This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Disorders of pituitary gland, Subject name: Medicine
Which is the most common cell involved in non-functioning pituitary adenoma? 
Select and explain. 
A. Gonadotropin producing cell, B. Prolactin producing cell, C. GH producing cell, D. TSH producing cell
A: Gonadotropin producing cell
Answer: A: Gonadotropin producing cell 
Explanation: A majority of pituitary adenomas are clinically non-functioning and produce no distinct clinical hyper-secretory syndrome. Some of them arise from gonadotrope cells and may secrete intact circulating gonadotropins. most common cell involved in Non-functioning pituitary adenoma is Gonadotropin producing cell. The most common Secretory adenoma is Prolactinoma. The least common secretory adenoma is TSH secreting tumor.