Successful Preoperative Localization Research Articles

Multiple sewing needles ingestion: a case report and review of the literatures

Sharp foreign body ingestion and management pose a great challenge to the surgeon. Majority of ingested foreign bodies pass through the gastrointestinal tract spontaneously. Organ perforations and possible migration should be kept in mind in patients with abdominal pain when the progress of the foreign body through the gastrointestinal tract cannot be ascertained by radiography. A 26-year-old male psychiatric patient presented with epigastric pain following ingestion of 18 sewing needles. His abdominal radiograph showed multiple metallic foreign bodies in the abdominal cavity consistent with the shape of sewing needles. He passed some needles spontaneously while the others which were retained were removed via a laparotomy after a successful pre-operative localization. Post-operative period was uneventful. A deliberate ingestion of foreign bodies should be kept in mind in patients with psychiatric disorders and mental retardation when they present with abdominal pain to the emergency department. An initial wait and see line of management may be instituted with the hope of spontaneous passage which can be monitored via radiological means. However, if the objects fail to pass naturally, surgery is indicated. Sharp foreign bodies which fail to pass spontaneously should be surgically removed after a proper localization since they could cause life threatening complications.

Correlation between preoperative calcium and parathormone levels with parathyroid gland volume.

Objective. Hyperparathyroidism is a prevalent disease with parathyroid adenomas being the most common cause. Surgical excision remains the standard treatment for parathyroid adenoma. Successful preoperative localization of the parathyroid adenoma could facilitate the decision regarding the extent of surgical exploration. The aim of the current study was to assess the correlation between the preoperative values of parathyroid hormone and ionized calcium with the adenoma weight and volume in patient with primary hyperparathyroidism caused by single-gland adenoma. Patients and Methods. We did this retrospective review for all patients who were diagnosed with primary hyperparathyroidism due to a solitary parathyroid adenoma in our general surgery department over 4 years. SPSS software was used to get the correlation coefficient between the peak preoperative levels of calcium and parathyroid hormone with the parathyroid adenoma weight and volume. Results. Ninety-nine patients were included into the study. The average age at surgery was 62.65±12.00 years. The correlation coefficient between the adenoma volume and weight with the preoperative ionized calcium level was weakly positive (r=0.329, p<0.01) and (r=0.281, p=0.019), respectively, while the correlation with the preoperative parathyroid hormone level was stronger (r=0.708, p<0.01) and (r=0.650, p<0.01), respectively. Conclusions. The strong positive relationship between the preoperative parathyroid hormone and calcium levels with the parathyroid adenoma size and weight can help the surgeon to predict the volume of the involved gland and avoid an unnecessary dissection.

Utility of Multimodality Approach Including Systemic FGF23 Venous Sampling in Localizing Phosphaturic Mesenchymal Tumors.

Tumor-induced osteomalacia (TIO) is one of the most common forms of acquired fibroblast growth factor 23 (FGF23)-related hypophosphatemia and is usually caused by phosphaturic mesenchymal tumors (PMTs). Although the complete resection of PMTs can cure TIO, preoperative localization of tumors by standard imaging modalities is often challenging. In addition to 18F-fluoro-2-deoxy-D-glucose positron emission tomography-computed tomography (FDG-PET) and 111In-pentetreotide scintigraphy (SRS), systemic FGF23 venous sampling (FGF23VS) has been used to help localize PMTs in specialized institutions. This study aimed to evaluate the diagnostic performance of each imaging test and their combinations in localizing PMTs. In an observational retrospective study of patients with adult-onset FGF23-related osteomalacia who underwent all 3 imaging studies (FDG-PET, SRS, and FGF23VS), the rate of successful preoperative localization of the tumors was evaluated only in the patients with pathological diagnoses of PMTs, considering the possibility that pathogenesis of patients without identified tumors might be due to other causes such as late-onset hereditary FGF23-related hypophosphatemia. A total of 30 Japanese patients with TIO (median age, 60 years [range, 28-87 years]; 10 women [33.3%]) were included in the study. The success rate of preoperative localization for each test and combinations of 2 or 3 tests among 18 patients with PMTs was as follows: 72% (FDG-PET), 72% (SRS), 94% (FGF23VS), 89% (FDG-PET, SRS), 100% (FDG-PET, FGF23VS), 94% (SRS, FGF23VS), and 100% (FDG-PET, SRS, and FGF23VS). We observed the highest localization rate of PMTs in patients with identified PMTs with the combination of FDG-PET and FGF23VS.

