PNA Medical Corner: Prevalence of Clinically Silent Corticotroph Macroadenomas
This month the PNA Medical Corner focuses on an article co-written by PNA member Dr. Peter Snyder of the University of Pennsylvania. It is called the Prevalence of Clinically Silent Corticotroph Macroadenomas. The article found that 16% of large pituitary tumors treated surgically are silent corticotroph macroadenomas.
Clin Endocrinol (Oxf). 2016 Jun 27. doi: 10.1111/cen.13146. [Epub ahead of print]
Guttenberg KB1, Mayson SE1, Sawan C1, Kharlip J1, Lee JY2, Martinez-Lage M3, Loevner LA4, Ewanichak J1, Grady MS2, Snyder PJ1.
The prevalence of clinically silent corticotroph macroadenomas is unknown. Our aim was to determine the prevalence of clinically silent corticotroph macroadenomas among all pituitary macroadenomas.
Patients scheduled to have transsphenoidal surgery for any sellar mass were prospectively evaluated clinically and biochemically.
Adults who were scheduled for transsphenoidal surgery for a sellar mass at a single academic medical center.
Patients were assessed clinically prior to surgery and graded as having typical, mild or no Cushingoid features. They were assessed biochemically by plasma ACTH and 24-hour urine free cortisol (UFC). Excised tissue was examined histologically, and pituitarymacroadenomas examined by immunohistochemistry. Patients with corticotroph macroadenomas were classified as clinically silent if they exhibited no Cushingoid features but had elevated plasma ACTH and/or 24-hour UFC. They were classified as totally silent if they exhibited neither Cushingoid features nor elevated plasma ACTH or 24-hour UFC.
Of 124 patients who had pathologically-confirmed pituitary macroadenomas, twenty (16%) had corticotroph macroadenomas. Eight (40%) of these were clinically silent, in that they had no Cushingoid features but could be identified biochemically by elevated plasma ACTH (seven) and/or 24-hour UFC (three). Five (25%) were totally silent.
A substantial minority (16%) of pituitary macroadenomas treated surgically are corticotroph adenomas. Of these, 40% are clinically silent but can be recognized by elevated plasma ACTH and/or 24-hour UFC. Recognizing these adenomas may influence the surgical approach and provide a marker by which to follow the response to treatment.