Pancreatic manifestations of von Hippel-Lindau disease

von Hippel-Lindau disease-related neoplasia with an emphasis on renal manifestations

von Hippel-Lindau (VHL) disease is characterized by biallelic inactivation of the VHL gene leading to abnormal or absent VHL protein function, and constitutive activation of hypoxia-inducible factors (HIF) that leads to pro-tumorigenic signaling. Individuals with VHL disease develop numerous cysts and tumors involving multiple organs including the kidneys, central nervous system, endolymphatic sac, lungs, pancreatobiliary system, adrenal glands, epididymis, and/or broad ligament. On histologic examination, these lesions show morphologic overlap as they are frequently characterized by cells with clear cytoplasm and prominent vascularity. In addition to distinguishing non-renal tumors from metastatic clear cell renal cell carcinoma, understanding site-specific histopathologic and immunophenotypic features of these tumors has several applications. This includes distinguishing VHL-related tumors from those that arise sporadically and lack VHL gene alterations, guiding further genetic workup, and helping distinguish between different genetic predisposition syndromes. In this context, immunohistochemical studies for markers such as paired box 8 (PAX-8), carbonic anhydrase 9 (CA9), and glucose transporter 1 (GLUT-1) have an important role in routine clinical practice and represent cost-effective diagnostic tools. The recent development of targeted therapeutics directed against HIF-mediated signaling represents a significant milestone in the management of VHL disease and highlights the importance of accurately diagnosing and characterizing the wide spectrum of VHL disease-associated lesions.

An update on genetically engineered mouse models of pancreatic neuroendocrine neoplasms

Pancreatic neuroendocrine neoplasms (PanNENs) are rare and clinically challenging entities. At the molecular level, PanNENs' genetic profile is well characterized, but there is limited knowledge regarding the contribution of the newly identified genes to tumor initiation and progression. Genetically engineered mouse models (GEMMs) are the most versatile tool for studying the plethora of genetic variations influencing PanNENs' etiopathogenesis and behavior over time. In this review, we present the state of the art of the most relevant PanNEN GEMMs available and correlate their findings with the human neoplasms' counterparts. We discuss the historic GEMMs as the most used and with higher translational utility models. GEMMs with Men1 and glucagon receptor gene germline alterations stand out as the most faithful models in recapitulating human disease; RIP-Tag models are unique models of early-onset, highly vascularized, invasive carcinomas. We also include a section of the most recent GEMMs that evaluate pathways related to cell cycle and apoptosis, Pi3k/Akt/mTOR, and Atrx/Daxx. For the latter, their tumorigenic effect is heterogeneous. In particular, for Atrx/Daxx, we will require more in-depth studies to evaluate their contribution; even though they are prevalent genetic events in PanNENs, they have low/inexistent tumorigenic capacity per se in GEMMs. Researchers planning to use GEMMs can find a road map of the main clinical features in this review, presented as a guide that summarizes the chief milestones achieved. We identify pitfalls to overcome, concerning the novel designs and standardization of results, so that future models can replicate human disease more closely.

Pancreatic insufficiency following pancreatectomy: Does underlying tumor syndrome confer a greater risk?

BACKGROUND

The risk of postoperative pancreatic exocrine insufficiency (PPEI) is unknown in patients with multiple endocrine neoplasia type I (MEN1) and von Hippel-Lindau (VHL) who require resection of pancreatic neuroendocrine tumors (PNETs).

METHODS

A retrospective review of patients who underwent resection of PNETs at the National Institutes of Health from 2007 to 2019 was performed.

RESULTS

Our cohort included 82 patients (VHL n = 25, MEN1 n = 20, sporadic n = 37), 6 of whom developed PPEI. While VHL compared to all non-VHL patients (p = 0.046), non-functional PNETs (p = 0.050), and pancreaticoduodenectomy (PD) (p=<0.001) were associated with higher rates of PPEI on univariate analysis, only PD was found to be an independent predictor of PPEI on multivariate analysis (OR 14.43, 95% CI 1.43-145.8, p = 0.024).