Highly bright aggregation-induced emission nanodots for precise photoacoustic/NIR-II fluorescence imaging-guided resection of neuroendocrine neoplasms and sentinel lymph nodes

Owing to the complementary high spatial resolution and signal-to-noise ratio, the dual-modality imaging technique of photoacoustic imaging (PAI)/the second near-infrared window fluorescence imaging (NIR-II FI) holds great promise for the detection of tumor tissues and sentinel lymph nodes (SLNs). Herein, by developing two aggregation-induced emission luminogens (AIEgens) (C-NTBD and O-NTBD) with benzodithiadiazole as the electron acceptor, PAI/NIR-II FI was applied to the diagnosis and treatment of neuroendocrine neoplasms (NENs) and their SLNs for the first time. Both AIEgens exhibited good PAI properties as well as intense NIR-II fluorescence emission. Among them, C-NTBD nanoparticles (NPs) have better PAI and NIR-II FI performance with maximum absorption at 732 nm and emission peak at 1042 nm. In NENs-bearing nude mice model, after successful preoperative localization of NENs by PAI, NIR-II FI was then used to detect SLNs. Under the NIR-II FI guidance of C-NTBD NPs, an SLN with a diameter of 1 mm located in the chest wall and far away from the primary tumor site was even detected and precisely removed. This dual-modality imaging technology could improve the detection of NENs and the accuracy of intraoperative SLNs dissection, improve patient prognosis, and provide a new strategy for the precise treatment of NENs.

Minimally invasive video-assisted parathyroidectomy (MIVAP) without intraoperative PTH determination.

Minimally invasive video-assisted parathyroidectomy (MIVAP) has become a standard approach to primary hyperparathyroidism (pHPT) since described. Although intraoperative parathyroid hormone assay (IOPTH) has been generalized as a complementary technique to MIVAP, its actual impact on the surgical success of this technique is not without controversy. The aim of this study was to describe our results in the management of pHPT with successful preoperative localization, by MIVAP technique, without IOPTH determination, confirming in a larger series our preliminary results. A retrospective descriptive study was conducted in pHPT patients treated by MIVAP with no IOPTH determination in a tertiary hospital between 2007 and 2019. A total of 167 patients were included in the study. Biochemical cure was achieved in 96.4%, and 94.1% did not present any surgical complication. The mean duration of surgery was 61min, and the mean length of hospital stay was 1.8days CONCLUSIONS: In case of positive preoperative localization studies, MIVAP is a safe and effective technique for the surgical treatment of pHPT due to a parathyroid adenoma, regardless of IOPTH determination, with a success rate > 95% and a low complication rate.

Clinical Characterization of Post-parathyroidectomy Patients with Primary Hyperparathyroidism and the Concordance of Preoperative Localization Imaging with Histopathology at a Tertiary Hospital in Manila, Philippines

