Presentation and outcome of mixed neuroendocrine non-neuroendocrine neoplasms of the pancreas

Mixed pancreatic ductal adenocarcinoma and well-differentiated neuroendocrine tumor: A case report

BACKGROUND

Pancreatic mixed neuroendocrine-non-neuroendocrine neoplasms (MiNENs) are rare malignancies affecting the pancreas. The World Health Organization defines MiNENs as neoplasms composed of morphologically recognizable neuroendocrine and non-neuroendocrine components, each constituting 30% or more of the tumor volume. Adenocarcinoma-neuroendocrine carcinoma is the most frequent MiNEN combination. A well-differentiated neuroendocrine tumor (NET) component is rarely reported in MiNENs.

CASE SUMMARY

Here we report a rare case with intermingled components of ductal adenocarcinoma and grade 1 well-differentiated NET in the pancreas. The two tumors show distinct histology and significant differentiation discrepancy (poorly differentiated high grade adenocarcinoma and well-differentiated low grade NET), and also present as metastases in separate lymph nodes. Next generation sequencing of the two components demonstrates KRAS and TP53 mutations in the ductal adenocarcinoma, but no genetic alterations in the NET, suggesting divergent origins for these two components. Although tumors like this meet the diagnostic criteria for MiNEN, clinicians often find the diagnosis and staging confusing and impractical for clinical management.

CONCLUSION

Mixed NET/non-NET tumors with distinct histology and molecular profiles might be better classified as collision tumors rather than MiNENs.

Resolution of paraneoplastic palmoplantar keratoderma after treating mixed serous neuroendocrine tumor of the pancreas: a case report and literature review

Palmoplantar keratodermas (PPKs), also known as 'keratosis palmaris et plantaris', are a heterogeneous group of disorders characterized by abnormal thickening of the epidermal skin of the palms and soles leading to hyperkeratosis. It could be acquired or hereditary. Acquired PPK often occurs as a paraneoplastic syndrome as well as a stigma of other dermatoses. We report a rare case of paraneoplastic PPK secondary to mixed neuroendocrine tumor of the pancreas with complete remission after surgical excision of the cancer.

Mixed neuroendocrine non-neuroendocrine neoplasms in gastroenteropancreatic tract

Mixed neuroendocrine non-neuroendocrine neoplasms (MiNENs) are a heterogeneous group of malignant neoplasms that can settle in the gastroenteropancreatic tract. They are composed of a neuroendocrine (NE) and a non-NE component in at least 30% of each tumour. The non-NE component can include different histological combinations of glandular, squamous, mucinous and sarcomatoid phenotypes, and one or both of the components can be low-or high grade malignant. Recent changes in the nomenclature of these neoplasms might lead to great deal of confusion, and the lack of specific clinical trials is the main reason why their management is difficult. The review aims to clarify the definition of MiNEN and analyze available evidence about their diagnosis and treatment options according to their location and extension through careful analysis of the available data. It would be important to reach a general consensus on their diagnosis in order to construct a classification that remains stable over time and facilitates the design of clinical trials that, due to their low incidence, will require long recruitment periods.

Mixed Acinar Neuroendocrine Carcinoma of the Pancreas: Comparative Population-Based Epidemiology of a Rare and Fatal Malignancy in The United States

Mixed acinar neuroendocrine carcinoma of the pancreas (MANEC-P) is an extremely rare malignancy with a poor prognosis. However, epidemiological estimates of MANEC-P remain unknown. This study aimed to estimate and compare the incidence, prevalence, and cancer-specific survival (CSS) of MANEC-P in the United States (US). Patients with MANEC-P were identified through the Surveillance, Epidemiology, and End Results (SEER) and National Program of Cancer Registries databases between 2000-2017. The primary outcomes included age-adjusted incidence rate, limited-duration prevalence, and CSS. A total of 630 patients were identified for the incidence analysis and 149 for the prevalence and CSS analyses. The MANEC-P incidence rate was 0.011 per 100,000 individuals, which was the lowest among pancreatic cancer histologic subtypes. The incidence rate was significantly higher in men and Black races and peaked at 75-79 years of age. The incidence rate was the lowest in the midwestern region (0.009) and the highest in the northeastern US (0.013). The 17-year prevalence was 0.00005%, indicating that 189 patients were alive in the United States at the beginning of 2018. The median CSS of MANEC-P was estimated to be 41 (23, 69) months. In conclusion, MANEC-P is very rare, and its incidence rate has been steady in the US over the last two decades. MANEC-P has a poor prognosis and is the 5th leading cause of pancreatic cancer-related death in the US.

