In vivo imaging of GLP-1R with a targeted bimodal PET/fluorescence imaging agent.

Accurate visualization and quantification of ß-cell mass is critical for the improved understanding, diagnosis, and treatment of both type 1 diabetes (T1D) and insulinoma. Here, we describe the synthesis of a bimodal imaging probe (PET/fluorescence) for imaging GLP-1R expression in the pancreas and in pancreatic islet cell tumors. The conjugation of a bimodal imaging tag containing a near-infrared fluorescent dye, and the copper chelator sarcophagine to the GLP-1R targeting peptide exendin-4 provided the basis for the bimodal imaging probe. Conjugation was performed via a novel sequential one-pot synthetic procedure including (64)Cu radiolabeling and copper-catalyzed click-conjugation. The bimodal imaging agent (64)Cu-E4-Fl was synthesized in good radiochemical yield and specific activity (RCY = 36%, specific activity: 141 µCi/µg, >98% radiochemical purity). The agent showed good performance in vivo and ex vivo, visualizing small xenografts (<2 mm) with PET and pancreatic ß-cell mass by phosphor autoradiography. Using the fluorescent properties of the probe, we were able to detect individual pancreatic islets, confirming specific binding to GLP-1R and surpassing the sensitivity of the radioactive label. The use of bimodal PET/fluorescent imaging probes is promising for preoperative imaging and fluorescence-assisted analysis of patient tissues. We believe that our procedure could become relevant as a protocol for the development of bimodal imaging agents.

[Diagnosis and treatment of 51 patients with pancreatic islet cell tumors].

OBJECTIVE: To investigate the diagnosis and treatment of pancreatic islet cell tumors. METHODS: Fifty-one patients with islet cell tumors treated in our department from January 1991 to April 2011 were included in this study. The data of clinical features, diagnosis and treatment were retrospectively analyzed. RESULTS: Among the 51 cases, 38 cases showed typical Whipple's triad, and the other 13 cases were non-functional islet cell tumors. In these 13 cases, 5 patients had no specific clinical symptoms, and 8 patients had abdominal distending pain. The positive rates of imaging were: B-ultrasound 43.1%, multi-slice spiral CT 69.8%; MRI 62.5%, endoscopic ultrasonography (EUS) 64.7% (11/17), and intraoperative ultrasound (IOUS) 96.3%, the differences among them were statistically significant (P<0.05). All patients underwent surgical treatment. Postoperative pancreatic leakage happened in 6 cases. Finally all the patients recovered after effective external drainage, anti-infection treatment and nutritional support. CONCLUSIONS: Intraoperative ultrasonography (IOUS) has a higher accuracy in the diagnosis of pancreatic islet cell tumors, compared with preoperative B-ultrasonography, CT, MRI, and endoscopic ultrasound (EUS). The most effective treatment of this disease is surgery.

Pancreatic neuroendocrine tumors: radiographic calcifications correlate with grade and metastasis.

BACKGROUND: Studies to identify preoperative prognostic variables for pancreatic neuroendocrine tumor (PNET) have been inconclusive. Specifically, the prevalence and prognostic significance of radiographic calcifications in these tumors remains unclear. METHODS: From 1998 to 2009, a total of 110 patients with well-differentiated PNET underwent surgical resection at our institution. Synchronous liver metastases present in 31 patients (28%) were addressed surgically with curative intent. Patients with high-grade PNET were excluded. The presence of calcifications in the primary tumor on preoperative computed tomography was recorded and correlated with clinicopathologic variables and overall survival. RESULTS: Calcifications were present in 16% of patients and were more common in gastrinomas and glucagonomas (50%), but never encountered in insulinomas. Calcified tumors were larger (median size 4.5 vs. 2.3 cm, P=0.04) and more commonly associated with lymph node metastasis (75 vs. 35%, P=0.01), synchronous liver metastasis (62 vs. 21%, P<0.01), and intermediate tumor grade (80 vs. 31%, P<0.01). On multivariate analysis of factors available preoperatively, calcifications (P=0.01) and size (P<0.01) remained independent predictors of lymph node metastasis. Overall survival after resection was significantly worse in the presence of synchronous liver metastasis (5-year, 64 vs. 86%, P=0.04), but not in the presence of radiographic calcifications. CONCLUSIONS: Calcifications on preoperative computed tomography correlate with intermediate grade and lymph node metastasis in well-differentiated PNET. This information is available preoperatively and supports the routine dissection of regional lymph nodes through formal pancreatectomy rather than enucleation in calcified PNET.

