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Insulinoma.
Pol Merkur Lekarski. 2007
Jan;22(127):70-4.
Insulinoma is
considered the most common endocrine tumour of the pancreas with an
annual prevalence of 4 cases per million people. Contrary to the other
endocrine tumours of this organ, over 90% of the insulinomas are
benign in nature. The clinical presentation of this neoplasm depends
on excessive production of insulin and pro-insulin and is
characterised by the symptoms of neuroglycopenia and catecholamine
response. Effective management requires directed biochemical testing,
careful choice of preoperative imaging tests, and complete pancreatic
exploration by an experienced endocrine surgeon utilising
intraoperative ultrasound. The only curative treatment for insulinoma
is complete resection of the tumour. The aim of this paper is to
critically discuss contemporary diagnosis and treatment of this
neoplasm on the basis of progress made in recent years.
Recurrent
hyperinsulinemic hypoglycemia caused by an insulin-secreting
insulinoma.Nat
Clin Pract Endocrinol Metab. 2006
Aug;2(8):467-70.
BACKGROUND: A
37-year-old woman presented to her local physician in 1995 for
evaluation of episodes of neuroglycopenia, which manifested as visual
distortion and withdrawal without response to verbal commands in the
food-deprived state. A 72 h fast was positive for hypoglycemia and the
patient was given diazoxide and prednisone, but hypoglycemia was not
controlled. The patient underwent pancreatic exploration in 1997, but
no insulinoma was found. She was referred to the Mayo Clinic in 1998
for further evaluation and treatment. Abdominal CT and transabdominal
ultrasound revealed a 1 cm insulinoma in the uncinate process of the
pancreas. The patient again underwent pancreatic exploration. The
insulinoma was removed, but during enucleation the tumor fractured.
Hypoglycemia recurred 6 months later. INVESTIGATIONS: Laboratory
tests, transabdominal ultrasound CT of the pancreas, endoscopic
ultrasonography, fine-needle aspiration, and pancreatic exploration.
DIAGNOSIS: Recurrence of hyperinsulinemic hypoglycemia caused by
fracture of an insulin-secreting insulinoma. MANAGEMENT: Surgical
excision of the recurrent tumor.
Missed
hyperinsulinaemia in a patient with an insulinoma.Ned
Tijdschr Geneeskd. 2005 Apr
23;149(17):944-6.
In a
57-year-old man with symptomatic hypoglycaemias which gave cause to
suspect an insulinoma, normal insulin levels were initially found. A
repeated fasting assay at another hospital did, however, reveal the
expected hyperinsulinaemia. Scans revealed an abnormality in the
pancreas. After surgical removal of the insulin-producing tumour the
patient made a quick recovery. The diagnosis of organic
hyperinsulinaemia is established by demonstrating inappropriately high
serum-insulin concentrations during fasting hypoglycaemia. The
diagnostic normative values are based on the classic polyclonal method
of determination. This new highly-specific insulin assay has no
cross-reactivity with pro-insulin, which is often produced
disproportionately more by an insulinoma. As a result of this
false-normal insulin values are found. Therefore new normative values
are needed for the newer insulin assays when diagnosing an
insulin-producing islet cell tumour. Pro-insulin and C-peptide assays
may play a useful role in this.
Insulinoma.
Best Pract Res Clin Gastroenterol. 2005
Oct;19(5):783-98.
Although rare,
insulinomas are the most common functioning islet cell tumour of the
pancreas. Recognition of the key neuroglycopenic symptoms should
trigger the initial investigation. Biochemical proof of endogenous
hyperinsulinemic hypoglycemia establishes the diagnosis. Several
options are available for imaging and localizing these tumours
including ultrasonography, computed tomography, and intra-arterial
calcium stimulation with venous sampling. The tumours are usually
small, single, benign, well-circumscribed, and evenly distributed
throughout the pancreas. This tumour may be a part of the multiple
endocrine neoplasia type 1 (MEN-1) syndrome, in which case the tumours
are almost always multiple. Surgical treatment is the only curative
method, traditionally accomplished with enucleation or partial
pancreatic resection. Patients are almost invariably cured lifelong
with complete excision of a benign insulinoma. The most recent
developments in this area are the recognition of noninsulinoma
pancreatogenous hypoglycemia syndrome as a cause of organic
hypoglycemia, and the development of laparoscopic techniques to excise
these tumours.
