer. The aim of this study was to retrospectively compare postoperative outcomes and survival of patients who underwent pancreatectomy after neoadjuvant treatment for locally advanced/borderline resectable pancreatic cancer (neoadjuvant treatment group) with those of patients with resectable disease who underwent upfront surgery.

METHODS

Between 2000 and 2008, there were 403 patients who underwent pancreatic cancer resection, 41 (10.1%) patients after neoadjuvant treatment for initially unresectable tumors and 362 (89.9%) patients had upfront surgery. Univariate and multivariable analyses were performed.

RESULTS

Mortality/morbidity rates were similar in the 2 groups. Nodal metastases were significantly lower in the neoadjuvant treatment group (31.7% vs 86.2%; P < .001). A complete pathologic response was observed in 13.6% after neoadjuvant treatment. Median disease-specific survival from resection was 35 and 27 months in the neoadjuvant treatment and upfront groups, respectively (P = .74). In the neoadjuvant treatment group survival rates were similar in N0/N1 patients.

CONCLUSIONS

Postoperative mortality and morbidity do not significantly increase after neoadjuvant treatment. Neoadjuvant treatment in locally advanced pancreatic cancer can lead to an objective pathologic response, but this does not significantly improve survival after resection.

Mucinous cystic neoplasms of the liver: a clinicopathological study and comparison with intraductal papillary neoplasms of the bile duct

Mucinous cystic neoplasm of the liver has been a controversial entity, in particular, regarding differentiation from intraductal papillary neoplasm of the bile duct. In this study, we compared the characteristics of hepatic mucinous cystic neoplasms with ovarian-like stroma (n=29) to those of cyst-forming intraductal papillary neoplasms of the bile duct (n=12). Radiological or macroscopic appearance, histological grade of malignancy, and postoperative clinical course were recorded. Immunohistochemistry for biliary or gastrointestinal markers was performed to characterize cell phenotypes. The patients with hepatic mucinous cystic neoplasm were all female and ranged in age from 21 to 67 years, which was significantly younger than that in the patients with biliary intraductal papillary neoplasm. Eighteen mucinous cystic neoplasms (76%) were located in the left lobe, with 13 (54%) in segment IV. Mucinous cystic neoplasms were significantly larger than intraductal papillary neoplasms (median diameter: 110 vs 50 mm, P=0.008). In contrast to intraductal papillary neoplasms that were all histologically malignant, 26 mucinous cystic neoplasms (90%) were adenomas, 2 (7%) were borderline malignant, and 1 (3%) was a carcinoma in situ. Benign mucinous cystadenomas had the pure biliary immunophenotype, whereas gastrointestinal markers including cytokeratin 20 and mucin core proteins 2, 5AC, and 6 were more frequently expressed in borderline or malignant mucinous cystic neoplasms and biliary intraductal papillary neoplasms. There was no mortality in the patients with mucinous cystic neoplasm, whereas one patient with intraductal papillary neoplasm died of cancer. In conclusion, hepatic mucinous cystic neoplasms and biliary intraductal papillary neoplasms have different clinicopathological characteristics as evidenced by differences in the age and gender of patients, macroscopic appearance, immunophenotypes, and grades of malignancy.

Increased risk for non-autoimmune hypothyroidism in young patients with congenital heart defects

CONTEXT

Newborns with congenital hypothyroidism (CH) have an increased risk for congenital heart defects (CHD) due to a common embryonic developmental program between thyroid gland and heart and great vessels.

OBJECTIVE

Our objective was to investigate the prevalence and origin of thyroid disorders in young patients with CHD.

DESIGN AND SETTING

We conducted a prospective observational study between January 2007 and January 2009 in academic Pediatric Cardiosurgery and Endocrinology.

PATIENTS

Patients included 324 children (164 males, 160 females, aged 0.2-15.4 yrs) with CHD.

INTERVENTION

Subjects underwent hormonal and genetic screening.

MAIN OUTCOME MEASURES

Serum TSH and thyroid hormone levels were assessed.