Investigating difficult to detect pancreatic lesions: Characterization of benign pancreatic islet cell tumors using multiparametric pancreatic 3-T MRI.

INTRODUCTION: Pancreatic islet-cell tumors (PICT) often present with atypical signal-characteristics and are often missed on preoperative imaging. The aim of this study is to provide a multiparametric PICT characterization and investigate factors impeding PICT detection. MATERIAL AND METHODS: This is a detailed MRI analysis of a prospective, monocenter study, including 49 consecutive patients (37 female, 12 male; median age 50) with symptoms due to endogenous hyperinsulinemic hypoglycemia (EHH) and mostly negative prior-imaging. All patients received a 3-T MRI and a 68Ga-DOTA-exendin-4-PET/CT. Pooled accuracy, sensitivity, specificity and inter-reader agreement were calculated. Reference-standard was histopathology and 68Ga-DOTA-Exendin-4-PET/CT in one patient who refused surgery. For PICT analyses, 34 patients with 49 PICTs (48 histologically proven; one 68Ga-DOTA-exendin-4-PET/CT positive) were assessed. Dynamic contrast-enhanced (DCE) Magnetic Resonance Images (MRI) with Golden-Angle-Radial-Sparse-Parallel (GRASP) reconstruction, enabling imaging at high spatial and temporal resolution, was used to assess enhancement-patterns of PICTs. Tumor-to-background (T2B) ratio for each sequence and the employed quantitative threshold for conspicuity of PICTs were analyzed in regard to prediction of true-positive PICTs. RESULTS: Evaluation of 49 patients revealed a pooled lesion-based accuracy, sensitivity and specificity of 70.3%, 72.9% and 62.5%, respectively. Mean PICT size was 12.9±5.3mm for detected, 9.0±2.9mm for undetected PICTs (p-value 0.0112). In-phase T1w detected the most PICT (67.3%). Depending on the sequence, PICTs were isointense and poorly visible in 29-68%. Only 2/41(4.9%) PICTs showed typical signal-characteristics across T1w, T2w, DWI and ceT1w combined. 66.6% of PICTs enhanced simultaneously to the parenchyma, 17.8% early and 15.6% late. Predictor screening analysis showed number of sequences detecting a PICT, lesion size and in-phase T1w T2B ratio had the highest contribution for detecting a true-positive PICT. CONCLUSION: The majority of PICTs enhance simultaneously to surrounding parenchyma, present with atypical signal-characteristics and thus are poorly visible. In non-enhancing PICTs, radiologists should search for small lesions most likely conspicuous on unenhanced T1w or DWI.

Usefulness of EUS combined with contrast-enhancement in the differential diagnosis of malignant versus benign and preoperative localization of pancreatic endocrine tumors.

BACKGROUND: Pancreatic endocrine tumors (PETs) develop in relatively few patients, but they are often difficult to diagnose because of their small size and various clinical symptoms. OBJECTIVE: The aim of this study was to investigate the usefulness of EUS combined with contrast enhancement (CE-EUS) in the preoperative localization of PETs and the differentiation between malignant and benign PETs. DESIGN AND SETTING: Single-center retrospective study. PATIENTS: Sixty-two pathologically certified PETs of 41 patients who underwent EUS, multiphasic multidetector computed tomography (MDCT), and transabdominal US at our institute since 2001. INTERVENTIONS: Intravenous injection of US contrast media. MAIN OUTCOME MEASUREMENTS: Comparison of EUS, MDCT, and US in the preoperative identification of PETs, and the characteristic findings of EUS with malignancy. RESULTS: EUS showed high sensitivity (95.1%) in identifying PETs compared with MDCT (80.6%) and US (45.2%). Multivariable logistic regression analysis showed that heterogeneous ultrasonographic texture was the most significant factor for malignancy (OR = 53.33; 95% CI, 10.79-263.58). Most heterogeneous hypoechoic areas and anechoic areas corresponded to hemorrhage or necrosis on pathologic examination. They were identified as filling defects in CE-EUS and were more clearly recognized than in conventional EUS. LIMITATIONS: Retrospective study. CONCLUSION: EUS has higher sensitivity in preoperative localization of PETs compared with MDCT and US. The characteristics of EUS and CE-EUS findings in malignant PETs were clarified, and they will improve the diagnostic accuracy of PETs.

