Genetic disorders and insulinoma/glucagonoma.

Insulinoma and glucagonoma are two rare functioning neoplasms of the neuroendocrine cells of the pancreas, respectively, characterized by an uncontrolled over-secretion of insulin or glucagon, responsible for the development of the hypoglycemic syndrome and the glucagonoma syndrome. They prevalently arise as sporadic tumors; only about 10% of cases develop in the context of rare inherited tumor syndromes, such as multiple endocrine neoplasia type 1 (MEN1), neurofibromatosis type 1 (NF1), and tuberous sclerosis complex (TSC), being the result of an autosomal-dominant germline heterozygous loss-of-function mutation in a tumor-suppressor gene. Here, we reviewed the main epidemiological and clinical aspects of insulinoma and glucagonoma in the context of genetic syndromes.

A novel likely pathogenetic variant p.(Cys235Arg) of the MEN1 gene in multiple endocrine neoplasia type 1 with multifocal glucagonomas.

PURPOSE: Multiple endocrine neoplasia type 1 (MEN1) is a hereditary endocrine syndrome caused by pathogenic variants in MEN1 tumor suppressor gene. Diagnosis is commonly based on clinical criteria and confirmed by genetic testing. The objective of the present study was to report on a MEN1 case characterized by multiple pancreatic glucagonomas, with particular concern on the possible predisposing genetic defects. METHODS: While conducting an extensive review of the most recent scientific evidence on the unusual glucagonoma familial forms, we analyzed the MEN1 gene in a 35-year-old female with MEN1, as well as her son and daughter, using Sanger and next-generation sequencing (NGS) approaches. We additionally explored the functional and structural consequences of the identified variant using in silico analyses. RESULTS: NGS did not show any known pathogenic variant in the tested regions. However, a new non-conservative variant in exon 4 of MEN1 gene was found in heterozygosity in the patient and in her daughter, resulting in an amino acid substitution from hydrophobic cysteine to hydrophilic arginine at c.703T > C, p.(Cys235Arg). This variant is absent from populations databases and was never reported in full papers: its characteristics, together with the high specificity of the patient's clinical phenotype, pointed toward a possible causative role. CONCLUSION: Our findings confirm the need for careful genetic analysis of patients with MEN1 and establish a likely pathogenic role for the new p.(Cys235Arg) variant, at least in the rare subset of MEN1 associated with glucagonomas.

Necrolytic migratory erythema is an important visual cutaneous clue of glucagonoma.

Glucagonoma is an extremely rare neuroendocrine tumor that arises from pancreatic islet alpha cells. Although glucagonoma is usually accompanied by a variety of characteristic clinical symptoms, early diagnosis is still difficult due to the scarcity of the disease. In this study, we present the cumulative experiences, clinical characteristics and treatments of seven patients diagnosed with glucagonoma during the past 10 years at the First Affiliated Hospital of Xi'an Jiaotong University. The seven patients in our cohort consisted of six females and one male with an average diagnosis age of 40.1 years (range 23-51). The average time from onset of symptoms to diagnosis of glucagonoma was 14 months (range 2-36 months). All the patients visited dermatology first for necrolytic migratory erythema (NME) 7/7 (100%), and other presenting symptoms included diabetes mellitus (DM) 4/7 (57%), stomatitis 2/7 (28%), weight loss 4/7 (57%), anemia 4/7 (57%), diarrhea 1/7 (14%), and DVT1/7 (14%). Plasma glucagon levels were increased in all patients (range 216.92-3155 pg/mL) and declined after surgery. Imaging studies revealed that four of seven patients had liver metastasis. Six of seven patients received surgical resection, and all of them received somatostatin analog therapy. Symptoms improved significantly in 6 out of 7 patients. Three of seven patients died of this disease by the time of follow-up. Our data suggest that if persistent NME is associated with DM and high glucagon levels, timely abdominal imaging should be performed to confirm glucagonoma. Once diagnosed, surgery and somatostatin analogs are effective for symptom relief and tumor control.

Glucagonoma syndrome with atypical necrolytic migratory erythema.

Necrolytic migratory erythema is most commonly associated with glucagonoma syndrome. We report a rare case of glucagonoma syndrome with necrolytic migratory erythema presenting as pruritic papules and follicular pustules in a 57-year-old woman; showing eosinophilic infiltration on histology. However, the final diagnosis was confirmed by demonstrating neuroendocrine tumour on histopathological examination of the liver metastases. Nutrition therapy was administered as a palliative treatment. This case also highlights the atypical clinical features and nonspecific histology of necrolytic migratory erythema which makes the diagnosis difficult.

Glucagonoma syndrome with severe erythematous rash: A rare case report.

