Pituitary tumors have a large spectrum pathology. These "little buggers" may cause large problems, also. Dr. Shereen Ezzat of the Toronto Cancer Institute has been studying pituitary tumors for several years, and presents the case for epigenetic disruption of gene expression which causes alterations of normal pituitary cells. Using the information he and others have gathered, he is hopeful treatments for these lesions/tumors can be developed. Since the morbidity/mortality of most with pituitary tumors is greatly increased, and the only long-term therapies so far are surgical or radioactive, improved treatment is anxiously sought by those of us with Cushing's or presently in remission.
According to Dr. Ezzat, pituitary tumors comprise 10% of the tumors surgically removed intercranially with increased morbidity due to invasion of surrounding structures. As a Cushie community, we know this only too well first-hand. All too often the only recourse for the hypercortisolemia due to ACTH producing tumor cells is a bilateral adrenalectomy. Radiation is often a secondary treatment to decrease tumor growth or Nelson's syndrome.
In another article, Dr. Ezzat says, "Some pituitary adenomas grow rapidly, producing symptoms of an intracranial mass, loss of normal anterior pituitary hormone production, and visual-field disturbances due to stretching of the overlying optic chiasm. They can invade downward into paranasal sinuses, laterally into the cavernous sinuses (thereby disrupting coordinated eye movement) and upwards into the brain. They can cause death by invasion of the brain."
But size does NOT always matter with these tumors. Dr. Ezzat also says "they can cause mood disorders, sexual dysfunction, infertility, obesity and disfigurement, hypertension, diabetes mellitus and accelerated heart disease. If untreated, hormone-excess syndromes can be lethal."
In the pre-print, recent article, Epigenetic Control in Pituitary Tumors , Dr. Ezzat discusses epigenetically-mediated gene dysregulation as a cause for the production of pituitary tumors. He explores the role of fibroblast growth factors and histone gene silencing and discusses the implications of the need to find the process or mechanism involved in order to develop new therapies.
Shereen Ezzat, M.D. (2008). Epigenetic Control in Pituitary Tumors Endocrinology Journal DOI: http://dx.doi.org/http://www.jstage.jst.go.jp/article/endocrj/advpub/0/0804240101/_pdf