Wednesday, March 22, 2017
An update on SF-1 driven pituitary adenomas
Adenomas driven by the transcription factor SF-1, which are exclusively gonadotroph adenomas, are a common subtype encountered by the surgical pathologist. Traditionally, gonadotroph adenomas have been defined by positive immunostaining for luteinizing hormone (LH) and/or follicle stimulating hormone (FSH) with or without alpha-subunit (αSU). However, evidence is now emerging that replacement of these three immunostains by the single SF-1 stain results in a more cost-effective and sensitive means of detecting gonadotrophin adenomas. Further, the majority of previously classified "null cell" adenomas -- negative for all hormonal markers including LH, FSH and αSU -- are in fact positive for SF-1 and therefore better classified as gonadotroph adenomas.