6-L-18F-fluorodihydroxyphenylalanine PET in neuroendocrine tumors: basic aspects and emerging clinical applications.

In recent years, 6-l-18F-fluorodihydroxyphenylalanine (18F-DOPA) PET has emerged as a new diagnostic tool for the imaging of neuroendocrine tumors. This application is based on the unique property of neuroendocrine tumors to produce and secrete various substances, a process that requires the uptake of metabolic precursors, which leads to the uptake of 18F-DOPA. This nonsystematic review first describes basic aspects of 18F-DOPA imaging, including radiosynthesis, factors involved in tracer uptake, and various aspects of metabolism and imaging. Subsequently, this review provides an overview of current clinical applications in neuroendocrine tumors, including carcinoid tumors, pancreatic islet cell tumors, pheochromocytoma, paraganglioma, medullary thyroid cancer, hyperinsulinism, and various other clinical entities. The application of PET/CT in carcinoid tumors has unsurpassed sensitivity. In medullary thyroid cancer, pheochromocytoma, and hyperinsulinism, results are also excellent and contribute significantly to clinical management. In the remaining conditions, the initial experience with 18F-DOPA PET indicates that it seems to be less valuable, but further study is required.

Comments and illustrations regarding the guidelines and good clinical practice recommendations for contrast-enhanced ultrasound (CEUS)--update 2008.

The recently published EFSUMB guidelines and recommendations provide general advice for the use of ultrasound contrast agents to improve the management of patients. They are the subject of this pictorial essay, comments and analysis of the literature. CEUS has become the most important imaging method for focal liver diseases. Its uses are discussed in detail, especially the characterization of liver tumors and the monitoring of local treatment. The recommendations also deal with the uses of ultrasound contrast agents for the evaluation of the microvasculature and macrovasculature of the kidneys, including the characterization of focal renal lesions, the detection of lesions and the monitoring of local treatment. CEUS and contrast-enhanced endoscopic ultrasound can be used to characterize lesions. Ductal adenocarcinoma as the most common tumor of the pancreas is typically hypoenhanced compared to the adjacent pancreatic tissue in all phases. Neuroendocrine tumors and serous microcystic adenoma of the pancreas are characterized by hypervascularization appearing typically hyperenhanced during CEUS. This is of importance for a differential diagnosis. Vesicoureteric reflux and blunt abdominal trauma are also mentioned. Other parts or chapters of the guidelines are described in a separate paper of this supplement.

Central pancreatectomy: a technique for the resection of pancreatic neck lesions.