The surgical
management of insulinoma.Bol
Asoc Med P R. 2004 Jan-Feb;96(1):33-8.
Insulinoma is
the most common endocrine tumor of the pancreas. Over 90% of the
insulinomas are benign and single, and can be cured by simple
excision. Depending on the location, insulinomas can be enucleated,
might require partial or distal pancreatectomy or
pancreaticoduodenectomy. Five cases with insulinoma successfully
treated by surgical intervention, two by enuclation, two by distal
pancreatectomy and splenectomy, and preservation of the spleen have
been summarized. The management of insulinoma involves the diagnosis,
localization of the tumor and treatment. Insulinomas are rare tumors
of the pancreas. Nevertheless, it is the most common endocrine tumor
of the pancreas. Specifically arising from the beta cells, of the
islets of Langerham, that produce insulin (fig.1). Its incidence is
one in 250,000 inhabitants. It can be seen at any age, but is more
frequent in females between 4 and 82 years of age, with a mean of 45.5
years. Insulinomas are evenly distributed between the head, body and
tail of the pancreas. Over 90% are benign and single and can be cured
by simple excision. Depending on the location insulinomas can be
enucleated, might require partial or distal pancreatectomy or a
pancreaticoduodenectomy. Ten percent could be malignant when
metastasis to peripancreatic lymph nodes or to the liver is detected.
The course of the patient with malignant insulinoma is an indolent
one. The release of insulin leads to fasting hypoglycemia producing
confusion, loss of consciousness, coma or convulsions. The
hypoglycemia in turn can induce the release of cathecolamines
producing tachycardia, tremulousness and diaphoresis. The Whipple's
triad must be present for the diagnosis of insulinoma; symptoms of
hypoglycemia, glucose level below 50 mgs/dl and relief of symptoms by
the administration of glucose. In large series the interval between
the onset of symptoms and a definitive diagnosis of insulinoma was 37
months, with a range of 0 to 14 years.
Review of
eight cases of insulinoma.East
Afr Med J. 2002 Jul;79(7):368-72.
OBJECTIVE: To
review patients records operated with the diagnosis of insulinoma and
to discuss their clinical presentations, diagnostic and therapeutic
modalities. DESIGN: Retrospective study. SETTING: Ankara Numune
Teaching and Research Hospital, Turkey. SUBJECTS: Eight cases were
operated in the Department of 6th Surgery, Ankara Numune Teaching and
Research Hospital between 1994 and 2000. All patients had
neuroglycopenic symptoms. Six patients had blood glucose levels of
lower than 50 mg/dL during the admission. The other two patients had
hypoglycaemia in the prolonged fasting test. Serum insulin/glucose
ratio was diagnostic in all patients except one. Abdominal
ultrasonography and computerised tomography could successfully
localise the tumour in one case. In six patients tumours could be
localised by endoscopic pancreatic ultrasonography. In one patient
none of the studies could localise the tumour. Three tumours were
located at the pancreatic head, one in the neck, two at the body and
two at the tail. All tumours except one were palpable. Enucleation was
the procedure of choice in four cases and distal pancreatectomy was
the procedure of choice in four. RESULTS: Post-operative course was
uneventful in seven patients. One patient died due to intra-abdominal
sepsis. Hypoglycaemia was controlled in all patients after the
surgery. CONCLUSION: Surgery is the mainstay of treatment of
insulinoma. Enucleation should be the procedure of choice if possible.
Endoscopic pancreatic ultrasonography has promising results and may
replace invasive angiographic studies in the future.
Insulinoma in
pregnancy: a case report and review of the literature.Obstet
Gynecol Surv. 2002 Apr;57(4):229-35.