RESULTS

Two CHD patients were diagnosed with CH at the neonatal screening (1:162). Mild hypothyroidism (serum TSH > 4.0 μU/ml) was diagnosed and confirmed 6 months later [TSH = 5.4 ± 1.5 μU/ml; free T(4) = 1.3 ± 0.2 ng/dl (normal values 0.8-1.9)] in 37 children (11.5%) who were negative at neonatal screening. Hypothyroidism was not related to type of CHD, whereas TSH levels positively correlated with serum N-terminal pro-type B natriuretic peptide levels. Biochemical and ultrasound findings consistent with thyroid autoimmunity were present in three of 37 hypothyroid children (8.1%). One patient had hemiagenesis (2.7%). Variations in candidate genes were screened in CHD patients. NKX2.5 coding sequence was normal in all samples. A 3-Mb microdeletion in 22q11.2 was detected in three patients (8.3%), whereas only known polymorphisms were identified in TBX1 coding sequence.

CONCLUSIONS

CHD patients have an increased risk for both CH (10-fold higher) and acquired mild hypothyroidism (3-fold higher). Unrecognized mild hypothyroidism may negatively affect the outcome of CHD children, suggesting that thyroid function should be repeatedly checked. Thyroid autoimmunity and 22q11.2 microdeletions account for small percentages of these cases, and still unknown mechanisms underline such a strong association.

Splenic artery invasion in pancreatic adenocarcinoma of the body and tail: a novel prognostic parameter for patient selection

BACKGROUND

The value of splenic vessels invasion (which identified T3 tumors) in prognosis after resection for pancreatic ductal adenocarcinoma (PDA) of the body and tail has not been extensively investigated. The goal of this study was to evaluate prognostic factors in PDA of the body/tail, emphasizing the role of splenic vessels infiltration.

METHODS

Between 1990 and 2008, 87 patients who underwent distal pancreatectomy (DP) for histologically proven PDA of the body and tail were analyzed. Clinicopathological prognostic factors for survival were evaluated. Univariate and multivariable analyses were performed.

RESULTS

Postoperative morbidity was 31% with no mortality. The 1-, 3-, and 5-year overall survival rates were 77%, 48%, and 24.5%, respectively. Invasion of the splenic artery (SA) was observed in 19 patients (22%). Patients with SA invasion had a significantly poorer prognosis compared with those without SA invasion (median survival: 15 vs. 39 months, P = 0.014). On multivariable analysis, adjuvant therapy, poor differentiation (G3/G4), R2 resection, the presence of lymph node metastases, and SA invasion were independent predictors of survival.

CONCLUSIONS

Along with other well-known prognostic factors, invasion of SA is an independent predictor of poor survival in PDA of the body/tail. In case of the presence of SA infiltration, neoadjuvant treatment should be considered. SA infiltration might be reclassified from a T3 to T4 tumor.

Deposition of complement C3c, immunoglobulin (Ig)G4 and IgG at the basement membrane of pancreatic ducts and acini in autoimmune pancreatitis

AIMS

Autoimmune pancreatitis (AIP) is a type of pancreatitis whose immunopathogenesis is still unknown. It has been reported that renal biopsy specimens from patients diagnosed with both AIP and tubulointerstitial nephritis reveal deposits containing complement C3, immunoglobulin (Ig)G and IgG4 at the tubular basement membranes (BMs). The aim was to investigate the deposition of complement and immunoglobulins in pancreatic tissue from AIP patients compared to non-AIP patients.

METHODS

Double immunofluorescence microscopy for C3c, IgG4 and IgG together with CK7, trypsin, collagen IV, CD31 and CD79a, as well as immunofluorescence microscopy for C1q, IgA and IgM, were performed on frozen pancreatic tissue from AIP and alcoholic chronic pancreatitis (ACP) patients.

RESULTS

In AIP patients, complement C3c, IgG4 and IgG were deposited at the collagen IV-positive BMs of pancreatic and bile ducts and of acini. In a minority of the ACP patients, weak C3c-positive BM deposits were detected, but no IgG4- or IgG-positive BM deposits were present.