HYPOTHESIS: Central pancreatectomy has been used sparingly because the spectrum of indications is quite narrow. Although historically used for traumatic pancreatic transection and chronic pancreatitis, it currently is reserved for selective management of pancreatic neck lesions that are benign or have low malignant potential. Varying morbidity rates have been published in the literature. Our objectives were to describe the technique and determine the safety and effectiveness of central pancreatectomy in the excision of benign or low-malignant potential lesions of the pancreatic neck. DESIGN: Retrospective clinicopathologic data review. SETTING: The Mayo Clinic surgical index was used to identify procedures matched for central, median, middle, or middle segment pancreatectomy. PATIENTS: Eight patients (4 men, 4 women) underwent central pancreatectomy between 1998 and 2004. INTERVENTION: Patients with pancreatic neck or proximal body masses underwent central pancreatectomy at the Mayo Clinic, Rochester, Minn. MAIN OUTCOME MEASURES: Patients were followed up closely for postoperative complications during the initial hospital admission. On follow-up, long-term endocrine and exocrine function were determined based on laboratory values and patient history. RESULTS: Abnormalities included 3 islet cell tumors, 2 serous cystadenomas, a mucinous cystadenoma, a lymphoepithelial cyst, and a recurrent liposarcoma. Mean tumor size was 2.8 cm and mean operative time was 4.8 hours with a mean blood loss of 381 mL. The most common complication was pancreatic leak (5 patients [63%]). Reoperation was necessary in 2 patients (25%), both secondary to hemorrhage. There was no mortality or new-onset diabetes mellitus. One patient transiently required oral pancreatic enzyme supplementation. CONCLUSIONS: Central pancreatectomy may preserve endocrine and exocrine function. While mortality is low, in our experience, central pancreatectomy is associated with a high complication rate. The most common complication is pancreatic leak. Caution is necessary when using central pancreatectomy in the treatment of pancreatic neck lesions. Surgeon experience is of utmost importance in this decision-making process as well as the technical aspects of central pancreatectomy. The precise role of central pancreatectomy in the management of benign or low-malignant potential lesions of the neck of the pancreas remains in evolution.

Islet Cell Tumors of the Pancreas.

Islet cell tumors of the pancreas, also known as pancreatic neuroendocrine tumors, constitute less than 5% of pancreatic tumors, and 7% of all neuroendocrine tumors. Most are non-functional, and patients often present with metastatic disease. Functional tumors present with distinct clinical syndromes. Accurate staging is critical as surgery is both the cornerstone of treatment, and the only hope for cure. Medical management involves treating the manifestations of hormonal excess, and using somatastatin analogues when appropriate. Systemic chemotherapy, targeted molecular therapy, and peptide receptor radiotherapy may be used for refractory disease in lieu of or as an adjunct to surgery.

Nuclear medicine in the detection and management of pancreatic islet-cell tumours.

Over the last decade somatostatin receptor scintigraphy using various derivatives of long-acting somatostatin analogues has gained its place in the management of pancreatic islet-cell tumours. Scintigraphy is based on the high-affinity binding of such somatostatin analogues to receptors over-expressed by these tumour types. Following the introduction of (111)In-DTPA-D-Phe(1)-octreotide, clinical studies with radiolabelled DOTA-Tyr(3)-octreotide and DOTA-Tyr(3)-octreotate derivatives have shown considerable improvement of imaging results with increased tumour uptake. One of the newer developments, (68)Ga-labelled DOTA-Tyr(3)-octreotide, has shown promising results in patients with pancreatic islet-cell tumours, based on the high-affinity binding to the somatostatin receptor subtype 2 in combination with positron emission tomography (PET) technology. Other peptides--such as ligands for the gastrin/CCK2 receptors or vasoactive intestinal peptide (VIP)--have also been studied for imaging pancreatic cell tumours. Whereas small-sized gastrinoma, somatostatinoma, glucagonoma, carcinoid and VIPoma are frequently detected by somatostatin receptor scintigraphy, insulinoma may escape detection due to reduced receptor expression. Following peptide receptor scintigraphy, a change in patient management is reported in up to 30% of patients. When labelled with (90)Y or (177)Lu, some somatostatin analogues have been applied to patients in advanced stages of the disease. Despite positive response data in 50% of patients, long-term results and survival rates are lacking.

Quantitative tissue blood flow evaluation of pancreatic tumor: comparison between xenon CT technique and perfusion CT technique based on deconvolution analysis.