Insulinomas
are rare tumors with an incidence of approximately four cases per
million person-years. Nineteen cases of insulinoma during pregnancy
have been reported. Hypoglycemic symptoms usually appear during the
first trimester. A 28-year-old primigravida was admitted at 6 weeks of
gestation after referral for uncontrolled seizures. Her previous
seizure work-up included a normal EEG and a normal magnetic resonance
imaging of the brain. Elevated fasting insulin and C-peptide levels
accompanied severe hypoglycemia. The patient was managed with glucose
monitoring, frequent small meals, and rare doses of glucagon.
Postpartum testing was consistent with insulinoma, and magnetic
resonance imaging indicated a mass in the tail of the pancreas. During
surgical exploration with intraoperative ultrasound, two insulinomas
were removed from the tail of the pancreas. The hypoglycemic episodes
resolved and the fasting glucose levels normalized. Insulinomas are
rare in pregnancy and can be difficult to diagnose. Symptoms may
resolve during the second and third trimesters, possibly due to
changes in glucose metabolism associated with pregnancy. Misdiagnosis
has been fatal. Careful management during pregnancy and aggressive
treatment after delivery are essential. TARGET AUDIENCE: Obstetricians
and Gynecologists, Family Physicians. LEARNING OBJECTIVES: After
completion of this article, the reader will be able to describe the
pathophysiology of an insulinoma, to list the potential tests used to
make the diagnosis of insulinoma, and to outline potential treatment
options for a patient with an insulinoma.
Surgical treatment
and outcome in insulinoma.Zentralbl
Chir. 2001 Apr;126(4):273-8.
In the therapy
of organic hyperinsulinism, interest is mainly focussed on the
surgical removal of the hyperactive tissue. In spite of these
progresses, the surgical treatment is not devoid of problems. These
comprise the primary untraceable insulinoma, multiple insulinomas,
nesidioblastosis and reoperation. The development of laparoscopic
surgery leads to new opportunities the rating of which must be
defined. Solitary adenomas are causal for primary hyperinsulinism in
80% to 90% of cases. Intraoperative 87.5% of the tumors are palpable
and 83% are detectable by ultrasound. By combination of both methods
it is possible to remove 97% of the solitary tumors. Occult adenomas,
which cannot be represented by preoperative imaging diagnostics are
detectable through intraoperative methods in over 80% of cases by
palpation or ultrasound respectively. By combination of both methods,
97% of these occult adenomas can be removed. This reliability of the
intraoperative detection makes the preoperative localizing diagnostics
unnecessary if no MEN-syndrome is present. If a MEN-syndrome is
present, multiple adenomas are common. In 60% of cases multiple
adenomas are responsible for the persistency of the syndrome after an
unsuccessful primary operation. Therefore a preoperative localizing
diagnostics is advisable in case of a MEN-syndrome. Multiple adenomas
are treated by left-pancreatic resection with enucleation of remaining
adenomas in the pancreatic head region. In case of an untraceable
adenoma, the possibility of the rare nesidioblastosis should be
considered. This rare occurrence can be detected by fresh frozen
sectioning. The resection of 75% to 80% of the pancreas is
recommended. The attempt of a laparoscopic removal of solitary
adenomas may be indicated, taking into account all contraindications.
The preliminary requisite for this is an experienced center in
endocrine surgery as well as an experienced laparoscopic surgeon.
Contraindications for the laparoscopic procedure are: a tumor
localized in the head of the pancreas or in the dorsal parts of the
organ, multiple adenomas and nesidioblastosis. In case of occult
adenomas, laparoscopic therapy is problematic, as they are also
difficult to detect intraoperatively through laparoscopy. The
incidence of postoperative complications is still high with 30% and a
mortality of 2%. Most often pancreatic fistulas (10%) and septic
complications were seen.
Rational
preoperative diagnosis of insulinoma.Chirurg.
1999;70(3):298-301.
