Endocrinology through an endoscope: lesions in the esophagus, stomach, and duodenum in gastrinoma

[Fig. 1] shows the upper endoscopy of a 58-year-old man who was admitted for persistent gastrointestinal bleeding, which eventually required angiography with coiling of the side branches of the pancreaticoduodenal artery.

Fig. 1 Endoscopic view of a the esophagus, b the stomach, and c the duodenum, showing severe reflux esophagitis, multiple fundic gland polyps, and a single ulcer in the descending part of the duodenum.

He had been using rabeprazole (20 mg/day) for gastroesophageal reflux disease since 2007. Although a single duodenal ulcer usually requires no further testing, the severity of the bleeding and the extent of the lesions warranted further investigation. Additional tests – serum gastrin (1500 ng/L, normal < 115 ng/L), chromogranin A (1150 µg/L, normal < 94 µg/L), a positive secretin stimulation test (serum gastrin 5251 ng/L 10 minutes after an intravenous 2 U/kg bolus), and somatostatin receptor scintigraphy and endoscopic ultrasound ([Fig. 2]) – suggested a gastrinoma.

Fig. 2  Preoperative images of the peripancreatic lymph node gastrinoma as visualized by a somatostatin receptor scintigraphy and b endoscopic ultrasound.

Other possibilities were excluded by appropriate tests, including Helicobacter pylori, drug-associated causes, vasculitis, ischemia, herpes simplex, and cytomegalovirus. Computed tomography did not identify the lesion shown in [Fig. 2] or any metastases. During surgery, a palpable lesion near the pancreas was enucleated. Pathological analysis confirmed a peripancreatic lymph node gastrinoma.

This case illustrates the following points. First, fundic gland polyps are a less recognized but diagnostically useful manifestation of gastrinoma [1]. Although long-term proton-pump inhibitor therapy can also cause gastric fundic gland polyposis, this manifestation is usually not so elaborate as observed here ([Fig. 1]) [2]. Second, relying on these and other more subtle manifestations may become increasingly important with the widespread use of proton-pump inhibitors, which may mask symptoms and delay diagnosis [3], as in our case. Third, the secretin stimulation test remains essential to differentiate gastrinoma from hypergastrinemia due to proton-pump inhibitors, although a false-positive test was recently reported [4]. Finally, our case reiterates the usefulness of somatostatin receptor scintigraphy and endoscopic ultrasound in the preoperative work-up of gastrinoma [5].

Endoscopy_UCTN_Code_CCL_1AB_2AD_3AB

References

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• 2 Freeman H J. Proton pump inhibitors and an emerging epidemic of gastric fundic gland polyposis.  World J Gastroenterol. 2008;  14 1318-1320
• 3 Wong H, Yau T, Chan P et al. PPI-delayed diagnosis of gastrinoma: oncologic victim of pharmacologic success.  Pathol Oncol Res. 2010;  16 87-91
• 4 Goldman J A, Blanton W P, Hay D W et al. False-positive secretin stimulation test for gastrinoma associated with the use of proton pump inhibitor therapy.  Clin Gastroenterol Hepatol. 2009;  7 600-602
• 5 Zimmer T, Stölzel U, Bäder M et al. Endoscopic ultrasonography and somatostatin receptor scintigraphy in the preoperative localisation of insulinomas and gastrinomas.  Gut. 1996;  39 562-568