[Endocrine tumors of the duodenum and pancreas: "prerequisites", imaging, and intraoperative detection]

Radioguided Surgery for Gastrinoma: A Case Report

Aims and Background

Gastrinomas are the most common neuroendocrine tumors of the duodenopancreatic region. Surgical resection is the primary type of radical treatment.

Methods and Study Design

At the Institute of General, Gastrointestinal and Breast Surgery we treated a patient with a duodenal gastrinoma that was diagnosed and localized by means of selective celiacmesenteric angiography and labeled octreotide scintigraphy. Surgery was performed using a radioguided technique; in this way we easily detected the small tumor and discovered another tracer-uptaking lesion that turned out to be a metastatic lymph node.

Results

Surgical resection is the ideal treatment for sporadic gastrinoma: it improves quality of life, prolongs survival, and reduces the incidence of metastases, with a modest percentage of complications and practically zero mortality. Meanwhile, medical treatment is being revaluated, particulary in the case of metastatic disease or polyendocrine MEN1 syndrome. A fundamental aspect in the management of gastrinomas is tumor localization. Endoscopic ultrasonography and labeled octreotide scintigraphy (Octreoscan) proved to be more effective than the usual imaging modalities. Intraoperative ultrasonography, gastroscopy for duodenal transillumination and repeated measurement of blood gastrin levels should be performed intraoperatively in the surgical treatment of gastrinomas.

Conclusions

The clinical application of radioguided surgery for tracer-uptaking endocrine tumors is still controversial. In our case the decision to use this method was influenced by the fear that the patient's obesity and the effects of previous surgery could hamper the identification of the small tumor.

[Multiple endocrine neoplasias. Recent advances in clinical and genetic diagnosis]

PURPOSE

Multiple endocrine neoplasias (MEN) are autosomal dominant inherited syndromes characterized by the association of different glandular lesions in several members of the same kindred. The main clinical features of MEN 1 include primary hyperparathyroidism, pancreatic islet cell tumors and pituitary adenomas; less common features are adrenal adenomas, thymic and bronchial carcinoid tumors, lipomas and various cutaneous lesions. The MEN 2 syndromes (MEN 2A, MEN 2B and familial medullary thyroid carcinomas) are characterized by high penetrance of medullary thyroid carcinoma and differ in their variable expression of pheochromocytoma, hyperparathyroidism and other clinical features.

CURRENT KNOWLEDGE AND KEY POINTS

MEN 1 tumor suppressor gene encodes a nuclear protein, menin, which interacts with different regulation transcription factors. The MEN 2 syndromes are caused by germ-line mutations of the RET proto-oncogene, which encodes a transmembrane tyrosine kinase. Genetic testing for mutations in these 2 genes allows identification of individuals predisposed to the disease, early diagnosis, and clinical and therapeutic management.

FUTURE PROSPECTS AND PROJECTS

Fundamental approach will allow a best comprehension of physiopathogenic mechanisms of these disorders and the improvement of therapeutic management.

[Is preoperative localization of insulinomas necessary?]

STUDY AIM

To appreciate the impact of preoperative localization in surgical treatment of insulinomas.

PATIENTS AND METHOD

From 1986 to 2001, 29 patients were surgically treated for suspected insulinoma. Preoperative imaging assessment was performed in 26 patients: ultrasonography (n = 21), computed tomography (n = 23), endoscopic ultrasonography (n = 13), intraoperative ultrasonography (n = 22) (2 of them under laparoscopic approach).

RESULTS

The sensibility of the localization procedures was as follows: ultrasonography = 9.6%, computed tomography = 39%, endoscopic ultrasonography = 92.3%, surgical exploration 79.3%, intraoperative ultrasonography 86.3%. The sensibility of intraoperative palpation associated which intraoperative ultrasonography was 100%. Surgical procedures included: 11 enucleations, 10 segmental resections of the tail, 1 left pancreatectomy, 3 median pancreatectomies, 4 subtotal pancreatectomies. There was no postoperative mortality and postoperative morbidity rate was 17%, including 4 pancreatic leakages. Histological examination found solitary tumor in 22 patients (1 of them was a malignant tumor), multiple tumors (MEN 1) in 4 patients and factitious hypoglycemia in 3 patients. All the insulinomas were resected.

CONCLUSION

Intraoperative evaluation of the pancreas with intraoperative ultrasonography was associated which a right localization in 100% of insulinomas. The place for preoperative imaging seems to be limited. A laparoscopic approach in sporadic insulinomas could modify this attitude.