An insulinoma
is the most common pancreatic endocrine tumor. Typical is the presence
of a solitary tumor. In 10% of the cases an insulinoma may occur in
multiple sites, especially in MEN syndrome. Malignant insulinomas
appear in 10% of cases. Insulinomas occur at every age, but mainly
about the 50th year. Because of its small size (a diameter of 1-2 cm)
diagnostic localization is often difficult. With costly imaging
techniques such as CT and MRI, only 60% of the adenomas can be
detected preoperatively. If reoperation is a possibility, CT and MRI
are advisable. Based on our own experience and the reports of other
authors, we advise the combination of transabdominal ultrasound and
endosonography for the primary operation. With these methods 90% of
the adenomas can be localized preoperatively. If the clinical and
biochemical insulinoma diagnosis is definite, explorative laparotomy
is indicated even without preoperative morphological tumor detection.
With intraoperative ultrasound and systematic palpation more than 97%
of insulinomas can be found and resected. We report the case of a
54-year-old woman with unsuccessful preoperative localization in spite
of extensive clinical, biochemical and imaging procedures over a
6-month period.
Insulinoma.
Surg Oncol Clin N Am. 1998
Oct;7(4):819-44.
Symptoms most
characteristically diagnostic of insulinoma are those of
neuroglycopenia. The combination of hypoglycemia and endogenous
hyperinsulinemia are pathognomonic of insulinoma. Several localization
techniques are available, the choice of which best depends on the best
expertise at individual institutions. Intraoperative ultrasonography
is helpful in localization and defining related anatomy. Enucleation
of these intrapancreatic tumors is preferred, but for body and tail
lesions, distal pancreatic resection may be required. Because at least
90% are benign, long-term cure with complete resolution of
preoperative symptoms is expected.
Insulinoma--experience
from 1950 to 1995.West
J Med. 1998 Aug;169(2):98-104.
Insulinomas
are rare tumors that originate from the islet cells of the pancreas.
The purpose of this study was to analyze our experience in patients
with insulinoma and present our approach to these patients. Medical
records of 67 patients treated at the University of California, San
Francisco (UCSF) Medical Center, 56 surgically and 11 medically, from
1954 to 1995 were retrospectively reviewed. Presenting symptoms,
physical findings, laboratory data, pre and intraoperative
localization studies, operative management, operative success, and
post-operative complications were analyzed. Among the entire cohort,
there were 11 patients with Multiple Endocrine Neoplasia type I (MEN
1) and 7 patients with multiple tumors. 46 out of 48 patients (96%)
having first operations for benign tumors and 5 out of 8 patients
(63%) having reoperations for benign tumors were successful, as were 6
out of 12 patients (50%) having operations for islet cell carcinoma.
Overall, preoperative localization studies were positive in only 46%
of patients and therefore failed to improve our surgical outcome.
Careful palpation with intraoperative ultrasonography gave the best
localization results. Enucleation of solitary tumors is curative in
sporadic cases and gives the lowest complication rate. In patients
with MEN 1, subtotal pancreatectomy with enucleation of tumours from
the pancreatic head and uncinate process is recommended over simple
enucleation because of frequent multiple tumors.
Special
diagnostic and therapeutic aspects of insulinoma.Chirurg.
1997 Feb;68(2):116-21.
Insulinomas
are rare tumors and account for 90% of all endocrine pancreatic
tumors. They typically present as a solitary tumor, but may occur in
multiple sites (e.g. multiple endocrine neoplasia type I) or as a
malignant disease in 10% of cases and rarely as nesidioblastosis or
islet cell adenomatosis. Neuroglucopenic symptoms lead to the
diagnosis; inadequate high insulin and C-peptide secretion with
hypoglycemia in the fasting test confirm the diagnosis. Preoperative
localization is not necessary prior to the first operation. The
standard operation is enucleation, or depending on size and location,
resection. The treatment of multiple tumors and islet cell hyperplasia
with a high risk of recurrence is problematic. Subtotal resection plus
enucleation seems to be better than selective tumor resection. In
malignant insulinomas, mostly presenting with liver metastases,
aggressive surgical therapy with hepatectomy and debulking,
chemoembolization and systemic chemotherapy are the modalities of
choice.
