Gastrinomas: gastrin-producing tumors

Resolved and unresolved controversies in the surgical management of patients with Zollinger-Ellison syndrome

OBJECTIVE

Highlight unresolved controversies in the management of Zollinger-Ellison syndrome (ZES).

SUMMARY BACKGROUND DATA

Recent studies have resolved some of the previous controversies including the surgical cure rate in patients with and without Multiple Endocrine Neoplasia-type1 (MEN1), the biological behavior of duodenal and pancreatic gastrinomas, role of imaging studies to localize tumor, and gastrectomy to manage acid output.

METHODS

Review of the literature based on computer searches in Index Medicus, Pubmed and Ovid.

RESULTS

Current controversies as identified in the literature include the role of endoscopic ultrasound (EUS), surgery in ZES patients with MEN1, pancreaticoduodenectomy (Whipple procedure), lymph node primary gastrinoma, parietal cell vagotomy, reoperation and surgery for metastatic tumor, and the use of minimally invasive surgical techniques to localize and remove gastrinoma.

CONCLUSIONS

It is hoped that future studies will focus on these issues to improve the surgical management of ZES patients.

Ectopic gastrinoma and Zollinger-Ellison syndrome

In Zollinger-Ellison syndrome (ZES), the discovery of gastrinomas in unusual locations, such as a lymph node, poses a diagnostic problem centered on whether the neoplasm is primary or metastatic. The clinical, gross, microscopic, immunocytochemical, and ultrastructural features of ectopic gastrinomas were studied in four patients with ZES, and reports of 14 similar cases were reviewed. These extragastroenteropancreatic (EGEP) gastrinomas have many of the morphologic features of gastrinomas in conventional locations. However, the centrifugal expansile growth pattern, characterized by a thick fibrous capsule, hyalinized fibrous septa, and, frequently, cystic degenerative changes in EGEP gastrinomas should alert the pathologist to the probability that these neoplasms are primary. Additional evidence for the primary nature of these EGEP gastrinomas is derived from the postoperative normalization of high serum gastrin levels and the correction of the abnormal gastrin response to secretin challenge or to calcium infusion tests. Increased awareness of the occurrence and features of these EGEP gastrinomas is crucial for both pathologists and surgeons to ensure proper evaluation and treatment of patients with ZES.

Pancreatic polypeptide (PP) immunoreactivity in human parathyroid culture media

Media from cultures of normal and abnormal human parathyroid fragments were assayed for parathyrin (PTH) and pancreatic polypeptide (PP) using sensitive radioimmunoassays. PP immunoreactivity was present in media (Day 6-7 in vitro) from cultures of 3/10 adenomas and 6/6 3 degrees hyperplastic glands (mean = 126. fmole/mg protein/day) (range = 6.-675.), and was not suppressed by 0 leads to 3 mM calcium challenge. PP was undetectable in media from cultures of one parathyroid carcinoma, one 1 degree hyperplasia, and one normal parathyroid. Medium C-terminal PTH levels were quite variable (26.-2,545,000. pg/mg protein/day). Presence of PP immunoreactivity in media from cultures of some hyperplastic parathyroids and some parathyroid adenomas suggests that PP may be released from these tissues in vitro. The significance of elevated PP levels in the MEA syndromes may be of special clinical relevance to this observation.

A case of multiple endocrine adenomatosis with primary amenorrhoea

A well documented sporadic case of multiple endocrine adenomatosis (MEA) type I, with the pituitary tumour presenting as a prolactinoma, is described in a 28-year-old female. Primary amenorrhoea, resulting from hyperprolactinaemia, was the first symptom of the polyglandular neoplasia. A gastrinoma was removed from the head of the pancreas and latent hyperparathyroidism appeared to be present. Treatment with bromocriptine was poorly tolerated; neurosurgical intervention was refused by the patient. The possibility that a serum prolactin determination may be useful in detecting pituitary involvement in MEA deserves consideration.

Experimental retained antrum. Diagnostic technics and histopathologic correlations

Retained gastric antrum was evaluated in six dogs, and diagnostic methods correlated with histopathology. Secretin and calcium infusion did not significantly alter circulating gastrin levels. 99 mTc scanning was uniformly positive and did not depend on the presence of parietal cells. The failure to consistently develop hypergastrinemia and the absence of gastrin cell hyperplasia suggest that factors other than gastrin may be implicated in the recurrent ulceration seen with retained antrum.

Cimetidine in the management of the Zollinger-Ellison syndrome

The first case of the Zollinger-Ellison syndrome treated from the outset continuously for more than a year with the histamine H2-receptor antagonist cimetidine is reported. Symptomatic response has been dramatic and sustained, marked endoscopic improvement has been observed with healing of oesophageal, gastric and stomal ulcers.