Multiple Endocrine Neoplasia Type 1 (MEN-1) is an autosomal dominant condition associated with tumours of the pancreas, parathyroid and pituitary gland [1]. Amongst pancreatic neuroendocrine tumours, 60-90% are non-functioning [2,3]. We discuss the atypical presentation of MEN-1 with a perforated viscus in the context of newly diagnosed pancreatic neuroendocrine tumours and primary hyperparathyroidism.
A 33-year-old Caucasian male presented with a duodenal perforation complicated by peritonitis and septic shock. PTH-dependent hypercalcaemia (corrected calcium 3.09mmol/L and PTH 73.1pmol/L) and ureteric calculi were incidentally identified in the context of longstanding hypercalcaemia, recurrent ureteric calculi and a multigenerational family history of primary hyperparathyroidism. Investigations identified a 21mm parathyroid lesion, multiple FDG-avid bony lesions most consistent with Brown’s tumour, a left forearm T-score -3.3 SD consistent with osteoporosis and multiple Ga-68 DOTATATE-PET avid pancreatic lesions.
He was initially treated with a left parathyroidectomy and partial thyroidectomy followed by a completion parathyroidectomy. Histopathology confirmed left superior and right parathyroid adenoma with right parathyroid hyperplastic nodules. Endoscopic Ultrasound guided biopsy confirmed the presence of Grade 1 Pancreatic Neuroendocrine Tumours. There were elevations of serum chromogranin A 1147 mcg/L (<102), glucagon 306pg/mL (<208), pancreatic polypeptide 228pmol/L (<=55) and gastrin 65pmol/L (5-55) in the context of proton pump inhibitor usage. However, he had no clinical features of a VIPoma, insulinoma or glucagonoma, and his serum gastrin levels were not grossly elevated despite his presentation with a duodenal perforation. Genetic studies confirmed a variant c.459C/G in exon 3 of the MEN1 gene consistent with MEN1 syndrome.
This case demonstrates the presentation of duodenal perforation which led to a formal diagnosis of pancreatic neuroendocrine tumours and MEN1 syndrome. The hypercalcaemia likely has exacerbated the gastrin production and resulted in the duodenal perforation. It highlights the importance of considering MEN diagnosis in young onset primary hyperparathyroidism to prevent potential neuroendocrine related complications.