CT and MR imaging features of mixed neuroendocrine-non-neuroendocrine neoplasm of the pancreas compared with pancreatic ductal adenocarcinoma and neuroendocrine tumor

OBJECTIVE

This study aimed to assess the computed tomography (CT) and magnetic resonance imaging (MRI) features of pancreatic mixed neuroendocrine-non-neuroendocrine neoplasm (MiNEN) and compare them with those of pancreatic ductal adenocarcinoma (PDAC) and neuroendocrine tumor (NET).

METHODS

Twelve patients with pancreatic MiNEN, 24 patients with PDAC, and 24 patients with NET, who underwent both contrast-enhanced CT and MRI, were included. Clinical data and the key imaging features were retrospectively evaluated by two independent readers and compared between MiNEN and PDAC or NET. Univariate and multivariable logistic regression analyses were performed to obtain predictors for pancreatic MiNEN.

RESULTS

Patients with pancreatic MiNEN more frequently presented with large size and heterogeneous and cystic components compared with PDAC (p < 0.031) and ill-defined irregular margins, progressive enhancement, and adjacent organ involvement compared with NET (p < 0.036). However, vascular invasion was less commonly seen in MiNEN than PDAC (p = 0.010). Moderate enhancement was observed more frequently in MiNEN than in PDAC or NET (p < 0.001). Multivariate logistic analyses demonstrated that moderate enhancement and ill-defined irregular margin were the most valuable features for the prediction of pancreatic MiNEN (p ≤ 0.044). The combination of the two features resulted in a specificity of 93.8%, sensitivity of 83.3%, and accuracy of 91.7%.

CONCLUSIONS

We have mainly described the radiological findings of pancreatic MiNEN with ill-defined irregular margin and moderate enhancement compared with PDAC and NET. The combination of imaging features could improve diagnostic efficiency and help in the selection of the correct treatment method.

Pancreatic mixed acinar-neuroendocrine carcinoma in a patient with a germline BRCA2 mutation: a case report

Loss of function in the BRCA2 gene exacerbates ovarian, breast, and pancreatic ductal cancer risk. Despite being implicated in the pancreatic ductal epithelium carcinogenesis, the involvement of a germline BRCA2 mutation in acinar and endocrine cells is less reported. A 45-year-old woman with a history of breast cancer was referred to our hospital for a detailed examination of epigastric pain. Her father had pancreatic cancer, and her paternal aunt had a history of breast cancer. Contrast-enhanced computed tomography revealed a round tumor with a contrast effect in the pancreatic head. The patient underwent pancreaticoduodenectomy, and postoperative pathology and genetic testing revealed amphicrine-type mixed acinar-neuroendocrine carcinoma with a germline BRCA2 mutation. Recent studies have reported the BRCA2 mutation in genome sequencing of pancreatic acinar cell carcinoma and neuroendocrine tumor; perhaps, genetic testing for the BRCA2 mutation is feasible for patients with mixed neuroendocrine-non-neuroendocrine neoplasm.