Insulinoma.
Clinical and surgical considerations concerning a case.Minerva
Chir. 1997 Mar;52(3):289-93.
Insulinoma is the most common endocrine tumor of the pancreas. It
arises from the beta-islet cells of Langerhans. Insulinomas synthesize
and secrete insulin autonomously in the presence of low blood glucose
levels, causing spontaneous hypoglycemia and characteristic clinical
symptoms. The authors examined data the from the most important
international research projects on this topic during the past 20
years. Insulinomas are rare, with an annual incidence of 0.5 per
million population. Up to 90% patients have benign solitary pancreatic
insulinomas. People of all ages can be affected with this neoplasm.
The authors reported a case of a large insulinoma of the body and tail
of the pancreas, with atypical psychic symptoms. A distal
pancreatectomy with splenectomy was performed. No surgical
complications occurred in the postoperative course. The psychic
symptoms were emphasized with refusal of food. The patient underwent
Parenteral Nutrition and was discharged 24 days after the operation.
The surgical removal of the tumor permitted the patient to recover
completely, with glucose and insulin blood levels in normal range.
Gastrointestinal endocrine tumours. Insulinoma.Baillieres
Clin Gastroenterol. 1996
Dec;10(4):645-71.
Fundamental to
establishing a diagnosis of insulinoma is first to consider the
diagnosis when presented with the constellation of symptoms and signs
that indicate hypoglycaemia. Prominent and most convincing are
manifestations of neuroglycopenia. Although hypoglycaemia can be
caused by a number of disorders, the combination of hypoglycaemia and
endogenous hyperinsulinaemia is diagnostic of insulinoma. Our criteria
now include a glucose level of 40 mg/dl with a concomitant insulin
level of 6 microU/ml, a C-peptide level exceeding 200 pmol/l, and
negative screen for sulphonlyurea. Ancillary diagnostic tests or the
use of insulin surrogates may offer helpful confirmation. Localization
is still evolving, but in our hands pre-operative ultrasound is the
best and only pre-operative test that we obtain in the usual
situation. Expertise and experience with other modalities at other
institutions offer reasonable but more costly alternatives.
Intraoperative ultrasonography provides significant benefit in both
tumour localization and delineating important related anatomy.
Insulinomas are virtually all located in the pancreas; 90% are benign,
single, and are generally firmer than surrounding normal pancreas.
Extensive exposure may be required to identify and remove safely the
tumour. Enucleation is our preferred technique, but distal
pancreatectomy for tumours in the body or tail is an excellent method
as well. Pancreatoduodenectomy is rarely necessary. Complications most
commonly relate to leak of pancreatic secretions, causing pseudocyst,
abscess, or fistula. except in MEN 1 syndrome, excision of a benign
insulinoma equates with disease cure, and patients are often
extraordinarily grateful as the change in their lives may be profound.
Insulinoma: 31
years of tumor localization and excision.J
Surg Oncol. 1988 Dec;39(4):274-8.
This report is
based on 31 years of experience with 116 cases of hyperinsulinism. Six
cases had hypertrophy of the islets of Langerhans, 3 had widespead
metastasis from malignant insulinomas, and 107 were benign adenoma
cases. An immunoreactive insulin to glucose ratio of 0.3 of the
peripheral venous blood before operation is of great value in
diagnosing hyperinsulinism. Intraoperatively, immunoreactive insulin
assay of the portal blood (IRI) is very valuable in determining if an
insulinoma remains. The dividing line is 100 microU.ml-1. In
localizing the tumor, "differential" PTPC is important before
operation. During the operation, fine needle aspiration cytology may
assist in ascertaining if the palpable tumor is an insulinoma.
