<prompt> In sipple syndrome MEN II all are present except:PheochromocytomaPituitary hyperplasiaMedullary carcinoma thyroidParathyroid hyperplasia  <response>: Ans: b Pituitary hyperplasia Ref: Robbins, 7th ed,p. 222MEN 2a is characterized by pheochromocytoma, medullary carcinoma thyroid, and Parathyroid hyperplasia SYNDROMES MEN IMEN IIAMEN II BPituitaryParathyroidAdenomaHyperplasiaAdenomaCarcinomaHyperplasia Adrenal thyroidCortical hyperplasiaPheochromocytomaC cell hyperplasiaMedullary carcinomaPheochromocytomaC cell hyperplasiaMedullary carcinomaExtra endocrine changes MucocutaneousGanglioneuromaMarfanoid habitusMutant geneMEN IRETRETHirschsprung disease - loss of function in RET proto-oncogeneMEN IIA - a gain of function in RET proto-oncogene 