Pediatric Pituitary Adenomas at the Mayo Clinic, 1975 through 2014

As an update to the publication, Pituitary adenomas in childhood and adolescence, (J Neurosurg 80:209–216, 1994) which looked at 36 pediatric pituitary adenoma surgical resections at the Mayo Clinic between 1975 and 1988: since 1975 to 2014, a total of 197 patients had pituitary adenomas were resected that were diagnosed when they were 21 years of age and under at the Mayo Clinic. 130 (66%) of these patients were diagnosed between 18 and 21 years of age. Complete pathological, laboratory and clinical data were available for retrospective review for 79 of these patients for surgeries performed between 1997 and 2014.

55 (70%) of these 79 patients were female (144 or 73% of the entire group of 197 patients since 1975 were female), which is a statistically significant increase since the original study group which also showed a female preponderance of 58%.

4 (5%) of these adenomas were nonfunctioning (including 3 with positive IHC for ACTH, and 1 for FSH), 9 (11%) secreted GH, 36 (46%) secreted prolactin, 18 (23%) secreted ACTH, 1 (1%) secreted FSH, and 9 (11%) were plurihormonal (8 of which secreted GH in addition to another hormone and 7 prolactin in addition to another hormone). All were macroadenomas except 1 (1% overall) of the ACTH secreting tumors was a symptomatic microadenoma.

8 of these showed atypical features such as elevated MIB-1 labeling, p53 staining on IHC or frequent mitoses. 5 (26% including the plurihormonal tumors secreting ACTH) of the ACTH secreting tumors were positive for Crooke's Hyaline Change.

All of these patients were alive at their last followup (which was within an average within 7 years to the current date). Of the entire 197 pediatric patients who underwent adenoma resection since 1975, only 7 are known to be dead (3.5%) which is similar to the healthy population survival rate for a group of this average age.

The relative rates of these lesions remain stable based on our small sample size of these rare tumors in the pediatric population. The findings in the original publication still stand: 1) although pediatric pituitary adenomas occur primarily in adolescence, they can occur at any age; 2) transsphenoidal surgery is feasible and safe in this age group; 3) plurihormonal tumors occur more frequently in the pediatric age group than in adults; and 4) long-term control rates in PRL- and ACTH-secreting tumors are probably similar to those seen in adults.

These distributions will be compared with those found in typical adult-onset adenoma patients for statistical significance.