Multimodal Imaging Approach to MEN-1 Syndrome-Associated Tumors

Abstract

Multiple endocrine neoplasia type 1 (MEN-1) is an autosomal dominant inherited syndrome characterized by a genetic predisposition for the development of specific hormone-secreting tumors. Effective diagnosis and management of MEN-1 require genetic testing, regular surveillance, and imaging follow-up to detect and monitor tumor growth or recurrence and to plan for surgical intervention. The aim of this narrative review is to provide an overview of the current imaging modalities and their role in the diagnosis and follow-up of patients affected by MEN-1, focusing on the detection and characterization of associated neoplasms. The knowledge of the most frequent MEN-1 associated neoplasms and their imaging features is crucial for an accurate diagnosis, management, and treatment.

Keywords: CT; MEN-1; MRI; functional imaging; pancreas; parathyroid; pituitary gland.

Figure 1

Young female MEN-1 patient, aged 19 at initial diagnosis. Ultrasound revealed a parathyroid adenoma (arrow in a,b) and MRI highlighted a pituitary macroadenoma (arrowhead in c–e) and a pancreatic NET (arrow in f).

Figure 1

Young female MEN-1 patient, aged 19 at initial diagnosis. Ultrasound revealed a parathyroid adenoma (arrow in a,b) and MRI highlighted a pituitary macroadenoma (arrowhead in c–e) and a pancreatic NET (arrow in f).

Figure 2

Parathyroid adenomas. In two different patients, ultrasound shows a markedly hypoechoic nodule (arrow) close to the left lobe (a) and right (c) thyroid lobe. Color-doppler images highlight the feeding vessels (arrowhead) inside the lesions (b,d).

Figure 3

Parathyroid adenomas. 18F-fluorocholine PET/CT (a,b) and parathyroid scintigraphy (c,d) of two different patients show radiotracer uptake within parathyroid glands (arrows).

Figure 4

Parathyroid adenoma. Axial T2-weighted image shows a small iso-hyperintense mass behind the left thyroid lobe (arrow).

Figure 5

Cystic pancreatic NET of the tail (arrows). Fat-sat T2-weighted image (a) and T1-weighted image (b) show a cystic-like lesion in the pancreatic tail with a thick and irregular enhancing wall (c,d). PET-CT highlights high tracer uptake of the lesion (e). In the same patient, ultrasound revealed a synchronous parathyroid adenoma (f).

Figure 5

Cystic pancreatic NET of the tail (arrows). Fat-sat T2-weighted image (a) and T1-weighted image (b) show a cystic-like lesion in the pancreatic tail with a thick and irregular enhancing wall (c,d). PET-CT highlights high tracer uptake of the lesion (e). In the same patient, ultrasound revealed a synchronous parathyroid adenoma (f).

Figure 6

Insulinoma. Heterogeneously enhancing mass (arrows) in the pancreatic tail (a), with significant diffusion restriction (b,c) and avid uptake on PET-CT (d).

Figure 7

Synchronous non-functioning pancreatic neuroendocrine tumors and adrenal adenomas. Arterial phase contrast-enhanced T1-weighted images show two slightly hyperenhancing nodules (white arrows) in the pancreatic isthmus (a) and in the tail (c). Nodular thickening of the left adrenal gland (white arrowhead) was also found (c). Subsequent 68Ga-DOTATOC-PET-CT (b,d) demonstrated high uptake by the pancreatic (yellow arrows) and adrenal lesions (yellow arrowhead).

Figure 8

Pituitary micro-prolactinoma. T1-weighted MR images before (a) and after (b) contrast administration showing a hypointense and low-enhancing nodule (arrow) in the anterior pituitary gland.

Figure 9

Pituitary macro-adenoma. Sagittal plane basal CT (a) image shows a large mass causing bone remodeling of the sella turcica and thinning on the posterior wall of the sphenoid sinus (arrowhead). MRI T1-weighted images before (b) and after (c) contrast administration confirm the presence of a large hypointense lesion (arrows) arising from the pituitary gland, with heterogeneous enhancement.