Pancreatic tumors in multiple endocrine neoplasia type 1: Clinical presentation and surgical treatment

Among 33 patients with endocrine pancreatic tumors due to multiple endocrine neoplasia type 1 (MEN-1), 19 (58%) patients had hypergastrinemia, 7 (21%) patients had hyperinsulinism, and 7 (21%) patients had clinically non-functioning lesions. At least one gross tumor was found in all patients undergoing pancreatic surgery, including those with negative localization studies prior to operation. The patients also had additional macroscopic tumors as well as numerous microadenomas, and the lesions frequently were positive for immunostaining with multiple hormones, mainly pancreatic polypeptide, insulin, glucagon, and somatostatin. Duodenal endocrine lesions were found in 4 of 5 investigated patients and stained with gastrin and somatostatin antibodies. Distal, mainly subtotal pancreatic resection, was performed in 18 patients, eventually combined with caput tumor enucleation or duodenotomy, while a few patients underwent only tumor enucleation or a Whipple procedure. The long-erm outcome of operation was most favorable in patients with hyperinsulinism; only 1 patient had clinical recurrence. Patients with hypergastrinemia experienced only transitory lowering of serum gastrin values after pancreatic surgery and 47% of them had or developed metastases. Such tumor spread was seen in 57% of the patients with non-functioning lesions. Nine patients died from progressive tumor disease during follow-up. Consistent with previous studies, we found that surgery is indicated in MEN-1 patients with hyperinsulinism even if a lesion is not visualized by radiology. In addition, these indications should be extended to also include patients with only biochemical markers of disease, including elevations of gastrin, as these indicate the presence of gross tumors. This strategy should be applied especially in patients with aggressive family histories to possibly reduce the risk of malignant tumor progression.

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Resumen Entre 33 individuos con tumores pancréaticos endocrinos como componente del síndrome de neoplasia endocrina múltiple tipo 1 (NEM-1), 19 pacientes (58%) tenían hipergastrinemia, 7 (21%) hiperinsulinismo y 7 (21%) lesiones clínicas no funcionantes. En la totalidad de los pacientes sometidos a cirugía pancreática fue hallado por lo menos un tumor, incluso en aquellos con examenes de localización negativos anteriores a la operación. Estos pacientes también albergaban tumores macroscópicos, así como numerosos microadenomas; con frecuencia las lesiones demostraron inmunocoloración con diferentes hormonas, principalmente polipéptido, insulina, glucagón y somatostatina. Se encontraron lesiones endocrinas duodenales en 4 de cada 5 pacientes investigados, las cuales colorearon con gastrina y anticuerpos a la somatostatina. Se practicó resección pancreática distal (principalmente resección subtotal) en 18 pacientes, eventualmente combinada con enucleación del tumor (cuando éste se hallaba ubicado en la cabeza del páncreas) o duodenectomía; solamente unos pocos pacientes fueron sometidos a simple enucleación del tumor o al procedimiento de Whipple. El resultado a largo plazo fue más favorable en los pacientes con hiperinsulinismo, puesto que sólo uno presentó recurrencia clínica. Los pacientes con hipergastrinemia exhibieron apenas una disminución transitoria de los valores de gastrina sérica luego de la cirugía pancreática. Cuarenta y siete por ciento del conjunto tuvo o desarrolló metástasis, en tanto que la extensión local del tumor se presentó en 57% de los casos con lesiones no funcionantes. Nueve pacientes murieron por progresión de la neoplasia en el curso del seguimiento. En acuerdo con sugerencias previas, se considero quo la cirugía está indicada en pacientes con NEM-1 e hiperinsulinismo, aún en los casos en que no se visualiza radiológicamente la lesión, pero que la indicación puede ser ampliada para incluir también pacientes con sólo marcadores bioquímicos, tales como niveles elevados de gastrina, indicativos de la presencia de tumores macroscópicos. Esta estrategia debe ser aplicada principalmente en aquellos pacientes con historia familiar agresiva, con lo cual tal vez se reduce el riesgo de progesión maligna del tumor.

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Résumé Parmi 33 patients ayant une tumeur pancréatique endocrine due à une néoplasie endocrine multiple de type 1 (MEN-1), 19 (58%) avaient une hypergastrinémie, 7 (21%) un hyperinsulinisme et 7 (21%) une lésion cliniquement muette. On a mis en évidence au minimum une grosse tumeur chez tous les patients, y compris chez ceux dont les examens préopératoires de dépistage tumoral étaient négatifs. Les patients étaient également porteurs de tumeurs macroscopiques et de nombreux microadénomes. Les lésions montraient souvent un immunomarquage positif pour de multiples hormones, principalement le polypeptide pancréatique, l'insuline, le glucagon et la somatostatine. Des lésions endocrines duodénales furent retrouvées chez 4 des 5 patients explorés; elles montraient un immunomarquage avec les anticorps angigastrine et anti-somatostatine. Une résection pancréatique distale, le plus souvent subtotale, a été réalisée chez 18 patients. Elle était éventuellement complétée par une énucléation tmorale de la tête ou par une duodénotomie. Peu de patients ont bénéficié d'une simple énucléation ou d'une intervention de Whipple. L'évolution postopératoire à long terme a été plus favorable en cas d'insulinome puisque seul un patient a eu une récidive clinique. Les patients atteints de gastrinome n'ont présenté que transitoirement une diminution des taux sériques de gastrine après la chirurgie pancréatique. Quarante sept pour cent de ces patients avaient ou ont développé des métastases contre 57% des patients porteurs de lésions sans traduction clinique. Neuf patients sont décédés en raison de l'extension tumorale au cours du suivi. Conformément à des suggestions antérieures, la chirurgie semble indiquée chez les patients atteints de MEN-1 avec hyperinsulinisme même si la radiologie ne visualise pas de lésion. Mais cette indication peut être élargie aux patients dont seuls les paramètres biologiques sont en faveur d'une grosse tumeur (dont l'hypergastrinémie). Cette stratégie pourrait convenir particulièrement aux patients ayant des antécédents familiaux importants; elle permettrait peut-être de réduire le risque d'extension tumorale.

