<prompt> All are involved in MEN IIA except:PituitaryParathyroidThyroidAdrenal  <response>: a. PituitaryRef: Nelsons 20e p 2694-2481, Ghai 8e p 523In Multiple Endocrine Neoplasia MEN IIA, features seen are: HAPPY, i.e. Hirschsprung disease, Amyloidosis, Pheochromocytoma, Parathyroid hyperplasiaAdenoma and thyroid Carcinoma Medullary. 