Zollinger-Ellison Syndrome in a 12-year-old Child.

The syndrome described by Zollinger and Ellison in 1955 is a rare clinical entity which is even rarer in children. This report describes a 12-year-old boy who presented with refractory peptic ulcer disease which was finally diagnosed to be due to a gastrinoma and was successfully treated.

INTRODUCTION

The overall incidence of Zollinger–Ellison syndrome is 0.1–3/million and among these patients, only 2% belong to the pediatric population.[1] Most of these tumors are located in the duodenum, but they are typically found in the well-described Passaro's gastrinoma triangle.[2] We report a case of this rare entity which requires a high index of suspicion in cases of refractory peptic ulcer disease.

CASE REPORT

A 12-year-old boy weighing 35 kg presented with a history of severe epigastric pain, vomiting, and occasional loose stools for 1 year with a weight loss of about 10 kg. Physical examination showed epigastric tenderness but no other abnormalities. Acute pancreatitis was ruled out. With a provisional diagnosis of peptic ulcer disease, H2 receptor blocking agents and proton pump inhibitors were started. However, the patient was refractory to this treatment. Upper gastrointestinal endoscopy showed severe esophagitis with gastric mucosal thickening with multiple mucosal ulcerations in duodenum. On further investigation, ultrasound of the abdomen showed a heterogeneous, hyperechoic lesion in the head of pancreas with severe degree of gastric mucosal thickening. Further confirmation done with contrast-enhanced computed tomography (CT) abdomen showed 3.8 cm × 2.8 cm well defined moderately enhancing soft tissue lesion, in Passaro's triangle arising from the head of the pancreas and anterolaterally reaching the lesser curvature of stomach [Figure 1]. Laterally and posteriorly, the lesion was abutting the left lobe and caudate lobe of liver, respectively. The gastric wall was significantly thickened. To confirm the diagnosis of a secreting tumor, fasting serum gastrin levels were sent which turned out to be high - 940 pg/ml (N = 15–113 pg/ml). Plasma chromogranin A levels were also high - 1310 ng/ml (N < 108 ng/ml) suggestive of a neuroendocrine tumor. The tumor was located in the lesser sac at the superior border of head of pancreas supplied by a branch of superior pancreaticoduodenal artery and was excised in toto. It measured about 4 cm × 4 cm × 4 cm in size [Figure 2]. There were no enlarged lymph nodes or peritoneal deposits. The postoperative course was uneventful. Histopathology confirmed the diagnosis of gastrinoma. Preoperative ultrasonography had shown gastric mucosal thickening of 2.5 cm, which reduced significantly to 4 mm postoperatively. The patient is pain-free without any medication at 2 months follow-up and is under surveillance.

Figure 1

Contrast-enhanced computed tomography abdomen showing mass with thickened gastric wall

Figure 2

Intraoperative photograph showing tumor

DISCUSSION

Gastrinomas are the second most common pancreatic neuroendocrine tumors after insulinomas.[3] In the pediatric age group, they have an infrequent prevalence.[1] The youngest reported case was just under 2 years of age.[4] The definitive diagnosis of gastrinoma requires demonstration of high levels of gastrin in fasting serum (>1000 pg/ml). Our patient had similar elevated levels, i.e., 940 pg/ml. Another important diagnostic clue was the presence of thickening of the gastric mucosa seen on simple ultrasound imaging associated with a mass. This, according to us, provides corroborative evidence that the mass is secreting gastrin. Pancreatic gastrinomas are usually large (mean 3.8 cm) unlike duodenal tumors (mean 0.93 cm)[5] as was the case with our patient but giant gastrinomas have also been reported.[67] These tumors are classically described in the Passaro's gastrinoma triangle (85%–95%), but stray cases of other locations such as lymph nodes,[8] liver, bile duct, and ovary[9] have been seen. The use of gastric mucosal thickness on ultrasound as an indicator of hypertrophy of the parietal acid-secreting cells of the stomach due to the effect of a gastrin-secreting tumor has not been reported in literature. We think that this can be a very useful modality to increase the suspicion of a possible neuroendocrine tumor. It is especially relevant in the cases of small tumors (<1 cm) which cannot be picked up on conventional imaging modalities such as CT scan and ultrasound. These tumors can be benign or malignant. In children, most recent studies report a malignancy rate of close to 30%.[1] The poor prognostic factors include liver and lymph node metastasis, large tumor size (>3 cm), short history of disease, inadequate control of gastric hypersecretion, and various histopathological and flow cytometric features among others.[5] Hence, regular follow-up and surveillance of these patients are mandatory.

CONCLUSION

Gastrinoma should be suspected in children of refractory peptic ulcer disease. Gastric mucosal thickness on ultrasound or CT scan can serve as a good corroborative diagnostic as well as follow-up modality in these patients.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.