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Presented at the International Association of Endocrine Surgeons in Stockholm, Sweden, August, 1991.     

Method for Dissection of Mesenteric Metastases in Mid-gut Carcinoid Tumors

With adequate medical management the midgut carcinoid tumor generally is an indolent malignancy associated with substantial life expectancy and appreciable life quality, even in the presence of liver metastases and significant tumor burden. Abdominal complications may occur in this entity of carcinoids owing to entrapment of intestines and encasement of mesenteric vessels by mesenteric metastases and associated marked mesenteric fibrosis. This may be the cause of abdominal pain, disabling diarrhea, weight loss to the extent of malnutrition, and eventually the risk of death with acute or chronic intestinal obstruction or intestinal gangrene. Operative removal of the mesentericointestinal lesion is often indicated to prevent or treat these complications but may be technically difficult when mesenteric metastases extend in the vicinity of major vessels in the mesenteric root. At laparotomy 56 patients with advanced midgut carcinoids underwent removal of the mesenteric tumor with a method for preserving the mesenteric vessels. This was feasible by mobilizing and releasing the right colon and mesenteric root from posterior adhesions, identifying the mesenteric artery below the pancreas, and free-dissecting this artery on the tumor capsule in the mobilized mesentery. Dissection was successful even with tumors initially judged inoperable unless tumor growth completely surrounded the mesenteric vessels or extended retroperitoneally. One patient was subjected to distal intestinal artery bypass. Symptom relief was been substantial and often of long duration after mesenteric tumor removal in patients who prior to surgery often had threatening intestinal ischemia. Patients with advanced midgut carcinoids may benefit markedly from dissectional removal of mesenteric tumors, which (conceivably better than conventional wedge resection) preserves the length of the remaining intestine.     

Neuroprotective and symptomatological action of memantine relevant for alzheimer’s disease — a unified glutamatergic hypothesis on the mechanism of action

The involvement of glutamate mediated neurotoxicity in the pathogenesis of Alzheimer's disease is finding increasingly more acceptance in the scientific community. Central to this hypothesis is the assumption that in particular glutamate receptors of the N-methyl-D-aspartate (NMDA) type are overactivated in a tonic rather than a phasic manner. Such continuous mild activation leads under chronic conditions to neuronal damage. Moreover, one should consider that impairment of plasticity (learning) may result not only from neuronal damage per se but also from continuous activation of NMDA receptors. To investigate this possibility we tested whether overactivation of NMDA receptors using either non-toxic doses/concentrations of a direct NMDA agonist or through an indirect approach--decrease in magnesium concentration--produces deficits in plasticity. In fact NMDA both in vivo (passive avoidance test) and in vitro (LTP in CA1 region) impaired learning and synaptic plasticity. Under these conditions memantine which is an uncompetitive NMDA receptor antagonist with features of "improved magnesium" (voltage dependence, affinity) attenuated the deficit. The more direct proof that memantine can act as a surrogate for magnesium was obtained in LTP experiments under low magnesium conditions. In this case as well, impaired LTP was restored in the presence of therapeutically relevant concentrations of memantine (1 microM). In vivo, doses leading to similar brain/serum levels produce neuroprotection in animal models relevant for neurodegeneration in Alzheimer's disease such as neurotoxicity produced by inflammation in the NBM or beta-amyloid injection to the hippocampus. Hence, we postulate that if in Alzheimer's disease overactivation of NMDA receptors occurs indeed, memantine would be expected to improve both symptoms (cognition) and slow down disease progression because it takes over the physiological function of magnesium.     

The evaluation of Chronic Progressive External Ophthalmoplegia with computerized tomography

Introduction: Chronic progressiveexternal ophthalmoplegia is characterisedby limitation of ocular motility in alldirections of gaze and ptosis.Innervational or myogenic factors wereclaimed to be responsible for thismotility disorder. The aim of thisstudy was toinvestigate the extraocular muscles inCPEO with computerized tomography in an attemptto distinguish extraocular musclemorphology caused by this disorderfrom that occurring in normal individuals.Methods: Eighteen orbits from 9patients diagnosed with CPEOwere included in the study. Axialand coronal scans were obtained for CTevaluation of extraocular muscles and thedimensions of extraocular muscles were measured.The control group consisted of40 orbits belonging to 20 individuals and,the results were compared with a student'st test.Results: The thickness (the verticaldimension of vertical recti and thehorizontal dimension of horizontal recti)of all rectus muscles wassignificantly decreased in comparison with the controlgroup, whereas the width (the horizontal dimensionof vertical recti and the verticaldimension of horizontal recti) was similar inboth the diseased and normal orbits.In all the rectus musclesof the diseased orbits,the normal fusiform shape was lost and the muscles appeared asthin bands.Discussion: The differentiation ofCPEO from other myogenic and neurogenicdisorders may present difficulty,and a cluster of criteria are required fora final diagnosis. CT has provento be a valuable tool in assessing extraocularmuscles [1, 2]. In this study, an extremeatrophy of all rectus muscles wasdemonstrated by means of CT. This diagnostic method mayconsequently contribute to a properdiagnosis of CPEO.     

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