Severe chronic diarrhoea secondary to primary lymph node gastrinoma

Abstract

The existence of primary lymph node (LN) gastrinoma is questionable and controversial. In fact, the presence of gastrinoma in such uncommon site raises the possibility of metastasis from another occult primary site. An extensive evaluation and careful follow-up is always warranted. A female aged 48 years presented with chronic abdominal pain and watery diarrhoea. Her serum gastrin and chromogranin were elevated, and an underlying gastrinoma was suspected. Further evaluation with an octreotide scan, an endoscopic ultrasound and a secretin stimulation test confirmed the diagnosis. Further evaluation for multiple endocrine neoplasia-1 syndrome was negative. She underwent a surgical enucleation near the head of the pancreas. No other lesions were found after careful exploration of the gastrinoma triangle. Histology showed a LN with a neuroendocrine tumour that tested positively with gastrin and chromogranin stains. Her symptoms resolved postoperatively, her serum gastrin normalised and a repeated octreotide scan was negative.

Keywords: Endoscopy; Gastrointestinal hormones; Pancreas and biliary tract.

Figure 1

(A) The preoperative octreotide scan showing an abnormal focus of radiopharmaceutical accumulation near the region of the pancreatic head, in addition to a pedunculating enhancing mass near or extending from the posterior aspect of the pancreatic head. (B) The postoperative octreotide scan showing no abnormal focus of uptake of the radiopharmaceutical.

Figure 2

A triple-phase CT scan of the pancreas showing pedunculating hyperenhancing lesion near or arising from the posterior aspect of pancreatic head.

Figure 3

H&E stain of the biopsy (A) shows low-grade neuroendocrine tumour and lymph node. Immunohistochemical stain for chromogranin (B) and gastrin (C, D) show diffuse cytoplasmic positivity.