387- A 30-year-old woman presented with upper abdominal pain and recurrent epi-
sodes of vomiting for the last 2 years. She is on pantoprazole (40 mg twice
daily) with no relief in her symptoms. Upper gastrointestinal endoscopy
revealed multiple ulcerations in the stomach and duodenum. How to proceed
further?
Multiple gastrointestinal ulcerations particularly at unusual sites (beyond sec-
ond part of the duodenum) and resistance to proton pump inhibitors should
raise a suspicion of gastrinoma in this patient. The initial biochemical evalua-
tion includes estimation of fasting serum gastrin after appropriate precaution
(omission of proton pump inhibitors for at least 7 days). Serum gastrin level
>150 pg/ml and increased basal gastric acid secretion (gastric pH <2) estab-
lishes the diagnosis. Mild hypergastrinemia has also been reported due to
hypercalcemia as a result of primary hyperparathyroidism which is usually
associated with gastrinoma in MEN1 syndrome. Provocative tests may be
required in patients with mild hypergastrinemia to differentiate between antral
G-cell hyperplasia and gastrinomas.- In the above patient, the fasting serum gastrin level was 267 pg/ml and basal
gastric pH <2. CECT abdomen was normal; however, endoscopic ultrasound
revealed a 0.5 × 0.5 cm mass lesion at second part of the duodenum. What to do
next?
High fasting serum gastrin levels and very low gastric pH suggest the diagnosis
of gastrinoma. CT scan is usually normal as these are very small tumors and
endoscopic ultrasound (EUS) is more yielding. In the index patient, EUS local-
ized the lesion in second part of the duodenum. The common sites of gastrino-
mas are second part of the duodenum, antrum of the stomach, and sometimes in
the pancreas. Approximately 40 % of patients with MEN1 have gastrinomas,
and 20 % of patients with gastrinomas have MEN1 syndrome. Therefore, all
patients with gastrinomas should be evaluated for MEN1. PHPT is the most
common- presenting manifestation of MEN1 (85 %), and gastrinomas are usu-
ally associated with PHPT. Serum calcium profile and iPTH were performed in
this patient and it was suggestive of PHPT.- What are the characteristics of gastrinomas with MEN1 syndrome?
The gastrinomas associated with MEN1 syndrome are usually small (<5 mm) and
are frequently multiple. Over 80 % of gastrinomas are found within the arbitrary
triangle, known as “gastrinoma triangle” formed by confluence of cystic and com-
mon bile duct superiorly, junction of second and third portion of the duodenum
inferiorly, and junction of the neck and body of the pancreas medially. Gastrinomas
associated with MEN1 are more often present in duodenal wall than in the pan-
creas. The duodenal gastrinomas usually arise deep in the mucosa, adapt indolent
course but frequently metastasize to peripancreatic lymph node and rarely to the11 Multiple Endocrine Neoplasia