Pancreatic Adeno-MiNEN, a Rare Newly Defined Entity with Challenging Diagnosis and Treatment: A Case Report with Systematic Literature Review and Pooled Analysis

Mixed neuroendocrine non-neuroendocrine neoplasms (MiNEN) are a peculiar entity that can occur throughout the whole gastrointestinal trait, and pancreatic localization is rare. Their main characteristic is the presence of at least a neuroendocrine and an epithelial component, each accounting for at least 30% of the tumour mass. The presence of epithelial ductal component defines adeno-MiNEN. We report a case of a 59-year-old woman affected by pancreatic adeno-MiNEN with challenging diagnosis and successfully treated. A systematic literature review and pooled analysis was also performed, aiming to define the management and outcomes of pancreatic adeno-MiNEN. Out of 190 identified records, 15 studies including 28 patients affected by pancreatic-adeno-MiNEN were included in the analysis. Pancreatic adeno-MiNEN occurred mainly in males (82.8%) and at a mean age of 61.7 (range: 24–82) years. Pre-operative diagnosis was possible only in 14.2% of cases. At presentation, the majority had already advanced disease (TNM stage III (53.8%) and stage IV 19.3%). Adjuvant therapy was performed in 55% of patients, and the tumour recurrence rate was in 30% of cases. Median disease-free survival (DFS) was 12 months (range: 0–216 months) with a 5-year DFS of 16.6%, while the median overall survival (OS) was 12 months (range: 0–288 months) with a 5-year OS of 23.5%. Pancreatic adeno-MiNENs are rare; as they have very heterogenous behaviour, they are rarely diagnosed preoperatively and have poor prognosis. Treatment of localised MiNEN still relies on radical surgical resection, which seems essential to achieve a good oncological prognosis. International registry on MiNEN is necessary to improve the knowledge on this rare tumour and to improve its outcomes.

Surgery in Patients with Gastro-Entero-Pancreatic Neuroendocrine Carcinomas, Neuroendocrine Tumors G3 and High Grade Mixed Neuroendocrine-Non-Neuroendocrine Neoplasms

OPINION STATEMENT

In the 2019 WHO guidelines, the classification of gastro-entero-pancreatic neuroendocrine neoplasms (GEP NEN) has changed from one being based on Ki-67 proliferation index alone to one that also includes tumor differentiation. Consequently, GEP NENs are now classified as well-differentiated neuroendocrine tumor (NET), NET G1 (Ki-67 <3%), NET G2 (Ki-67 3-20%) and NET G3 (Ki-67 >20%), and poorly differentiated neuroendocrine carcinoma (NEC) (Ki-67 >20%). It has been suggested that NET G3 should be treated as NET G2 with respect to surgery, while surgical management of NEC should be expanded from local disease to also include patients with advanced disease where curative surgery is possible. High grade mixed neuroendocrine-non-neuroendocrine neoplasms (MiNEN) have a neuroendocrine and a non-neuroendocrine component mostly with a poor prognosis. All studies evaluating the effect of surgery in NEC and MiNEN are observational and hold a risk of selection bias, which may overestimate the beneficial effect of surgery. Further, only a few studies on the effect of surgery in MiNEN exist. This review aims to summarize the data on the outcome of surgery in patients with GEP NET G3, GEP NEC and high grade MiNEN. The current evidence suggests that patients with NEN G3 and localized disease and NEN G3 patients with metastatic disease where curative surgery can be achieved may benefit from surgery. In patients with MiNEN, it is currently not possible to evaluate on the potential beneficial effect of surgery due to the low number of studies.

Mixed neuroendocrine–nonneuroendocrine neoplasms of the gastrointestinal system: An update

