Which biochemical tests should be performed to screen for the different types of MEN syndromes?

To screen for the different types of multiple endocrine neoplasia (MEN) syndromes, specific biochemical tests are performed based on the endocrine glands commonly affected in each syndrome.

Multiple Endocrine Neoplasia Type 1 (MEN1)

• The most common manifestation of MEN1 is primary hyperparathyroidism, which affects nearly all patients by age 50 [1, (Hu et al., 2021)]. Screening involves measuring serum calcium and parathyroid hormone (PTH) levels [1, (Brandi et al., 2025)].
• Pancreatic neuroendocrine tumors (PNETs) are also common in MEN1 [1, (Hu et al., 2021)]. Biochemical screening for functional PNETs may include fasting gastrin for gastrinomas, insulin and glucose for insulinomas, and potentially glucagon, vasoactive intestinal peptide (VIP), or somatostatin for other rare functional tumors [1, (Hu et al., 2021)].
• Pituitary adenomas occur in a significant proportion of MEN1 patients [1, (Hu et al., 2021)]. Screening involves measuring prolactin levels, and if indicated, insulin-like growth factor 1 (IGF-1) or other pituitary hormone levels depending on suspected tumor type [1, (Hu et al., 2021)].

Multiple Endocrine Neoplasia Type 2 (MEN2)

• Medullary thyroid carcinoma (MTC) is a hallmark of MEN2 [1, (Hu et al., 2021)]. Screening for MTC involves measuring serum calcitonin and carcinoembryonic antigen (CEA) levels [1, (Hu et al., 2021)].
• Pheochromocytomas are common in MEN2, particularly MEN2A and MEN2B [1, (Hu et al., 2021)]. Screening for pheochromocytoma involves measuring plasma or 24-hour urinary fractionated metanephrines and normetanephrines [1, (Hu et al., 2021)].
• Primary hyperparathyroidism can occur in MEN2A [1, (Hu et al., 2021)]. Screening for this involves measuring serum calcium and parathyroid hormone (PTH) levels [1, (Hu et al., 2021)].

Multiple Endocrine Neoplasia Type 4 (MEN4)

• MEN4 is caused by mutations in the CDKN1B gene and shares clinical features with MEN1 [1, (Hu et al., 2021)]. Therefore, biochemical screening for MEN4 would involve similar tests to MEN1, including serum calcium and PTH for parathyroid adenomas, and screening for pituitary and neuroendocrine tumors as clinically indicated [1, (Hu et al., 2021)].