PURPOSE: There has been one report that tissue blood flow (TBF) quantification with xenon CT was effective in predicting the therapeutic response to an anticancer drug in pancreatic cancer. The purpose of this study was to evaluate the correlation between the TBF of pancreatic tumors calculated with xenon CT and those with perfusion CT, in order to evaluate whether perfusion CT could replace xenon CT. MATERIALS AND METHODS: Nine patients with pathologically proved pancreatic tumors who underwent both xenon CT and perfusion CT were included. RESULTS: Quantitative TBF of pancreatic tumors measured by perfusion CT ranged from 22.1 to 196.2 ml/min/100 g (mean+/-SD, 52.6+/-54.8 ml/min/100 g). In contrast, those obtained by xenon CT ranged from 10.3 to 173.6 ml/min/100 g (mean+/-SD, 47.4+/-49.4 ml/min/100 g). There was a good linear correlation between xenon CT and perfusion CT (y=0.8537x+2.48, R2=0.895: p<0.05). CONCLUSION: The TBF of pancreatic tumors measured by xenon CT and perfusion CT techniques showed a close linear correlation. We can expect that perfusion CT based on the deconvolution algorithm may replace xenon CT to predict the effect of pancreatic tumor treatment with anticancer drugs.

64Cu-TETA-octreotide as a PET imaging agent for patients with neuroendocrine tumors.

UNLABELLED: 64Cu (half-life, 12.7 h; beta+, 0.653 MeV [17.4%]; beta-, 0.579 MeV [39%]) has shown potential as a radioisotope for PET imaging and radiotherapy. (111)In-diethylenetriaminepentaacetic acid (DTPA)-D-Phe1-octreotide (OC) was developed for imaging somatostatin-receptor-positive tumors using conventional scintigraphy. With the advantages of PET over conventional scintigraphy, an agent for PET imaging of these tumors is desirable. Here, we show that 64Cu-TETA-OC (where TETA is 1,4,8,11-tetraazacyclotetradecane-N,N',N'',N'''-tetraacetic acid) and PET can be used to detect somatostatin-receptor-positive tumors in humans. METHODS: Eight patients with a history of neuroendocrine tumors (five patients with carcinoid tumors and three patients with islet cell tumors) were imaged by conventional scintigraphy with (111)In-DTPA-OC (204-233 MBq [5.5-6.3 mCi]) and by PET imaging with 64Cu-TETA-OC (111 MBq [3 mCi]). Blood and urine samples were collected for pharmacokinetic analysis. PET images were collected at times ranging from 0 to 36 h after injection, and the absorbed doses to normal organs were determined. RESULTS: In six of the eight patients, cancerous lesions were visible by both (111)In-DTPA-OC SPECT and 64Cu-TETA-OC PET. In one patient, (111)In-DTPA-OC showed mild uptake in a lung lesion that was not detected by 64Cu-TETA-OC PET. In one patient, no tumors were detected by either agent; however, pathologic follow-up indicated that the patient had no tumors. In two patients whose tumors were visualized with (111)In-DTPA-OC and 64Cu-TETA-OC, 64Cu-TETA-OC and PET showed more lesions than (111)In-DTPA-OC. Pharmacokinetic studies showed that 64Cu-TETA-OC was rapidly cleared from the blood and that 59.2% +/- 17.6% of the injected dose was excreted in the urine. Absorbed dose measurements indicated that the bladder wall was the dose-limiting organ. CONCLUSION: The high rate of lesion detection, sensitivity, and favorable dosimetry and pharmacokinetics of 64Cu-TETA-OC indicate that it is a promising radiopharmaceutical for PET imaging of patients with neuroendocrine tumors.

The asymptomatic pancreatic islet cell tumor: a novel presentation.

Pancreatic islet cell tumors that secrete one or several polypeptide hormones have been suspected and diagnosed secondary to their systemic manifestations. This case report details the diagnosis and treatment of an 62-year-old man with a large pancreatic islet cell tumor without symptoms in whom the mass was found as a direct result of blunt trauma to the abdomen. The tumor contained high concentrations of both vasoactive intestinal polypeptide (VIP) and somatostatin. A discussion of VIP-containing tumors is included.

Early experience with laparoscopic resections of islet cell tumors.