CONCLUSION

The deposition of C3c, IgG4 and IgG at the BM of small- and medium-sized ducts and acini of the pancreas is characteristic of AIP. This suggests that immune complex-mediated destruction of ducts and acini play a role in the pathogenesis of AIP.

Presentation and outcome of pancreaticoduodenal endocrine tumors in multiple endocrine neoplasia type 1 syndrome

AIM

To assess presentation and outcome of pancreaticoduodenal endocrine tumors (PDETs) in a single center series of multiple endocrine neoplasia type 1 (MEN1) patients.

METHODS

Retrospective analysis of prospectively collected data of MEN1 patients observed at the University of Verona.

RESULTS

Thirty-one MEN1 patients had PDETs, including 16 nonfunctioning (NF), 6 insulinomas and 9 Zollinger-Ellison syndrome (ZES). In 16 of these patients (52%), PDET was the manifestation which led to the diagnosis of MEN1; among this group, 15 patients (94%) previously had unidentified primary hyperparathyroidism (PHPT), which was asymptomatic in 9 cases (60%). Of the 31 patients, 19 (61%) underwent curativesurgery and 13 (68%, 7 NF-PDETs, 4 insulinomas and 2 ZES) were disease-free after a median follow-up of 3 years (range: 0.5-15). One patient had debulking surgery with stable disease after 2 years of follow-up. Eight patients with NF-PDETs ≤20 mm and 2 with ZES, treated with a conservative approach, showed stable disease. One patient with insulinoma was lost to follow-up.

CONCLUSIONS

PDET may be the manifestation that leads to MEN1 diagnosis since the almost constant presence of PHPT is very often unrecognized or considered sporadic. Conversely, the presence of PDETs should be looked for in all patients presenting PHPT, even if asymptomatic, particularly before age 50. Surgery may be curative in the majority of insulinomas and can prolong disease-free survival in NF-PDET, but is not proven to be effective in ZES. A conservative approach can be safely reserved for patients with NF-PDETs ≤20 mm.

Chromosome 3p alterations in pancreatic endocrine neoplasia

Pancreatic endocrine tumors (PET) are rare neoplasms classified as functioning (F-PET) or non-functioning (NF-PET) according to the presence of a clinical syndrome due to hormonal hypersecretion. PETs show variable degrees of clinical aggressiveness and loss of chromosome 3p has been suggested to be associated with an advanced stage of disease. We assessed chromosome 3p copy number in 113 primary PETs and 32 metastases by fluorescence in situ hybridization (FISH) using tissue microarrays. The series included 56 well-differentiated endocrine tumors (WDET), 62 well-differentiated endocrine carcinomas (WDEC), and 6 poorly differentiated endocrine carcinomas (PDEC). Chromosome 3p alterations were found in 23/113 (20%) primary tumors, with losses being predominant over gains (14% vs. 6%). Loss of 3p was found in 5/55 (9%) WDET, 11/52 (21%) WDEC, and never in PDEC. Gains of 3p were detected in 4/55 (7%) WDET, no WDEC, but notably in 3/6 (50%) PDEC (OR 23.6; P = 0.003). Metastases were more frequently monosomic for 3p compared to primary tumors (OR 3.6; P = 0.005). Monosomy was significantly associated with larger tumor size, more advanced tumor stage, and metastasis. No association was found with survival. Chromosome 3p copy number alterations are frequent events in advanced stage PET, with gains prevailing in PDEC while losses are more frequent in WDEC, supporting the view that a specific pattern of alterations are involved in these diverse disease subtypes.