Multiple fine needle aspiration cytology examinations can sometimes
reveal an insulinoma in an indurated pancreas. Portal vein blood IRI
and blood sugar assays may serve to confirm if removal of the
insulinoma is complete. Removal of the insulinoma controls
hypoglycemia satisfactorily, but the brain damage incurred by
prolonged hypoglycemia cannot be significantly altered. Removal of the
tumor should be by enucleation, and the raw surface of the pancreas
should be drained not sutured.
Recently
experienced ten cases of insulinoma--preoperative diagnosis of
localization and intraoperative simultaneous monitoring of glucose and
insulin. Nippon
Geka Gakkai Zasshi. 1988
Mar;89(3):398-407.
We have
experienced 10 cases of insulinoma during the last 10 years from 1977
to 1986. All cases had strong hypoglycemic symptoms such as
disturbance of consciousness, and insulinoma still tended to be
misdiagnosed as epilepsy. The diagnosis of insulinoma was easily
available from serum IRI (immunoreactive insulin)/plasma glucose ratio
in all of the ten cases. As preoperative procedures for the diagnosis
of localization, arteriography, computed tomography and portal blood
sampling were positive in 6 of 8, 4 of 6 and 2 of 2 patients,
respectively. At operation, all insulinomas could be identified by
digital palpation. We performed simple excision of the tumor in 6
patients and distal pancreatectomy in 4 patients. The tumors were
solitary and benign in all patients, ranging in size from 1.0 cm to
4.5 cm. Three cases were presented as case reports. In these cases,
portal blood sampling and/or intraoperative monitoring of plasma
glucose and serum IRI were performed. Portal blood sampling was
effective even for a case which was negative in image diagnostic
procedures. Furthermore, simultaneous monitoring of plasma glucose and
serum IRI by quick radioimmunoassay seemed to be a good guide to the
completeness of resection of insulin producing tumors.
Insulinoma:
the value of intraoperative ultrasonography.Wien
Klin Wochenschr. 1988 May
27;100(11):376-80.
Ideally,
surgical exploration for insulinomas would be met with uniform success
in both finding and removing the tumor, incurring no postoperative
mortality or morbidity. In reality, however, insulinomas remain
undetected by even experienced surgeons in 10 to 20% of patients,
including present-day series. Additionally, postoperative
complications may occur in 10 to 25% of patients, principally related
to the pancreatic dissection. Although dispensing with any attempt to
preoperatively localize the tumor has been advocated, most authors
agree that localization efforts are necessary and helpful. To review
the results and surgical implications of current localization
techniques, 41 adult patients who were surgically treated for
insulinomas at the Mayo Clinic from 1980 through June 1987, were
reviewed. Tumor size ranged from 5 mm to 4 cm, and the sensitivity of
tumor localization using arteriography, computed tomography,
preoperative and intraoperative ultrasonography were 55%, 27%, 59%,
and 90%, respectively. Since the introduction of intraoperative
ultrasonography into our clinical practice in 1982, all 29 of our
adult patients' insulinomas have been identified with a combination of
this technique and palpation by an experienced surgeon. There were no
false positive interpretations with intraoperative ultrasonography,
and tumors were imaged in four patients that were not palpable. In 18
of these 29 (62%) patients, the information gleaned from the images
appeared to influence the surgical management. While there is no
substitute for exploration by an experienced surgeon, his ability is
enhanced by the addition of both preoperative and intraoperative
ultrasonography.
Insulinoma:
critical study of methods of localization and strategy.Ann
Endocrinol (Paris). 1985;46(6):383-7.
In patients
with proven hyperinsulinism, localization of the underlying insulinoma
may be difficult. The localization diagnosis may be performed
preoperatively using different procedures, such as ultrasonography,
computed tomography, selective arteriography of the pancreatic vessels
and percutaneous transhepatic blood sampling in the portal venous
system. At operation, insulinomas may be detected by inspection and
bidigital palpation, pancreatico-sonography and rapid determination of
insulin concentration after sampling of blood in pancreatic veins. By
discussing the advantages and disadvantages of each localization
procedure, the authors propose a strategy fort the detection of
pancreatic insulinomas.
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