BackgroundPhilippine studies on primary hyperparathyroidism (PHPT) and preoperative localization are scarce, making improvements on detection and recognition particularly difficult.ObjectiveDescribe the clinical profile of post-parathyroidectomy PHPT patients at The Medical City (TMC) and assess localization rates and concordance of neck ultrasound (UTZ) and 99mTc-sestamibi scan (MIBI) with surgical histopathologic findings.MethodologyRetrospective chart review of PHPT Filipino patients who underwent parathyroidectomy at The Medical City from January 2004 to August 2018. Clinical profile and presentations were described and compared with international data. Imaging results were compared with surgical histopathology findings and the level of agreement was determined.ResultsThirty-five patients were analyzed with female predominance (63%) and an average age of 53 years. Our population had more overt manifestations including skeletal abnormalities (51%), renal calculi (49%) and musculoskeletal symptoms (43%) prior to surgery compared to western countries, where symptoms were noted in less than 20%. MIBI had higher rates of detection than UTZ (80% versus 58%) but had similar localization rates (96.4% versus 94%). When performed together, given a positive result from either test, a much higher yield (93.8%) was observed. The level of agreement between MIBI and surgery was 72.5% (κ=0.54) while UTZ and surgery was 54.1% (κ=0.38).ConclusionOur Filipino subjects had predominantly overt symptomatic hyperparathyroidism upon diagnosis prior to surgery as opposed to more asymptomatic surgical patients in western countries. Combining UTZ and MIBI is a more successful preoperative localization approach in our setting than performing either imaging alone, especially in patients with nodular goiter.

Importance of localization of insulinomas: a systematic analysis.

Procedures suitable for preoperative localization of insulinomas are widely used but it is unclear whether they determine surgical success. We wanted to clarify whether preoperative localization or intraoperative ultrasound determines the success of surgically identifying and removing insulinomas. We performed a systematic literature search (PubMed) yielding 100 publications with patient-level data on preoperative localization procedures, intraoperative ultrasound, success of surgical identification and removal or single, benign insulinomas (published until 31 December 2016). The consequences of successful preoperative localization and intraoperative ultrasound for surgical identification and removal of an insulinoma could be analyzed for 863 and 529 patients with single benign insulinomas, respectively. Sensitivities of commonly employed methods to localize biochemically proven insulinomas were calculated for single benign (1,153 patients), multiple benign, and malignant insulinomas, also in relation to diameter and intra-pancreatic location. The success of surgery (identification and removal of single benign insulinomas) in patients with a biochemically proven insulinoma was high (approximately 98%) even in the absence of preoperative localization. However, successful preoperative localization or intraoperative ultrasonography slightly, but significantly, increased the probability of surgically identifying/removing single benign insulinomas (by 1.4% and 2.0%, P=0.012 and 0.0032, respectively). Diagnostic sensitivities of localization procedures varied widely, with GLP-1 receptor scintigraphy achieving the highest sensitivity despite its non-invasive nature. The probability of surgically identifying and removing a single, benign insulinoma is high even in the absence of successful preoperative localization or intraoperative ultrasound. However, both approaches slightly, but significantly, improve the outcome to near 100%.

Primary lymph node gastrinoma: A single institution experience

Gastrinomas are rare neuroendocrine tumors that ectopically secrete gastrin and classically originate within the duodenum or pancreas. The presence of primary lymph node gastrinoma is controversial. We report on a single institution's experience with gastrinoma, with focus on primary lymph node tumors. Patients who underwent operative resection of gastrinoma between 1992 and 2016 at a single institution were identified. A diagnosis of primary lymph node gastrinoma was defined as tumor confined to one or more resected peripancreatic lymph nodes, negative localization for any extra-nodal disease and normal gastrin postresection. In the study, 39 consecutive patients underwent operative resection of gastrinoma. Mean age was 53years and 49% were male. 93% of patients had successful preoperative localization. Furthermore, 19 patients (49%) underwent enucleation of their tumor and 14 (35.9%) a pancreatic resection. Overall 5- and 10-year survival for all patients was 80.8% and 60.7%, respectively. Primary lymph node gastrinoma was identified in 11 cases (28.2%). The presentation of primary lymph node and non-primary lymph node patients were similar. There was no significant difference in operation type, tumor size, or overall survival. At median follow-up of 59months, patients with primarylymph node gastrinoma were less likely to have persistent or recurrent disease (9.1% vs 42.9%,P=.04). This series supports the existence of primary lymph node gastrinomas, and indicates that as many as 1 in 4 patients with gastrinoma have this form of the disease. This entity should be considered when an isolated pathologic lymph node is identified, although thorough exploration is still recommended to exclude other occult disease.