MEN1 in pancreatic endocrine tumors: analysis of gene and protein status in 169 sporadic neoplasms reveals alterations in the vast majority of cases

Pancreatic endocrine tumors (PETs) may be part of hereditary multiple endocrine neoplasia type 1 (MEN1) syndrome. While MEN1 gene mutation is the only ascertained genetic anomaly described in PETs, no data exist on the cellular localization of MEN1-encoded protein, menin, in normal pancreas and PETs. A total of 169 PETs were used to assess the i) MEN1 gene mutational status in 100 clinically sporadic PETs by direct DNA sequencing, ii) immunohistochemical expression of menin in normal pancreas and 140 PETs, including 71 cases screened for gene mutations, and iii) correlation of these findings with clinical-pathological parameters. Twenty-seven PETs showed mutations that were somatic in 25 patients and revealed to be germline in 2 patients. Menin immunostaining showed strong nuclear and very faint cytoplasmic signal in normal islet cells, whereas it displayed abnormal location and expression levels in 80% of tumors. PETs harboring MEN1 truncating mutations lacked nuclear protein, and most PETs with MEN1 missense mutations showed a strong cytoplasmic positivity for menin. Menin was also misplaced in a significant number of cases lacking MEN1 mutations. In conclusion, the vast majority of PETs showed qualitative and/or quantitative alterations in menin localization. In 30% of cases, this was associated with MEN1 mutations affecting sequences involved in nuclear localization or protein-protein interaction. In cases lacking MEN1 mutations, the alteration of one of the menin interactors may have prevented its proper localization, as suggested by recent data showing that menin protein shuttles between the nucleus and cytoplasm and also affects the subcellular localization of its interactors.

Resectable pancreatic cancer: who really benefits from resection?

BACKGROUND

The 1-year disease-related mortality after resection for pancreatic cancer is approximately 30%. This study examined potential preoperative parameters that would help avoid unnecessary surgery.

METHODS

Among the patients resected at our institution from 1997 to 2006, a total of 228 underwent pancreatic resection for ductal adenocarcinoma. By means of a survival cutoff of 12 months, two groups were created: early death (ED) and long survivors. A logistic regression analysis was performed to identify perioperative predictors of ED.

RESULTS

Among 228 resected patients, postoperative mortality occurred in four cases (1.8%) that were excluded from the study. In the remaining 224 patients, 43 (19.2%) died of disease within 12 months from surgery (ED), and the remaining 181 (80.8%) had a longer survival. Multivariate analysis selected duration of preoperative symptoms > 40 days, CA 19-9 > 200 U/mL, pathological grading G3-G4, and R2 resection as independent predictors of ED.

CONCLUSIONS

Duration of symptoms, CA 19-9 serum level, and pathological grading possibly retrieved by endoscopic ultrasound-guided biopsy can be preoperatively used to identify patients with disease that is not suitable for up-front surgery, even if deemed resectable by high-quality imaging.

Does intrahepatic cholangiocarcinoma have better prognosis compared to perihilar cholangiocarcinoma?

BACKGROUND AND OBJECTIVES

Cholangiocarcinoma can be classified as intrahepatic (ICC) or perihilar (PCC). The objectives of this study is to evaluate the surgical outcomes of patients with PCC and ICC, identify the main prognostic factors related to survival and compare the outcome and the prognostic factors of PCC and ICC.

METHODS

Ninety-five out of 152 patients observed between January 1990 and December 2007 at Surgical Division of University of Verona Medical School underwent the resection of ICC (33 patients) or PCC (62 patients).

RESULTS

Overall median survival was 24 months with a 3- and 5-year survival rate of 45% and 23%, respectively. Prognostic factors for survival were macroscopic types of the tumor, the resection of extrahepatic bile duct, radical resection, lymph node metastases, and macro-vascular invasion. Survival was related with the macroscopic type of the tumors with a 5-year survival rate of 26% and 13% for ICC and PCC, respectively. Univariate analysis identified that negative clinico-pathological factors where significant more frequently found in PCC compared to ICC.

CONCLUSION

We identified that ICC have longer survival rate compared to PCC. PCC showed a higher frequency of negative clinico-pathological factors such as non-radical (R+) resection, perineural infiltration and macro-vascular invasion.

Pancreatic cystic endocrine tumors: a different morphological entity associated with a less aggressive behavior

BACKGROUND

Cystic pancreatic endocrine tumors (CPETs) are rare lesions and their biological features have been scarcely investigated.