RATIONALE: Glucagonoma is a rare neuroendocrine tumor of the pancreas. Glucagonoma syndrome is often misdiagnosed as other skin lesions by clinicians due to a typical clinical sign of necrolytic migratory erythema (NME) with severe erythematous rash. PATIENT CONCERNS: A 48-year-old female patient was admitted to our department because she presented with unclear recurrent severe erythematous rash. The patient was diagnosed as skin disease. DIAGNOSES: Histopathologic examination revealed a pancreatic glucagonoma. Immnohistochemical staining of tumor tissue was positive for glucagon. INTERVENTIONS: The distal pancreatectomy plus splenectomy was performed in 2017. OUTCOMES: The skin lesions disappeared after surgery. She was followed up and showed no recurrence until now. LESSONS: Clinicians should consider the diagnosis of glucagonoma according to the typical initial symptoms. Early diagnosis is very important to provide a better prognosis. A multidisciplinary approach is effective in patients with unresectable metastatic tumors.

A Case Series of Molecular Imaging of Glucagonoma After Initial Therapy-68Ga-DOTATATE PET/CT Reveals Similar Results as in Neuroendocrine Tumors of Other Origin in Follow-up and Re-evaluation.

Glucagonoma is an extremely rare, glucagon-secreting neuroendocrine tumor of the pancreas. Only sparse data are available about the characteristics of this tumor in somatostatin receptor imaging and only for the situation of initial diagnosis. We present a series of 3 glucagonoma patients who underwent at least 1 Ga-DOTATATE PET/CT scan. All patients were diagnosed by either histology and/or elevated serum levels of glucagon. The presented cases suggest that somatostatin receptor-based imaging can probably be used for re-evaluation of disease status in patients with glucagonoma in a similar way as it is already established for neuroendocrine tumors of other origin.

Sweet´s syndrome and pancreatic neoplasm: an atypical association

El síndrome de Sweet es una dermatosis inflamatoria poco común, que se ha asociado a tumores malignos, principalmente de tipo hematológico. Presentamos un caso clínico de síndrome de Sweet asociado con una rara neoplasia pancreática, siendo uno de los pocos casos reportados en la literatura médica acerca de esta asociación.

Sweet's syndrome is an uncommon inflammatory dermatosis, which has been associated with malignant tumors, mainly of hematological type. We report a clinical case of Sweet syndrome associated with a rare pancreatic neoplasm, which is one of the few cases reported in the medical literature about this association.

Malignant transformation of glucagonoma with SPECT/CT In-111 OctreoScan features: A case report.

RATIONALE: Glucagonoma is an uncommon disease but it has been associated with a pattern of symptoms defined as glucagonoma syndrome. These symptoms, if promptly recognized, could help to speed up the diagnosing process. PATIENT CONCERNS: We report a case of a 68-year-old woman with a pancreatic glucagonoma. Her symptoms at the onset were typical of the glucagonoma syndrome. DIAGNOSES: After a significant weight loss, she underwent a computer tomography scan of the abdomen, which showed a hypervascular lesion of the tail of the pancreas and hypervascular lesions of the liver. An ultrasound guided biopsy was performed and pathology was consistent with glucagonoma. Her blood glucagon levels were elevated. OUTCOMES: She was treated with chemotherapy and somatostatin analogs. After 4 years, the disease had a malignant transformation, and metastases suddenly started to grow up. She stopped being responsive to treatment and eventually passed away. LESSONS: Due to its rarity, clinical diagnosis is challenging and generally it comes after a long interval since the onset of symptoms. Awareness of physicians and dermatologists of the characteristic necrolytic migratory erythema, and of the other symptoms, often leads to early diagnosis.

Characterization of pancreatic glucagon-producing tumors and pituitary gland tumors in transgenic mice overexpressing MYCN in hGFAP-positive cells.

Amplification or overexpression of MYCN is involved in development and maintenance of multiple malignancies. A subset of these tumors originates from neural precursors, including the most aggressive forms of the childhood tumors, neuroblastoma and medulloblastoma. In order to model the spectrum of MYCN-driven neoplasms in mice, we transgenically overexpressed MYCN under the control of the human GFAP-promoter that, among other targets, drives expression in neural progenitor cells. However, LSL-MYCN;hGFAP-Cre double transgenic mice did neither develop neural crest tumors nor tumors of the central nervous system, but presented with neuroendocrine tumors of the pancreas and, less frequently, the pituitary gland. Pituitary tumors expressed chromogranin A and closely resembled human pituitary adenomas. Pancreatic tumors strongly produced and secreted glucagon, suggesting that they derived from glucagon- and GFAP-positive islet cells. Interestingly, 3 out of 9 human pancreatic neuroendocrine tumors expressed MYCN, supporting the similarity of the mouse tumors to the human system. Serial transplantations of mouse tumor cells into immunocompromised mice confirmed their fully transformed phenotype. MYCN-directed treatment by AuroraA- or Brd4-inhibitors resulted in significantly decreased cell proliferation in vitro and reduced tumor growth in vivo. In summary, we provide a novel mouse model for neuroendocrine tumors of the pancreas and pituitary gland that is dependent on MYCN expression and that may help to evaluate MYCN-directed therapies.

The biology of glucagon and the consequences of hyperglucagonemia.