CONCLUSIONS

The rate of PPEI in patients with hereditary tumor syndromes was similar to that of sporadic PNETs. PD was independently associated with PPEI, and this increased risk should be included in preoperative counseling.

Inherited syndromes involving pancreatic neuroendocrine tumors

Inherited syndromes are important to recognize in the setting of a pancreatic neuroendocrine tumor (PNET) as there are significant implications for the patient's medical management and opportunity for early detection of subsequent manifestations. Although most PNETs are sporadic, approximately 10% are due to an inherited syndrome, which include multiple endocrine neoplasia type 1 (MEN1), multiple endocrine neoplasia type 4 (MEN4), von Hippel-Lindau disease (VHL), neurofibromatosis type 1 (NF1), and tuberous sclerosis complex (TSC). The general hallmarks of a hereditary endocrine neoplasia predisposition syndrome include any one of the following: multiple primary tumors (in the same or different organs), rare tumors (prevalence of less than 1 in 1,000 people in the general population), earlier age of diagnosis (usually under the age of 40), characteristic pattern of disease in the individual or family (phenotype and inheritance pattern). These syndromes are monogenic (due to a single gene disorder), highly penetrant (with all carriers of the disease exhibiting at least part of the phenotype) and can display variable expressivity (where affected individuals may have different presentations and features of the disease). A thoughtful approach to management is required, even if the presenting symptom is resolved, as these syndromes often involve multi-organ disease with a lifelong risk for tumor development. Additionally, the natural history of tumors in the setting of a hereditary condition may be different than would be expected in a sporadic form of the disease. For example, in some circumstances the risk of metastatic disease is lower, and therefor longer observation is the preferred approach over early surgical intervention. The unique aspects to management, challenges in hereditary disease recognition and accurate diagnosis, and rarity of these syndromes are all reasons to support referral to high-volume centers with the experience and knowledge to treat patients with hereditary endocrine neoplasia syndromes.

Stabilization of HIF-2α impacts pancreas growth

Hypoxia inducible factors (HIFs) are critical regulators of the response to oxygen deficiency by activating target genes involved in a variety of biological functions. HIFs have been implicated in the pathophysiology of numerous pathologies including cancer. Patients with mutations in the von Hippel-Lindau (VHL) gene, an essential regulator of HIF activity, develop tumors in several organs including the pancreas. Previous functional studies of HIF activation in the pancreas have used Vhlh (the murine homolog of VHL) deficient mice. However, the role of each specific HIF transcription factors in the pancreas has not been thoroughly examined. We derived mice that constitutively express a normoxia-stable form of HIF2α in the pancreas. Activation of HIF2α in the pancreas severely impairs postnatal exocrine pancreas. Mice with pancreas-specific activation of HIF2α develop histological features reminiscent of pancreatitis including loss of acinar cells, ductal dilation and fibrosis. Moreover, we provide evidence that signaling pathways important for acinar cell homeostasis are altered in HIF2α-overexpressing pancreata.

When should genetic testing be performed in patients with neuroendocrine tumours?

Neuroendocrine tumours (NETs) are a heterogenous group of tumours arising from neuroendocrine cells in several sites around the body. They include tumours of the gastroenteropancreatic system, phaeochromocytoma and paraganglioma and medullary thyroid cancer. In recent years, it has become increasingly apparent that a number of these tumours arise as a result of germline genetic mutations and are inherited in an autosomal dominant pattern. The number of genes implicated is increasing rapidly. Identifying which patients are likely to have a germline mutation enables clinicians to counsel patients adequately about their future disease risk, and allows for earlier detection of at-risk patients through family screening. The institution of screening and surveillance programmes may in turn lead to a major shift in presentation patterns for some of these tumours. In this review, we examine the features which may lead a clinician to suspect that a patient may have an inherited cause of a NET and we outline which underlying conditions should be suspected. We also discuss what type of screening may be appropriate in a variety of situations.