AIM

To compare clinical and pathological features of resected non-functioning sporadic CPETs (NF-CPETs) with solid pancreatic endocrine tumors (SPETs) in a single-institution experience.

METHODS

All patients with a pathologically confirmed diagnosis of sporadic non-functioning pancreatic endocrine tumors who underwent curative resection between 1990 and 2008 were included. A comparison of demographic, clinical and pathological characteristics between CPETs and SPETs was made. Univariate and multivariable analyses were performed to identify preoperative predictors of carcinoma (non-functioning pancreatic endocrine carcinoma).

RESULTS

Twenty-one (11.5%) patients with a histological diagnosis of NF-CPET were identified. The median age was 60 years (IQR 46.5-73.5 years) and a diagnosis of carcinoma (non-functioning pancreatic endocrine carcinoma) was made in 3 (14.3%) cases. In the comparison with NF-SPETs, no differences were found in terms of gender (p = 0.75), age (p = 0.81), presenting symptoms (p = 0.43), localization of the tumors (p = 0.46) and type of resection (p = 0.31). The incidence of non-functioning pancreatic endocrine carcinoma was significantly lower in the NF-CPET versus the NF-SPET group (14.3 vs. 40.4%, p = 0.04). By univariate analysis, preoperative predictors of non-functioning pancreatic endocrine carcinoma included the presence of symptoms (OR 3.96, 95% CI 2.06-7.63) and an increase in the absolute value of radiological diameter (OR 1.05, 95% CI 1.03-1.07). A cystic morphology of the lesion turned out to be a negative predictor of carcinoma (OR 0.25, 95% CI 0.70-0.87). These results were confirmed by multivariable analysis.

CONCLUSIONS

NF-CPETs have a measurable propensity to be benign. In those patients affected by small and asymptomatic NF-CPET a more conservative surgical approach or a follow-up policy could be considered.

Resectable pancreatic adenocarcinoma: is the enhancement pattern at contrast-enhanced ultrasonography a pre-operative prognostic factor?

The aim of our study was to determine whether the enhancement pattern of pancreatic adenocarcinoma at contrast-enhanced ultrasonography (CEUS) is related to patient prognosis after resection. CEUS of 42 resected adenocarcinomas were retrospectively reviewed. Tumors were divided into two groups: group A=poorly vascularized (presence of avascular areas) or group B=well vascularized (absence of avascular areas). All lesions were resected and underwent pathological examination assessing tumor differentiation as: undifferentiated (poorly differentiated) or differentiated (moderately and well differentiated). Mean vascular density (MVD) was also evaluated. CEUS enhancement and pathology were correlated (Spearman's test). Survival was analyzed with the Kaplan-Meier method. Multivariate analysis was performed with the Cox regression model. There were 30 differentiated and 12 undifferentiated adenocarcinomas at pathology. At CEUS, 10 lesions were poorly vascularized, whereas 32 lesions were well vascularized. Positive correlation was observed between CEUS groups and tumoral differentiation (rs=0.51; p=0.001) and between CEUS and MVD (rs=0.74; p<0.0001). Median survival in patients with group A vascularization at CEUS was significantly lower than in group B (p=0.015). Cox proportional hazard model revealed the presence of poorly vascularized tumor at CEUS (p=0.0001) as a predictor of higher mortality. In conclusion, CEUS enables accurate depiction of the vascularization of adenocarcinoma, with positive correlation to histology grade and MVD.

Main pancreatic duct intraductal papillary mucinous neoplasms: accuracy of MR imaging in differentiation between benign and malignant tumors compared with histopathologic analysis

PURPOSE

To retrospectively determine the accuracy of magnetic resonance (MR) imaging combined with MR cholangiopancreatography (CP) in differentiating benign from malignant intraductal papillary mucinous neoplasms (IPMNs) involving the main pancreatic duct (MPD), with histopathologic analysis as the reference standard.