Mixed neuroendocrine-nonneuroendocrine neoplasms (MiNENs) of the digestive tract are a rare heterogeneous group of tumors that present many challenges in terms of diagnosis and treatment. Over the years, the diagnostic criteria, classification, and clinical behavior of these tumors have been the subjects of ongoing debate, and the various changes in their nomenclature have strengthened the challenges associated with MiNENs. This review is performed to provide an understanding of the key factors involved in the evolution of the designation of these tumors as MiNEN, highlight the current diagnostic criteria, summarize the latest data on pathogenesis and provide information on available treatments. Moreover, this work seeks to increase the awareness about these rare neoplasms by presenting the clinicopathological features and prognostic factors that play important roles in their behavior and discussing their different regions of origin in the gastrointestinal system (GIS). Currently, the MiNEN category also includes tumors in the GIS with a nonneuroendocrine component and epithelial tumors other than adenocarcinoma, depending on the organ of origin. Diagnosis is based on the presence of both morphological components in more than 30% of the tumor. However, this value needs to be reconfirmed with further studies and may be a limiting factor in the diagnosis of MiNEN by biopsy. Furthermore, available clinicopathological data suggest that the inclusion of amphicrine tumors in the definition of MiNEN is not supportive and warrants further investigation. The diagnosis of these tumors is not solely based on immunohistochemical findings. They are not hybrid tumors and both components can act independently; thus, careful grading of each component separately is required. In addition to parameters such as the metastatic state of the tumor at the time of diagnosis and the feasibility of surgical resection, the aggressive potential of both components has paramount importance in the choice of treatment. Regardless of the organ of origin within the GIS, almost MiNENs are tumors with poor prognosis and are frequently encountered in the elderly and men. They are most frequently reported in the colorectum, where data from molecular studies indicate a monoclonal origin; however, further studies are required to provide additional support for this origin.

Mixed neuroendocrine nonneuroendocrine neoplasms of the pancreas: a case report and literature review of pancreatic mixed neuroendocrine nonneuroendocrine neoplasm

A 36-year-old woman underwent left lateral hepatic lobectomy and tumor enucleation of the pancreatic head due to the diagnosis of mixed neuroendocrine nonneuroendocrine neoplasms (MiNENs). Her past medical history revealed an ill-defined mass in the pancreatic uncinate (approximately 1 cm in size) and liver nodules in segment II, suggesting a pancreatic neuroendocrine tumor (pNET) and liver metastases. After the operation, pathological examination showed that the lesion in the pancreas was MiNEN. The neuroendocrine component consisted of grade 1 (G1) NETs, and the nonneuroendocrine part was well-differentiated adenocarcinoma. Additionally, in hepatic lesions, the type of pancreaticobiliary duct in moderately differentiated adenocarcinoma indicated the source of tumor cells. We present the following case in accordance with the CARE reporting checklist. MiNENs of the pancreas are extremely rare and heterogeneous malignancies. Owing to the rarity of pancreatic MiNEN, no structured guidelines on preoperative diagnostics, therapy and follow-up exist thus far. Thus, problems in differential diagnosis and appropriate therapy may arise when treating suspected MiNEN patients. We performed a rigorous search on pancreatic MiNEN via PubMed and Web of Science. In total, 167 studies were identified, and 28 cases in 15 studies about pancreatic MiNEN were assessed. All the available information was listed and fully discussed.

Case report: composite pancreatic intraductal papillary mucinous neoplasm and neuroendocrine tumor: a new mixed neuroendocrine-non-neuroendocrine neoplasm?

BACKGROUND

Mixed neuroendocrine-non-neuroendocrine neoplasms (MiNEN) of the pancreas are extremely rare. Their pathogenesis and molecular landscape are largely unknown. Here, we report a case of mixed pancreatic intraductal papillary mucinous neoplasm (IPMN) and well-differentiated neuroendocrine tumor (NET) and identify its genetic alterations by next-generation sequencing (NGS).

CASE PRESENTATION

A fifty-year-old male was admitted into the hospital for evaluation of a pancreatic lesion detected during a routine examination. Abdominal ultrasound indicated a hypoechoic mass of 2.6 cm at the head of the pancreas. Malignancy was suspected and partial pancreatectomy was performed. Thorough histopathological examination revealed a mixed IPMN-NET. In some areas, the two components were relatively separated, whereas in other areas IPMN and NET grew in a composite pattern: The papillae were lined with epithelial cells of IPMN, and there were clusters of NET nests in the stroma of papillary axis. NGS revealed shared somatic mutations (KRAS, PCK1, MLL3) in both components. The patient has been uneventful 21 months after the surgery.

