Predictors of silent corticotroph adenoma recurrence; a large retrospective single center study and systematic literature review.

PURPOSE: Silent corticotroph adenomas (SCAs) are clinically silent and non-secreting, but exhibit positive adrenocorticotropic hormone (ACTH) immunostaining. We characterized a single center cohort of SCA patients, compared the SCAs to silent gonadotroph adenomas (SGAs), identified predictors of recurrence, and reviewed and compared the cohort to previously published SCAs cases. METHODS: Retrospective review of SCA and SGA surgically resected patients over 10 years and 6 years, respectively. Definitions; SCA-no clinical or biochemical evidence of Cushing's syndrome and ACTH positive immunostaining, and SGA-steroidogenic factor (SF-1) positive immunostaining. A systematic literature search was undertaken using Pubmed and Scopus. RESULTS: Review revealed 814 pituitary surgeries, 39 (4.8%) were SCAs. Mean follow-up was 6.4 years (range 0.5-23.8 years). Pre-operative magnetic resonance imaging demonstrated sphenoid and/or cavernous sinus invasion in 44%, 33% were > 50% cystic, and 28% had high ACTH levels pre-operatively. Compared to SGAs (n = 70), SCAs were of similar size and invasiveness (2.5 vs. 2.9 cm, p = 0.2; 44 vs. 41%, p = 0.8, respectively), but recurrence rate was higher (36 vs. 10%, p = 0.001) and more patients received radiation therapy (18 vs. 3%, p = 0.006). Less cystic tumors (0 vs. 50%, p < 0.001) and higher pre-operative ACTH levels (54 vs. 28 pg/ml, p = 0.04) were predictors of recurrence for SCAs. CONCLUSION: This review is unique; a strict definition of SCA was used, and single center SCAs were compared with SGAs and with SCAs literature reviewed cases. We show that SCAs are aggressive and identify predictors of recurrence. Accurate initial diagnosis, close imaging and biochemical follow up are warranted.

Dopamine agonist therapy induces significant recovery of HPA axis function in prolactinomas independent of tumor size: a large single center experience.

Our objective was to compare prevalence and rates of recovery of hypothalamic-pituitary-adrenal axis dysfunction in prolactinoma patients before and after dopamine agonist therapy with nonfunctioning pituitary adenoma patients pre-transsphenoidal and post-transsphenoidal surgery. We retrospectively compared hypothalamic-pituitary-adrenal axis function in patients with prolactinomas naïve to dopamine agonist therapy with a cohort of nonfunctioning pituitary adenoma patients matched for gender and tumor size by classification (n = 57; 30 male/27 female; 27 microadenoma/30 macroadenoma). Patients with <52 weeks follow up, previous medical therapy, surgery, or radiation therapy were excluded. At baseline, there was no difference between groups for age, mean tumor size, or prevalence of adrenal insufficiency. Recovery from baseline adrenal insufficiency was demonstrated in patients with microprolactinomas and macroprolactinomas at a 52 week follow up (p = 0.003 and p = 0.004). These rates were similar to nonfunctioning pituitary adenoma patients after surgery. We show, in a large uniform study, that adrenal insufficiency significantly recovered after dopamine agonist treatment, independent of tumor size and gender in patients with prolactinomas naïve to therapy.