Use of radiotracer labeling of pulmonary nodules to facilitate excisional biopsy and metastasectomy in children with solid tumors

PurposeExcision of suspected pulmonary metastases in children is challenging in the setting of multiple nodules or nodules that are small, deep, or soft. This study describes preoperative technetium macro-aggregated albumin (Tc 99m MAA) localization of pulmonary lesions to aid in intraoperative identification and resection. MethodsPatients with past or present pediatric solid tumors who underwent resection of pulmonary nodules following CT-guided Tc 99m MAA labeling were identified. The primary outcomes were successful preoperative localization and subsequent resection. ResultsMetastasectomy following Tc 99m MAA localization was performed 15 times in 11 patients from 2014 to 2016. Mean age was 13years; the most common diagnosis was osteosarcoma (33%). Tc 99m MAA labeling was attempted in 24 nodules with mean nodule diameter 6±5mm and mean depth from the pleural surface of 12±17mm; localization was successful in 23 nodules (96%). Subsequent resection was performed by thoracotomy in 12 cases and thoracoscopy in 3. All labeled nodules were identified intraoperatively; two were not resected and 17 of the 21 nodules resected demonstrated metastatic disease on pathology. ConclusionTc 99m MAA labeling of pulmonary nodules in children is effective in facilitating resection of sub-centimeter intraparenchymal metastases identified on preoperative imaging. Furthermore, this technique allows for thoracoscopic metastasectomy in select patients. Type of study/level of evidenceCase Series/Level IV.

Computed Tomography and Magnetic Resonance Imaging of the Thyroid and Parathyroid Glands.

Computed tomography (CT) and magnetic resonance imaging (MRI) are advanced imaging modalities that are not typically utilized as part of the initial evaluation of thyroid and parathyroid pathology. However, both modalities have applications in complex cases, particularly in the reoperative setting and in operative planning for initial or recurrent carcinomas. As part of a multimodal approach, CT and MRI can increase the successful preoperative localization of abnormal parathyroid glands. Newer imaging modalities, such as PET-CT and SPECT-CT in thyroid imaging, and 4D-CT in parathyroid imaging, can provide information on the anatomy as well as the function of pathologic tissues. Both modalities provide excellent assessment of the extent of disease, local invasion and distant metastases. Drawbacks include cost and availability, and these should be weighed against benefits in the context of the management of thyroid and parathyroid disease.

Minimally Invasive Resection for Mediastinal Ectopic Parathyroid Glands

We reviewed our experience with ectopic mediastinal parathyroidectomy. Between March 1980 and September 2010,mediastinal parathyroidectomy was performed in33 patients with hypercalcemia secondary to hyperparathyroidism. Primary hyperparathyroidism was the main diagnosis in 32 patients (97%). Technetium-sestamibi scan was used in 23 (70%) for preoperative localization. Minimally invasive resections were performed in 18 patients (55%), and 15 (45%) underwent open surgery. The most common minimally invasive surgery approach was video-assisted thoracoscopy in 9 patients (27%); the most common open approach was median sternotomy in 11 (33%). Intraoperative parathyroid hormone monitoring was used in 22 patients (67%). The ectopic glands were intrathymic in 15 patients (45%), in the aortopulmonary window in 7 (21%), and in other intrathoracic locations in the remaining 11 (33%). Parathyroid adenomas were identified in 21 patients (64%); parathyroid hyperplasia and carcinoma were identified in 9 (27%) and 3 (9%), respectively. No early mortality occurred in either group. Reoperation was required in 1 patient in the minimally invasive surgery group because of hemothorax. Morbidity occurred in 8 patients (24%), the most common of which was hypocalcemia in 4 (12%). The mean length of stay was significantly shorter in the minimally invasive surgery group (2 versus 6 days; p < 0.001) but mortality and morbidity were not statistically different between the two groups (p= 0.05). Mean follow-up was 3 ± 3.7 years. Minimally invasive mediastinal parathyroidectomy has similar outcomes to open surgery, with significantly shorter length of hospital stay.