MATERIALS AND METHODS

The informed consent requirement was waived for this institutional review board-approved study. A total of 51 patients with histopathologically proved IPMNs (MPD IPMN, n = 29; mixed type IPMN, n = 22), underwent MR imaging, MR CP, and surgery, with a mean interval of 2.6 months between MR examination and surgery. Qualitative image analysis included assessment of the site of MPD dilatation (head of the pancreas, body and/or tail of the pancreas, or diffuse), presence or absence of duct wall nodules, and contrast enhancement of the MPD walls. Quantitative image analysis included measurement of the maximum diameter of the MPD. A comparison of adenomas and borderline IPMNs with cancerous IPMNs was performed with the Student t test or the Mann-Whitney U test for continuous variables.

RESULTS

At histopathologic analysis, 27 IPMNs were classified as carcinomas; 13, as borderline tumors; and 11, as adenomas. MPD wall nodules were observed in 16 carcinomas involving the MPD and one adenoma or borderline neoplasm (P < .00001). Duct wall enhancement was observed in 20 MPD or mixed type carcinomas and five adenomas or borderline neoplasms (P = .0001). The median maximal diameter of the MPD was 18 mm in malignant MPD or mixed type IPMNs and 11 mm in benign borderline IPMNs (P = .038). No significant difference in the overall 5-year survival rate of patients with MPD IPMNs and those with mixed type IPMNs was observed (P = .813).

CONCLUSION

Duct wall nodules and enhancement of the MPD walls are signs of malignant MPD or mixed type IPMNs.

SUPPLEMENTAL MATERIAL

http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.2531080604/-/DC1.

Small undifferentiated pancreatic adenocarcinoma which mimics IPMN at imaging

CONTEXT

To present the case of an unusual presentation at imaging of a very small solid undifferentiated pancreatic adenocarcinoma which mimics a side-branch intraductal papillary mucinous neoplasm.

CASE REPORT

The patient came to our hospital for a revaluation of a cystic pancreatic lesion. Ultrasound (US) and contrast-enhanced ultrasound (CEUS) examinations were carried out. A small cystic lesion of about 1.5 cm in diameter was seen in the posterior aspect of the pancreatic uncinate process A very small, solid, vascularized nodule was detected at CEUS within the lesion. Consequently, the patient underwent CT and MRI. MRI confirmed the presence of an intralesional nodule and communication with the main pancreatic duct was demonstrated, suggesting the diagnosis of intraductal papillary mucinous neoplasm with solid intralesional tissue. A pylorus preserving pancreaticoduodenectomy was carried out. An undifferentiated adenocarcinoma having a notable peripheral inflammatory reaction and dilated branch duct was finally diagnosed.

CONCLUSION

To our knowledge, we present for the first time, the case of a very small solid undifferentiated pancreatic adenocarcinoma of the uncinate process which mimicked a side-branch intraductal papillary mucinous neoplasm at imaging. The cystic appearance may be an epiphenomenon of a solid lesion and this possibility has to be considered when one encounters incidental cystic lesions at imaging.

Cathepsin-k as a diagnostic marker in the identification of micro-granulomas in Crohn's disease

Crohn's disease is a chronic inflammatory bowel disease, whose aetiology and pathogenesis are still unknown. The occurrence of epithelioid granulomas is one characteristic feature of the disease since these lesions are found in the bowel wall in 50-87% of colectomy specimens. Although granulomas are not pathognomonic, their identification is considered a relevant element for diagnosis. Cathepsin-k, a papain-like cysteine protease, is involved in bone remodelling, and has been widely used as a immunohistochemical marker for the in situ detection of osteoclasts. Interestingly, the expression of this potent protease is also significantly increased in stimulated tissue macrophages, epithelioid cells and granulomas, but is not expressed in resident tissue macrophages. In the present study, we evaluated Cathepsin-k expression as a diagnostic tool in the identification of small granulomas in Crohn's disease. Formalin-fixed and paraffin-embedded samples of 10 cases of Crohn's disease were collected from surgical ileo-colic resections followed by comparison of Cathepsin-k and CD68 immunoreactivity. Granulomas were identified in 4 of 10 cases examined in haematoxylin & eosin preparations. Cathepsin-k enabled the identification of small granulomas (with a diameter between 100 and 200 microm) in 6 of 10 cases, mainly localized within the submucosa and muscular layers. When compared to CD68, Cathepsin-k immunoreactivity was generally absent or only weakly expressed in resting tissue macrophages, thus allowing better identification of activated epithelioid cells. Based on these results, Cathepsin-k appears to be a reliable tool for the precise and rapid identification of small epithelioid granulomas in Crohn's disease.