BACKGROUND: Diagnostic laparoscopy and laparoscopic ultrasonography have been applied recently for diagnosis and localization of islet-cell tumors. A further step was taken by performing resection of these tumors with laparoscopic techniques. METHODS AND RESULTS: We studied a retrospective series of 12 patients operated on with laparoscopic techniques since January 1992. The seven female and five male patients had a mean age of 43 years. The mean tumor size was 3 cm. Thirty-six percent of the tumor site could not be identified before operation. Eight patients underwent planned laparoscopic distal pancreatectomy (five insulinomas, two gastrinomas, and one unknown origin), and four underwent planned laparoscopic enucleation (one insulinoma and three unknown origin). Of the eight distal procedures, three had conversions (one inability to localize the tumor and two metastatic gastrinomas). Average operating time was 4.5 hours, with an average hospital stay of 5 days. Of the four explorations for possible enucleation, one was performed and one was converted to a Whipple procedure for nesidioblastoma of the head of the pancreas. The other two had negative explorations. The successful enucleation of an insulinoma of the anterior body of the pancreas was performed in 3 hours, and the hospital stay was 4 days. No recurrence was seen in the enucleated or distal pancreatectomy group in follow-up (15 to 38 months). CONCLUSIONS: Laparoscopic enucleation or resection of benign islet tumors results in a shorter hospital recovery and is a good alternative to open surgery.

Prospective study of provocative angiograms to localize functional islet cell tumors of the pancreas.

BACKGROUND: Controversy exists concerning the use of preoperative imaging studies in patients with islet cell tumors. Since 1993 we have evaluated the use of provocative angiography in patients with insulinoma or Zollinger-Ellison syndrome (ZES). METHODS: Twelve patients with a working diagnosis of insulinoma (n = 4) or ZES (n = 8) were studied. Of the eight patients with ZES, four were known to have multiple endocrine neoplasia type 1. All patients underwent conventional imaging studies followed by provocative angiography. Angiograms were graded based on the ability to detect tumor and regionalize it within the pancreas. RESULTS: Of the three patients with a working diagnosis of ZES but equivocal results of biochemical studies, none had arteriographic imaging of an islet cell tumor or a positive provocative study result (true negative result). Of the nine patients with documented islet cell tumor, seven (78%) underwent arteriographic imaging of the tumor and eight (89%) had correct regional localization by provocative angiography. Sensitivity and specificity for imaging were 78% and 100%, respectively, and for regional localization 89% and 100%, respectively. CONCLUSIONS: Provocative angiography is the localization study of choice for both gastrinoma and insulinoma. Having few false-negative results, it can be used to corroborate the diagnosis and, having few false-positive results, it detects tumor and biochemically confirms localization in nearly every patient.

Evaluation of somatostatin-receptor scintigraphy for detecting neuroendocrine tumors.

BACKGROUND: Somatostatin-receptor scintigraphy (SRS) has gained attention as an imaging modality for neuroendocrine tumors (NETs). The purpose of this study was to present one of the first American series evaluating the ability of SRS to detect local and distant disease caused by NETs. METHODS: Medical records were reviewed from 35 patients who underwent a total of 38 studies using 111In-pentetreotide between 1993 and 1995. Twenty-two patients had islet cell tumors, seven had carcinoid tumors, and six had other NETs. RESULTS: The overall sensitivity of SRS was 74% for detecting local disease (primary tumor +/- regional lymph node metastases) in all NETs, excluding insulinoma, 75% in gastrinoma, 0% in insulinoma, 78% in other islet cell tumors, and 50% in carcinoids. For detecting distant disease, the overall sensitivity of SRS was 67% for all NETs, excluding insulinoma, 100% for gastrinoma, 50% for other islet cell tumors, and 80% for carcinoids. Specificity and positive predictive value were 100% for all tumors. Negative predictive value ranged from 33% to 100%. CONCLUSIONS: A positive SRS study strongly predicts the presence of tumor (100% positive predictive value in our study). However, unlike the European reports of very high sensitivity (80% to 88%), we found that SRS had a lower sensitivity (67% for all NETs excluding insulinoma and 71% for noninsulinoma gastroenteropancreatic NETs). Thus negative SRS in patients with NETs must be viewed cautiously, because the false-negative rate is high, and this limits the use of this method in the most difficult patients.

Computed tomography and nuclear magnetic resonance imaging of pancreatic islet cell tumors.