Accurate Preoperative Localization of Parathyroid Adenomas With C-11 Methionine PET/CT

Focused unilateral or minimally invasive parathyroidectomy for primary hyperparathyroidism (pHPT) depends on the successful preoperative localization of parathyroid adenomas. The aim of this prospective study was to determine the accuracy of C-11 methionine positron emission tomography/computed tomography (Met-PET/CT), a novel localization procedure for hyperfunctional parathyroid tissue. Preoperative Met-PET/CT scans of the neck and mediastinum of 102 patients undergoing parathyroidectomy for pHPT were preoperatively evaluated by a radiologist and a nuclear medicine physician and prospectively documented. The results of Met-PET/CT were compared with intraoperative and histopathological findings. pHPT was caused by a single-gland adenoma in 97 patients, whereas 5 patients had multiglandular disease. Met-PET/CT correctly located a single-gland adenoma in 83 of 97 (86%) patients with pHPT (sensitivity 91%). The positive predictive value of Met-PET/CT in localizing a single-gland adenoma was 93%. Of the 5 patients with multiglandular disease, Met-PET/CT identified 2 hyperfunctioning parathyroid glands in 1 patient, 1 gland in 3 individuals, and was negative in the fifth patient (sensitivity 80%). A highly significant correlation was observed between true-positive findings and the size (mean = 1.81 ± 0.84 cm) and weight (mean = 1.50 ± 2.56 g) of parathyroid adenoma, whereas patients with false-negative findings had significantly smaller (mean = 1.09 ± 0.41 cm) and lighter (mean = 0.37 ± 0.29 g) glands (P < 0.001 and P = 0.001, respectively). This study demonstrates the high accuracy of Met-PET/CT in the preoperative localization of parathyroid adenomas in a large series of patients with pHPT.

Ectopic Parathyroid Glands and their Anatomical, Clinical and Surgical Implications

Ectopic parathyroid glands result from aberrant migration during early stages of development and lack of successful identification may lead to lack of success in parathyroid surgery. They constitute a common etiology of persistent or recurrent hyperparathyroidism, when they are missed at initial diagnosis. Their prevalence is about 2-43% in anatomical series and up to 16% and 14% in patients with primary and secondary hyperparathyroidism, respectively. Ectopic inferior parathyroids are most frequently found in the anterior mediastinum, in association with the thymus or the thyroid gland, while the most common position for ectopic superior parathyroids is the tracheoesophageal groove and retroesophageal region. Neck ultrasound and 99mTc Sestamibi scan are first-line imaging modalities, although with low sensitivity and specificity. However, their combination with modern techniques, such as single photon emission computed tomography (SPECT) alone or in combination with CT (SPECT/CT) increases their diagnostic accuracy. Fine needle-aspiration cytology of a lesion suspicious for parathyroid tissue and measurement of parathyroid hormone (PTH) in the aspired material further assist to the successful preoperative localization of ectopic glands. Common sites for surgical investigation are the upper thyroid pole and the upper vascular thyroid stalk behind the hypopharynx and cervical esophagus for the superior parathyroids, and the carotid artery bifurcation and the thymic tongue, for the inferior parathyroids. Radioguided minimally invasive parathyroidectomy after successful localization, assisted by rapid PTH measurement postoperatively, significantly improves surgical outcomes in patients with ectopic parathyroid adenomas.