Endocrine neoplasms of the pancreas: pathologic and genetic features

CONTEXT

Pancreatic endocrine neoplasms (PENs) are diagnostically challenging tumors whose natural history is largely unknown. Histopathology allows the distinction of 2 categories: poorly differentiated high-grade carcinomas and well-differentiated neoplasms. The latter include more than 90% of PENs whose clinical behavior varies from indolent to malignant and cannot be predicted by their morphology.

OBJECTIVES

To review the literature and report on additional primary material about the clinicopathologic features, classification, staging, grading, and genetic features of PENs.

DATA SOURCES

Literature review of relevant articles indexed in PubMed (US National Library of Medicine) and primary material from the authors' institution.

CONCLUSIONS

The diagnosis of PEN is generally easy, but unusual features may induce misdiagnosis. Immunohistochemistry solves the issue, provided that the possibility of a PEN has been considered. Morphology allows the distinction of poorly differentiated aggressive carcinomas from well-differentiated neoplasms. The World Health Organization classification criteria allow for the discernment of the latter into neoplasms and carcinomas with either benign or uncertain behavior. The recently proposed staging and grading systems hold great promise for permitting a stratification of carcinomas into clinically significant risk categories. To date, inactivation of the MEN1 gene remains the only ascertained genetic event involved in PEN genesis. It is inactivated in roughly one-third of PENs. The degree of genomic instability correlates with the aggressiveness of the neoplasm. Gene silencing by promoter methylation has been advocated, but a formal demonstration of the involvement of specific genes is still lacking. Expression profiling studies are furnishing valuable lists of mRNAs and noncoding RNAs that may advance further the research to discover novel markers and/or therapeutic targets.

Endocrine neoplasms of the pancreas: pathologic and genetic features

CONTEXT

Pancreatic endocrine neoplasms (PENs) are diagnostically challenging tumors whose natural history is largely unknown. Histopathology allows the distinction of 2 categories: poorly differentiated high-grade carcinomas and well-differentiated neoplasms. The latter include more than 90% of PENs whose clinical behavior varies from indolent to malignant and cannot be predicted by their morphology.

OBJECTIVES

To review the literature and report on additional primary material about the clinicopathologic features, classification, staging, grading, and genetic features of PENs.

DATA SOURCES

Literature review of relevant articles indexed in PubMed (US National Library of Medicine) and primary material from the authors' institution.

CONCLUSIONS

The diagnosis of PEN is generally easy, but unusual features may induce misdiagnosis. Immunohistochemistry solves the issue, provided that the possibility of a PEN has been considered. Morphology allows the distinction of poorly differentiated aggressive carcinomas from well-differentiated neoplasms. The World Health Organization classification criteria allow for the discernment of the latter into neoplasms and carcinomas with either benign or uncertain behavior. The recently proposed staging and grading systems hold great promise for permitting a stratification of carcinomas into clinically significant risk categories. To date, inactivation of the MEN1 gene remains the only ascertained genetic event involved in PEN genesis. It is inactivated in roughly one-third of PENs. The degree of genomic instability correlates with the aggressiveness of the neoplasm. Gene silencing by promoter methylation has been advocated, but a formal demonstration of the involvement of specific genes is still lacking. Expression profiling studies are furnishing valuable lists of mRNAs and noncoding RNAs that may advance further the research to discover novel markers and/or therapeutic targets.