Endocrine Abstracts

Introduction: Multiple endocrine neoplasia type 1 (MEN1) is a rare, heritable syndrome characterized by a hyperparathyroidism, pituitary adenoma and pancreatic islet cells.

Case: A 56-year-old male patient had a single parathyroid excised for primary hyperparathyroidism 10 years ago. He was further investigated due to hypoglycemia and a mass was found in the head of the pancreas on MRI. It was reported as neuroendocrine tumor and no recurrence was found in the 7-year follow-up. The patient who applied to our hospital for further examination in 2020 has been having intermittent diarrhea attacks for 3 years. In the CT examination, hemangioma in the liver, well-circumscribed tumor in the pancreatic head, and right adrenal nodule were detected. Considering a neuroendocrine tumor, Ga-68 PET/CT examination was performed. High GaTaTe uptakes were detected in the head of the pancreas and in the second part of the duodenum. In addition, nodular thickening was detected in the right adrenal gland, but GaTaTe uptake was not observed. Metanephrine and normetanephrine were examined and found to be normal. PTH: 165.1 (15–65) pg/ml Ca: 11.39 (8.6–10) mg/dl and other tests including pituitary hormone panel, insulin, c-peptide and gastrin were found to be normal. Nephrolithiasis was detected in the CT scans of the patient. There are ulcers in the small intestine on gastroscopy. No adenoma was detected in the pituitary MRI examination. Later, the patient was referred to general surgery for excision. The remaining parathyroid glands were excised. The pancreatic head tumor was found to be compatible with insulinoma, and involvement in the duodenum was found to be compatible with gastrinoma.

Conclusion: The clinical diagnosis of MEN1 is based on the formation of two or more primary MEN1-related tumors (parathyroid gland, anterior pituitary, and enteropancreatic). Our patient is a classic example of MEN1 syndrome with tumors in 2 defining endocrine organs.

Keywords: MEN1, Hyperparathyroidism, pancreatic islet tumor.