CONCLUSIONS

Our case provides evidence of a common origin for mixed IPMN-NET with composite growth features. Our result and literature review indicate that KRAS mutation might be a driver event underlying the occurrence of MiNEN. We also recommend the inclusion of mixed non-invasive exocrine neoplasms and neuroendocrine neoplasms into MiNEN.

Mixed neuroendocrine-non-neuroendocrine tumour of pancreas mimicking groove pancreatitis: Case report

Introduction

Mixed neuroendocrine-non-neuroendocrine neoplasm (MiNEN) is a rare tumour of the pancreas which can mimic groove pancreatitis.

Case report

We present a 49-year-old Indian male presented with constant, dull-aching epigastric pain for last 6 months radiating to back, not associated with jaundice, gastrointestinal bleed, fever or weight loss. He also had history of alcohol abuse for last 15 years. Physical examination was unremarkable. Laboratory investigations were within normal limits. Contrast enhanced computed tomography (CT) of the abdomen was suggestive of groove pancreatitis. CA 19.9, CEA and IgG4 levels were normal. Upper gastrointestinal endoscopy revealed an oedematous mucosa with narrowing of second part of duodenum. Endoscopic ultrasound (EUS) showed bulky pancreas with ill-defined heteroechoic head with periduodenal soft tissue thickening. EUS guided fine needle aspiration revealed chronic inflammatory cells. Based on the endoscopic findings and imaging, we suspected the diagnosis to be groove pancreatitis. He underwent open Whipple's pancreaticoduodenectomy. Histopathological evaluation revealed well differentiated neuroendocrine tumour and immunohistochemistry revealed features which was consistent with mixed neuroendocrine-non-neuroendocrine tumour (MiNEN). Post-operative period was uneventful and he was discharged on post-op day 7. A PET-CT scan was done to look for any silent metastasis and it was negative. He recieved 4 cycles of cisplatin-based chemotherapy. He was symptom free and doing well on 12 months follow up with no evidence of recurrence in surveillance CT imaging.

Discussion

Pancreatic MiNEN is characterised by presence of two malignant tissues, adenocarcinoma and NET, with one constituent involving at least 30% of the tumour. We report the pitfalls in diagnostic work-up which can lead to misdiagnosis of this rare entity. Specially due to admixture of different kinds of tissue, radiological investigations can be misleading.

Conclusion

Our case highlights the fact that MiNEN of pancreas can mimic a benign condition like groove pancreatitis. If routine histopathological and immunohistochemical evaluation is not done on the resected samples, relying on radiological and fine-needle aspiration cytology evidences, the actual diagnosis could be missed.

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MiNEN of pancreas is a rare pathology and difficult to diagnose preoperatively.

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MiNENs should be considered as a differential for groove pancreatitis.

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Histopathology with immunohistochemistry should be done for all pancreatoduodenectomy specimen to diagnose such rare tumors.

[Surgery for periampullary pancreatic cancer]

Periampullary neoplasms are a heterogeneous group of different tumor entities arising from the periampullary region, of which pancreatic ductal adenocarcinoma (PDAC) is the most common subgroup with 60-70%. As typical for pancreatic adenocarcinomas, periampullary pancreatic cancer is characterized by an aggressive growth and early systemic progression. Due to the anatomical location in close relationship to the papilla of Vater symptoms occur at an earlier stage of the disease, so that treatment options and prognosis are overall more favorable compared to pancreatic carcinomas at other locations. Nevertheless, the principles of treatment for periampullary pancreatic cancer are not substantially different from the standards for pancreatic cancer at other locations. A potentially curative approach for non-metastatic periampullary pancreatic cancer is a multimodal therapy concept, which includes partial pancreatoduodenectomy as a radical oncological resection in combination with a systemic adjuvant chemotherapy. As a result, long-term survival can be achieved in patients with favorable prognostic factors. In addition, with the continous development of surgery and systemic treatment potentially curative treatment concepts for advanced initially nonresectable tumors were also established, after completion of neoadjuvant treatment. This article presents the current surgical principles of a radical oncological resection for periampullary pancreatic cancer in the context of a multimodal treatment concept with an outlook for future developments of treatment.