Von Hippel-Lindau Disease With Multi-Organ Involvement: A Case Report and 8-Year Clinical Course With Follow-Up

Patient: Female, 31

Final Diagnosis: Von Hippel-Lindau disease

Symptoms: Abdominal pain

Medication: —

Clinical Procedure: Splenectomy

Specialty: Oncology

Management Strategies and Outcomes for VHL-related Craniospinal Hemangioblastomas

Hemangioblastomas are rare and benign tumors accounting for less than 2% of all central nervous system (CNS) tumors. The vast majority of hemangioblastomas occur sporadically, whereas a small number of cases, especially in younger patients, are associated with Von Hippel–Lindau (VHL) syndrome. It is thought that loss of tumor suppressor function of the VHL gene results in stabilization of hypoxia-inducible factor alpha with downstream activation of cellular proliferative and angiogenic genes that promote tumorigenesis. VHL-related hemangioblastomas predominantly occur in the cerebellum and spine. Lesions are often diagnosed on contrast-enhanced craniospinal MRIs, and the diagnosis of VHL occurs through assessment for germline VHL mutations. Surgical resection remains the primary treatment modality for symptomatic or worrisome lesions, with excellent local control rates and neurological outcomes. Stereotactic radiotherapy can be employed in patients who are deemed high risk for surgery, have multiple lesions, or have non-resectable lesions. Given the tendency for development of either new or multiple lesions, close radiographic surveillance is often recommended for asymptomatic lesions.

Endocrine manifestations of von Hippel-Lindau disease

von Hippel-Lindau (VHL) disease is an autosomal dominant disorder caused by heterozygous mutations in the VHL tumor suppressor gene that is characterized by the occurrence of multiple endocrine and nonendocrine lesions. This review focuses on the endocrine manifestations of VHL disease. Pancreatic neuroendocrine proliferations (ductuloinsular complexes, islet dysplasia, endocrine microadenoma, and neuroendocrine tumors), pheochromocytomas, and extra-adrenal paragangliomas are important endocrine manifestations of VHL disease. They frequently display characteristic clinical, biochemical, and histopathologic features that, although not pathognomonic, can be helpful in suggesting VHL disease as the underlying etiology and distinguishing these tumors from sporadic cases. Recent improvements in treatment and outcomes of renal cell carcinomas have allowed pancreatic neuroendocrine tumors to emerge as a significant source of metastatic disease, making the accurate recognition and classification of these neoplasms by the pathologist of utmost importance to determine prognosis, treatment, and follow-up strategies for affected patients.

Implications of Von Hippel-Lindau Syndrome and Renal Cell Carcinoma

Von Hippel-Lindau syndrome (VHLS) is a rare hereditary neoplastic disorder caused by mutations in the vhl gene leading to the development of tumors in several organs including the central nervous system, pancreas, kidneys, and reproductive organs. Manifestations of VHLS can present at different ages based on the affected organ and subclass of disease. In the subclasses of VHLS that cause renal disease, renal involvement typically begins closer to the end of the second decade of life and can present in different ways ranging from simple cystic lesions to solid tumors. Mutations in vhl are most often associated with clear cell renal carcinoma, the most common type of renal cancer, and also play a major role in sporadic cases of clear cell renal carcinoma. The recurrent, multifocal nature of this disease presents difficult challenges in the long-term management of patients with VHLS. Optimization of renal function warrants the use of several different approaches common to the management of renal carcinoma such as nephron sparing surgery, enucleation, ablation, and targeted therapies. In VHLS, renal lesions of 3 cm or bigger are considered to have metastatic potential and even small lesions often harbor malignancy. Many of the aspects of management revolve around optimizing both oncologic outcome and long-term renal function. As new surgical strategies and targeted therapies develop, the management of this complex disease evolves. This review will discuss the key aspects of the current management of VHLS.