Primary hyperparathyroidism – a diagnostic approach

Primary hyperparathyroidism (PHPT) is characterized by the autonomous production of parathyroid hormone (PTH), in which there is hypercalcemia or normal-high serum calcium levels, in the presence of elevated or inappropriately normal serum PTH concentrations. Diagnosis of PHPT is biochemical. Advances in imaging technology, intraoperative parathyroid hormone measurement, and surgical technique now allow parathyroidectomy to be performed using a focused approach without the absolute need of a fourgland exploration. This brief review summarizes the various diagnostic modalities available for successful preoperative localization and management of the modern day PHPT patient. Sri Lanka Journal of Diabetes, Endocrinology and Metabolism 2012; 2 : 101-105 DOI: http://dx.doi.org/10.4038/sjdem.v2i2.4780

Successful Pre-operative Localization of a Neuroendorine Tumor of the Pancreas Using EUS Guided Fine Needle Tattoo

Successful Pre-operative Localization of a Neuroendorine Tumor of the Pancreas Using EUS Guided Fine Needle Tattoo

Negative preoperative localization leads to greater resource use in the era of minimally invasive parathyroidectomy

Background Successful preoperative localization plays an important role in patient selection for focused parathyroidectomy. Methods The case records of 499 consecutive patients with presumed hyperparathyroidism who underwent neck exploration were reviewed. Positive imaging patients (n = 373) had a localizing study that clearly showed a single abnormal parathyroid gland whereas negative imaging patients (n = 44) failed to localize or had discordant imaging results. Results Positive imaging patients were more likely to have a single adenoma (93.0% vs 72.1%; P < .001), and were less likely to require a bilateral exploration (8.1% vs 70.4%; P < .001). Negative imaging patients required more frozen sections (.9 ± 1.3 vs .2 ± .7; P < .001), and longer surgical time (77.3 ± 52.5 min vs 48.4 ± 34.6 min; P < .001). The cure rate was significantly higher in the positive imaging group (96.0% vs 87.1%; P < .03), with no difference in the incidence of complications (3.2% vs 2.3%; P value was not significant). Conclusions Patients with unsuccessful or discordant preoperative localization have a higher incidence of multigland disease, lower cure rate, and consume more institutional resources than patients with successful preoperative localization.

Secular Trends in the Presentation and Management of Functioning Insulinoma at the Mayo Clinic, 1987–2007

The objective of the study was to assess changes in the presentation and diagnostic and radiological evaluation of patients with surgically confirmed insulinoma at the Mayo Clinic 1987-2007. A retrospective analysis of patients with insulinoma was conducted. Patients with prior gastric bypass were excluded. A total of 237 patients [135 women (57%)] were identified. Hypoglycemia was reported solely in the fasting state in 73%, the fasting and postprandial state in 21%, and exclusively postprandially in 6%. There was a predominance of men in the postprandial symptom group. Considering the period of study by quartile, outpatient evaluation increased from 35 to 83% and successful preoperative localization improved from 74 to 100% comparing the first to the fourth quartiles. Although the rates of localization by noninvasive techniques remained static at approximately 75%, the addition of invasive modalities has resulted in successful preoperative localization in all patients in the past 10 yr. The sensitivity and specificity of the established diagnostic criteria using insulin, C-peptide, proinsulin, beta-hydroxybutyrate, and glucose response to iv glucagon were greater than 90% and greater than 70%, respectively. Although fasting hypoglycemia is characteristic of patients with insulinoma, postprandial symptoms have been reported with increasing, albeit low, frequency. Trends in the evaluation and preoperative management include a shift to outpatient diagnostic testing, an emphasis on successful preoperative localization to avoid blind pancreatic exploration, and a validation of the diagnostic criteria for hyperinsulinemic hypoglycemia.

