Tumor Type Tumor Subtype Hormone Prevalence in MEN1 Syndrome Parathyroid NA 1 PTH 100 have primary hyperparathyroidism by age 50 yrs 2 Anterior pituitary Functioning Prolactinoma (PRLoma) ~10-603 have anterior pituitary tumors Most commonly seen anterior pituitary tumor subtype Growth hormone (GH)-secreting 5 of anterior pituitary tumors 4 GH/PRL-secreting 5 of anterior pituitary tumors 4 ACTH-secreting 2 4 TSH-secreting Rare 5 Nonfunctioning -   Well-differentiated endocrine Functioning Gastrinoma Accounts for 40 of well-differentiated endocrine tumors 6 Insulinoma 10 4 Glucagonoma 2 4 VIPoma 2 4 Nonfunctioning - 55 Carcinoid Bronchial No 10 Thymic No Adrenocortical Functioning Cortisol-secreting ~20-40 have adrenocortical tumors Rare Aldosterone-secreting Rare Nonfunctioning -   Skin Lipomas Angiofibromas Collagenomas - - - (30) (85) (70)   Nervous Central System Meningiomas Ependymomas - - (~8) (1)   Others Leiomyoma Pheochromocytoma - Epinephrine, Norepinephrine   1 <1 Rare Rare

Table 1: Endocrine and non-endocrine tumor types and their prevalence in MEN1 syndrome