Pancreatic lesions in von Hippel-Lindau disease? A systematic review and meta-synthesis of the literature

BACKGROUND

von Hippel-Lindau (vHL) disease is a rare condition that leads to characteristic lesions within many different body systems. Pancreatic manifestations of vHL cover a wide spectrum of pathologies, and thus, accurate characterization and management is critical.

METHODS

A comprehensive and systematic text word and MeSH search of the medical literature was performed to identify studies where information regarding the prevalence, clinical characteristics, and management recommendations could be extracted.

RESULTS

Eleven studies were identified but 2 studies utilized the same data set. Of the 10 remaining studies, a total of 1,442 patients with vHL were available for analysis. Four hundred and twenty patients were examined for any type of pancreatic lesion, 362 for simple cysts or serous cystadenomas (SCAs), and 1,442 for neuroendocrine tumors (NETs). Of the 420 assessed for any pancreatic manifestation of vHL, 252 (60%) had a pancreatic lesion identified. Simple cysts that present as the sole manifestation of pancreatic disease were common and found in 169 of 362 (47%) patients. These are usually asymptomatic and do not normally require intervention. SCAs were reported in 39 of 362 (11%) patients and followed a similar benign course; resection is acceptable in symptomatic patients. NETs were identified in 211 of 1,442 (15%) patients, and 27 of 1,442 (2%) lesions behaved malignantly. Management of NETs depends on size, doubling time, and underlying genetics. Renal cell carcinoma is a characteristic in vHL, but there were no cases of pancreatic metastases identified from the included studies. Adenocarcinomas of the pancreas are not pathogenically linked to vHL.

CONCLUSIONS

This review highlights the wide spectrum and high prevalence of pancreatic lesions in vHL. Simple cysts and SCAs are benign, but NETs require careful observation due to their malignant potential.

Von hippel-lindau disease: a new approach to an old problem

BACKGROUND

Von Hippel-Lindau (VHL) disease is a hereditary, autosomal dominant syndrome which is manifested by a range of different benign and malignant tumors. This disease can present with different clinical presentations such as; retinal angioma (RA), hemangioblastoma (HB) of the central nervous system (CNS), pheochromocytoma (Pheo), and epididymal cystadenoma. Tumors are usually accompanied with cysts.

OBJECTIVES

As the disease can display different clinical presentations, which are mainly unspecific, and considering the importance of an early diagnosis and the proper and early management of it, this study was carried out to present a general overview of VHL. Moreover, the present article reviews screening methods and emphasizes the need for increasing the awareness of different health care professionals to diagnose and refer the patients in the early stages.

MATERIALS AND METHODS

A thorough search of internet medical databases, such as PubMed, was carried out on known or suggested; clinical presentations, pathogenesis, screening, causes and criteria for diagnosis of patients and their referrals.

RESULTS

Our research demonstrated that VHL is caused by a mutation in the von Hippel-Lindau (VHL) gene. It also showed that different screening methods can be utilized for the early diagnosis and referral of patients. Different clinical presentations of the disease are also elaborated in some detail and their treatment options are discussed.

CONCLUSIONS

Considering the need for a multidisciplinary approach to VHL, especially, given the number of cases which have been reported and diagnosed in Iran, it is of great importance that clinicians remain vigilant in order to identify cases that present with clinical characteristics of the disease, and that they are prompt in referring them to a multidisciplinary VHL clinic. It is also important to establish links with existing VHL Family Alliances and other related organizations around the world.

Role of cortical sparing adrenalectomy and novel variant of mutation in patient with von Hippel-Lindau disease

Neurofibromatosis type 1 is the most common phakomatoses and is inherited in autosomal dominant fashion with complete penetrance. Secondary hypertension is common in these patients due to various causes including adrenal tumors. Pheochromocytoma is a rare catecholamine producing tumor seen in 0.5% to 5% of patients with neurofibromatosis. The combination of pheochromocytoma with neurofibromatosis is rarely reported in the literature. We recently encountered an elderly lady with this combination who successfully underwent adrenalectomy. We report the case for the uncommon occurrence and to highlight the relevant literature review about pheochromocytoma in neurofibromatosis.