The proglucagon-derived peptide hormone, glucagon, comprises 29 amino acids. Its secretion from the pancreatic α cells is regulated by several factors. Glucagon increases blood glucose levels through gluconeogenesis and glycogenolysis. Elevated plasma concentrations of glucagon, hyperglucagonemia, may contribute to diabetes. However, hyperglucagonemia is also observed in other clinical conditions than diabetes, including nonalcoholic fatty liver disease, glucagon-producing tumors and after gastric bypass surgery. Here, we review the current literature on hyperglucagonemia in disease with a particular focus on diabetes, and finally speculate that the primary physiological importance of glucagon may not reside in glucose homeostasis but in regulation of amino acid metabolism exerted via a hitherto unrecognized hepato-pancreatic feedback loop.

Necrolytic migratory erythema and pancreatic glucagonoma.

Necrolytic migratory erythema is a rare paraneoplastic dermatosis that may be the first clinical manifestation of the glucagonoma syndrome, a disorder characterized by mucocutaneous rash, glucose intolerance, hypoaminoacidemia, hyperglucagonaemia and pancreatic glucagonoma. The clinical case of a 45-year-old woman is presented. She had been experiencing weight loss, polydipsia, polyphagia, postprandial emesis, excessive hair loss and abdominal pain for two months. Erythematous, scaly and migratory plaques with 20 days of evolution were found on her trunk, perineum, elbows, hands, feet, inframammary and antecubital folds. The skin biopsy revealed noticeable vacuolar changes in high epidermal cells, extensive necrosis and thin orthokeratotic cornified layer. These findings pointed to a diagnosis of necrolytic migratory erythema. A suggestion was made to investigate a pancreatic glucagonoma. Laboratory tests showed moderate anemia, hyperglycemia and marked hyperglucagonaemia. Abdominal ultrasound revealed a mass in the tail of the pancreas measuring 6 x 5 x 5 cm which was resected. The histopathological findings were compatible with a diagnosis of glucagonoma, as confirmed by immunohistochemistry. Skin symptoms disappeared 10 days after the tumor resection. We can conclude that the histological changes defined may be clues that can lead the search for a distant skin disease and allow for its diagnosis. The histological pattern of vacuolation and epidermal necrosis should arouse suspicion of pancreatic glucagonoma.

Glucagonoma syndrome: a review and update on treatment.

Glucagonoma syndrome is defined by the presence of an alpha-cell secreting tumour of the pancreas, elevated levels of glucagon, and a characteristic rash called necrolytic migratory erythema (NME). NME is usually a specific and often initial finding of glucagonoma syndrome, but it may occur in other settings unassociated with an alpha-cell pancreatic tumour (pseudoglucagonoma syndrome). Glucagonoma syndrome must be distinguished from pseudoglucagonoma syndrome. Prompt recognition of NME and subsequent workup for a glucagonoma can allow for an earlier diagnosis and enhance the chances of a favourable outcome. In particular, metastases occur late, so early recognition of glucagonoma syndrome before liver metastases can be life-saving. Surgical resection is the definitive treatment for glucagonoma syndrome, although chemotherapeutic agents, somatostatin analogues and radionuclide therapy are also employed. Herein, we offer an approach to workup after identifying NME and an update on its current treatment modalities.

[Neuroendocrine well-differentiated pancreatic tumors]. / Tumeurs neuro-endocrines bien différenciées du pancreas.

Neuroendocrine pancreatic tumors are rare tumors which require specific diagnosis and management. They are characterized by complex histopathologic criteria, large differences in secretory profile and évolutivity, and be associated to hereditary endocrine disease as NEM1 or VHL. Therapeutic strategy is currently discussed throught the regional or national pluridisciplinary workups organized by the 17 experts centers of the French RENATEN network. Treatment of these tumors requires the optimal control of hormonal secretory features for functioning neuroendocrine tumors while antiproliferative treatments are indicated for metastatic large or/and progressive tumors. Their optimal treatment may include locoregional procedures as chemoembolization, radiopeptidé therapy, chemotherapy, targeted therapies and clinical trials.

Non-secreting benign glucagonoma diagnosed incidentally in a patient with refractory thrombocytopenic thrombotic purpura: report of a case.

Thrombotic thrombocytopenic purpura (TTP) is a rare hematologic disorder, which may be idiopathic or secondary to a variety of diseases. However, there are very few reports of TTP in the context of pancreatic neoplasms. We report a case of relapsing TTP after initial treatment with plasmapheresis, corticosteroids, and rituximab, in a 59-year-old woman. During diagnostic work-up, a pancreatic lesion 35 × 25 mm in size was discovered incidentally and splenopancreatectomy was performed. The pathological diagnosis was benign glucagonoma. The hematological symptoms resolved completely after the procedure and 3 years later, the patient is well with no sign of recurrence of TTP or glucagonoma. To our knowledge, this represents the first documented case of a non-secreting benign pancreatic neuroendocrine tumor (glucagonoma) associated with TTP that is refractory to standard treatment.