Negative Imaging Studies for Primary Hyperparathyroidism Are Unavoidable: Correlation of Sestamibi and High‐Resolution Ultrasound Scanning with Histological Analysis in 150 Patients

Preoperative localization studies with Tc99m-sestamibi have become an integral step in the preoperative assessment of patients with primary hyperparathyroidism (PHPT). This enables scan-directed minimally invasive parathyroidectomy (MIP) to be the preferred treatment for PHPT in many units. This study aimed to identify factors that lead to negative imaging studies in patients with PHPT. Over a 3-year period consecutive unselected patients with PHPT underwent Tc99m-sestamibi scanning and high-resolution ultrasound (US) scanning by the same radiologist. When localization studies were concordant, patients underwent MIP. Those patients with negative imaging studies underwent bilateral neck exploration. Histology slides were independently reviewed and the proportion of chief cells and oxyphil cells within each adenoma was estimated. One hundred and fifty-eight patients underwent localization studies (38 men and 120 women, aged 61.8 +/- 15.2 years). Sestamibi scans were negative in 52 (32%) and positive in 106 (68%) patients. There was a higher incidence of hyperplasia in the group of patients with negative sestamibi scans (4 out of 52 vs. 4 out of 103, P < 0.05, chi2 test). In patients with negative sestamibi scans the majority of adenomas were formed predominantly from chief cells (26 out of 36) while the majority of patients with adenomas composed predominantly of oxyphil cells had positive scans (21 out of 23) (P < 0.05, chi2 test). The weight of parathyroid adenomas was higher when sestamibi scans were positive (median: 1,180 vs. 517 mg, P < 0.05, Student's t-test). Successful preoperative localization of parathyroid adenomas using Tc99m-sestamibi scanning is influenced by the cytological predominance of individual tumors. Negative scans might therefore be unavoidable in a subgroup of patients.

Intraoperative Parathyroid Hormone Monitoring

The principles of minimally invasive parathyroidectomy include the successful preoperative localization of a solitary adenoma, a targeted operative approach that does not disturb the normal parathyroid glands, and intraoperative confirmation of excision of all hypersecreting parathyroid tissue. By providing real-time feedback to the surgical team, the rapid PTH assay allows surgeons to assess the completeness of parathyroid resection without visualizing all the parathyroid glands. Intraoperative PTH monitoring facilitates the use of local anesthesia, decreases the duration of surgery, and allows ambulatory surgery in most patients. This article reviews current recommendations and controversies surrounding the use of intraoperative PTH monitoring during parathyroidectomy.

Preoperative localization of insulinomas is not necessary

Background: Insulinomas are infrequent but are important to recognize and surgically remove. Several diagnostic tests have been used to increase the chances of operative success. The value of preoperative testing for insulinomas is the subject of this review.Study Design: All patients treated at the Cleveland Clinic for insulinoma between 1985 and 1995 were retrospectively reviewed. All patients had biochemical evidence of primary hyperinsulinemia.Results: There were 21 patients, 10 men and 11 women, with a median age of 58 years. Eighteen patients (85%) had a single insulinoma, two patients (10%) had multiple insulinomas, and one patient (5%) had nesidioblastosis. In addition, two patients (10%) had malignant insulinoma. A total of 13 patients (62%) had successful preoperative localization of their tumors, and all of these were found during exploration either by the surgeon (12 patients) or by intraoperative ultrasonography (1 patient). The remaining eight patients (38%) did not have their lesion localized by preoperative tests. In seven patients these tumors were found at operation, three by the surgeon and four by intraoperative ultrasonography. One patient failed preoperative and intraoperative localization and was later diagnosed with nesidioblastosis. Enucleation was performed in 13 patients and distal pancreatectomy in 7; the patient with nesidioblastosis had a negative laparotomy and a subsequent distal pancreatectomy. The mortality and morbidity rates were 0% and 14%, respectively. Only two patients, including the patient with nesidioblastosis, remained symptomatic after operation.Conclusions: The diagnosis of an insulinoma does not require extensive localization studies before operation. The combination of surgical exploration and intraoperative ultrasonography identified more than 90% of insulinomas. When technically feasible, enucleation is curative and can be accomplished with low morbidity.