Change in the immunophenotype of a somatotroph adenoma resulting in gigantism.
BACKGROUND
Examining the pathologic progression of a pituitary adenoma from the point of a prepubescent child to an adult with gigantism affords us an opportunity to consider why patients may develop secretory or functioning tumors and raises questions about whether therapeutic interventions and surveillance strategies could be made to avoid irreversible phenotypic changes.


METHODS
A patient underwent a sublabial transsphenoidal resection for a clinically non-functioning macroadenoma in 1999. He underwent radiation treatment and was transiently given growth hormone (GH) supplementation as an adolescent. His growth rapidly traversed several percentiles and he was found to have elevated GH levels. The patient became symptomatic and was taken for a second neurosurgical procedure. Pathology and immunohistochemical staining demonstrated a significantly higher proportion of somatotroph cells and dense granularity; he was diagnosed with a functional somatotroph adenoma.


CONCLUSIONS
While it is likely that the described observations reflect the manifestations of a functional somatotroph adenoma in development, it is possible that pubertal growth, GH supplementation, its removal, or radiation therapy contributed to the described endocrine and pathologic changes.
Department of Neurosurgery, Perelman School of Medicine at the University of Pennsylvania, 3 Silverstein Building, 3400 Spruce Street, Philadelphia PA 19104, USA.
Jayesh P
JP
Thawani
Department of Neurosurgery, Perelman School of Medicine at the University of Pennsylvania, 3 Silverstein Building, 3400 Spruce Street, Philadelphia PA 19104, USA.
Robert L
RL
Bailey
Division of Endocrinology, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, 100 Centrex Building, 3400 Spruce Street, Philadelphia PA 19104, USA.
Carrie M
CM
Burns
Department of Neurosurgery, Perelman School of Medicine at the University of Pennsylvania, 3 Silverstein Building, 3400 Spruce Street, Philadelphia PA 19104, USA.
John Y K
JY
Lee
Gigantism; growth hormone; non-functional adenoma; pituitary adenoma; somatotroph adenoma