Multiple Endocrine Neoplasia Type 1: A Case Report With Review of Imaging Findings

Abstract

Background: Multiple endocrine neoplasia type 1 (MEN1) is a rare, autosomal dominant inherited syndrome caused by mutations in the MEN1 tumor suppressor gene. The diagnosis is defined clinically by the presence of 2 or more primary MEN1 tumors (parathyroid, anterior pituitary, and pancreatic islet). We describe the case of a patient who presented with classic history and imaging findings for MEN1.

Case report: A male in his early thirties with a history of hyperparathyroidism and a transsphenoidal prolactinoma resection presented years later with abdominal symptoms concerning for Zollinger-Ellison syndrome: worsening epigastric abdominal pain, nausea, vomiting, and diarrhea. Contrast-enhanced computed tomography (CT) of the abdomen revealed hyperenhancing pancreatic lesions and duodenal inflammation, suggesting pancreatic neuroendocrine tumor (gastrinoma) with secondary duodenitis. Bilateral indeterminate hypoattenuating adrenal nodules were also seen on contrast-enhanced CT, and follow-up magnetic resonance imaging confirmed benign adrenal adenomas. Furthermore, thyroid ultrasound and sestamibi scintigraphy revealed a parathyroid adenoma. With confirmatory imaging findings, history, and presenting symptoms, the patient was clinically diagnosed with MEN1 syndrome and underwent surgical and medical management.

Conclusion: This case exhibits the classic history with corresponding imaging findings of MEN1 syndrome, including pancreatic neuroendocrine tumors, parathyroid adenoma, and adrenal adenomas. High clinical suspicion for MEN1 should lead to endocrinology evaluation with appropriate laboratory workup and targeted imaging evaluation of the typical endocrine organs as described for this patient.

Keywords: Adrenal gland neoplasms; Zollinger-Ellison syndrome; gastrinoma; multiple endocrine neoplasia type 1; neuroendocrine tumors; parathyroid neoplasms; pituitary neoplasms.

Figure 1. A:. Coronal contrast-enhanced computed tomography (CT) of the abdomen demonstrates a large hyperenhancing pancreatic body mass (arrows) and duodenal wall thickening with surrounding fat stranding (arrowheads). B: Axial contrast-enhanced CT of the abdomen shows the hyperenhancing pancreatic body mass (arrows) as well as indeterminate bilateral adrenal nodules (open arrows).

Figure 2.. Endoscopic ultrasound shows the corresponding 4.2 × 2.7 × 2.8-cm heterogeneously echogenic mass at the pancreatic body that was biopsied.

Figure 3.. Axial magnetic resonance imaging with in-phase (A) and opposed-phase (B) imaging through the adrenal glands demonstrates diffuse loss of signal within the adrenal nodules on opposed-phase imaging, diagnostic of benign adenomas (arrows). A lobular pancreatic body mass is noted (arrowheads).

Figure 4.. Longitudinal ultrasound (A) through the right lobe of the thyroid gland demonstrates a hypoechoic nodule inferior to the right lobe (white arrows). Immediate (B) and delayed (C) sestamibi scans were obtained for further characterization. Focally increased uptake with a delayed washout is visible along the lower pole of the right thyroid lobe (black arrows), confirming that the nodule seen on ultrasound was a parathyroid adenoma.