Current Status of Diagnosis and Management for Functioning Pituitary Tumors: Part I

Pituitary adenomas (PA) account for approximately 15% of all intracranial neoplasms. Pituitary adenomas can be of different subtypes based on the cell of origin or associated hormone hypersecretion (non-functioning pituitary adenoma, prolactinoma, somatotropinoma, corticotropinoma, thyrotropinoma, and gonadotropinoma). Functioning PAs are associated with relatively higher morbidity and mortality because of associated hormone hypersecretion syndromes. Diagnosis of functioning PA is established by biochemical confirmation of hormone hypersecretion and demonstration of a pituitary lesion on imaging. Trans-sphenoidal surgical resection of tumor represents the first-line treatment for most tumor types, except for prolactinomas where medical therapy with dopamine agonists is preferred. Radiotherapy (RT) and medical therapy are the other options for the management of PA. It is important to individualize treatment options based on tumor type, patient's clinical condition, expertise of surgeon, affordability and patient preferences. In the first part of this series, we review the presentation and management of adrenocorticotropic hormone secreting, gonadotropin secreting and aggressive PA. Despite several recent advances, the diagnosis and management of Cushing's disease is still a challenge. Modifications in magnetic resonance imaging techniques like volume interpolated 3D spoiled gradient echo sequence have improved the sensitivity to detect microcorticotropinomas. Pituitary RT, preferably conventional RT, is a useful second-line therapy for the management of CD. Besides the conventional drugs, few drugs such as pasireotide and osilodrostat have been approved by US FDA recently, whereas several others are in pipeline which provide hope for a better outcome in CD patients. Temozolomide is a useful drug for the management of aggressive PA.