Eleven patients with pancreatic islet cell tumors smaller than 2.5 cm were examined by use of computed tomography (CT) and new scanning protocol. Seven of 11 tumors were localized and CT accurately assessed multiple lesions, retroperitoneal invasion, or liver metastases when present. CT is now the initial imaging procedure of choice for diagnosis and staging of islet cell tumors. Nuclear magnetic resonance can distinguish islet cell tumors from normal retroperitoneal structures and appears to be a promising new pancreatic imaging modality.

The diagnosis and definition of hepatic malignancies by use of arterial enhanced computerized tomographic scanning.

Axial computerized tomography is a useful tool in the evaluation of either primary or metastatic hepatic neoplasms. An adjunct to this technique is visceral arterial enhanced computerized tomography (AECT). To determine the effectiveness of this modality, bolus intravenous enhanced computerized tomography scans and AECT were compared and correlated to operative findings. Fifty-four consecutive patients were evaluated by AECT and bolus intravenous enhanced computerized tomography over a 30-month period (May 1986 to August 1989) for suspected primary or metastatic hepatic malignancies. Forty-four patients (81%) had hepatic lesions. Fifty-two percent (23 of 44 patients) of the metastatic tumors were from colonic or rectal primary lesions, and 20% were hepatocellular primary lesions. The remainder of the lesions were metastases from a variety of primary lesions. When studies were compared, 34% of the patients (15 of 44 patients) differed in either the location or total number of lesions noted. The lesions of three of the 15 patients (20%) were determined unresectable on the basis of AECT. Of the remaining patients, planned resections were revised in seven patients to either lesser or greater procedures. The number of lesions found at laparotomy equaled the number found by AECT in all but two cases. AECT caused no complications. AECT improved our ability to identify and localize primary and metastatic lesions of the liver. This technique offers the advantage of preoperative definition of the hepatic arterial and portal venous anatomy.

Surgical experience with pancreatic islet-cell tumors.

OBJECTIVE: To review the surgical management of pancreatic islet-cell tumors, with attention to preoperative localization, surgical therapy, and postoperative survival. DESIGN: Consecutive case series of patients treated surgically for pancreatic islet-cell tumor. SETTING: The Johns Hopkins Hospital, a large teaching hospital in Baltimore, Md, serving both as a primary and tertiary care center. PATIENTS: Thirty-seven patients with pancreatic islet-cell tumors treated surgically between 1979 and 1990. MAIN OUTCOME MEASURES: Success of preoperative localization studies, types of operations performed, and postoperative survival. RESULTS: Preoperative computed tomography correctly localized the tumor in 20 of 34 patients (59%); angiography in 21 of 28 patients (75%), and the combination of computed tomography and angiography in 23 of 28 patients (82%). Benign islet-cell tumors were found in 19 patients, and malignant tumors in 18 patients. Twenty-four patients (65%) had functional tumors. The proportion of patients with nonfunctioning tumors increased from 0% before 1984, to 43% from 1985 to 1990. Surgical therapy was curative in 27 patients and palliative in 10. The most commonly performed operative procedures were tumor enucleation (11 patients [30%]), distal pancreatectomy (10 patients [27%]). There was no operative mortality. The actuarial survival at 40 months was 100% in patients with benign tumors and significantly lower (66%) in patients with malignant tumors. CONCLUSIONS: This experience from a single institution underscores the role of preoperative localization studies and appropriate surgical management of these rare tumors.

Pancreatic cystic endocrine neoplasms.

A rare case of cystic pancreatic endocrine tumor is presented, and the literature is reviewed. The patient was initially misdiagnosed as having a pancreatic pseudocyst, and that condition was managed accordingly. Persistence of the cystic lesion and reoperation led to the correct diagnosis and management. The neoplasm stained positive for glucagon and pancreatic polypeptide, but there were no clinical abnormalities that suggested hyperfunction. All cystic lesions of the pancreas should undergo biopsy at operation, to avoid an erroneous diagnosis of benign pseudocyst. Neoplastic lesions should be resected, not internally drained.