Aggressive Prolactin-Secreting Pituitary Adenomas and Carcinomas

Abstract

Aggressive prolactinomas (PRL-omas) and carcinomas comprise a rare but challenging subset of pituitary tumors. Firstly, the holistic definition that reliably identifies these tumors in a prospective manner remains elusive. Although comprehensive evaluation of patient gender, age, local invasiveness, treatment responses, and histopathological features may be informative to assess the potential for PRL-oma aggressiveness, a definitive diagnosis cannot be made until disease progression is observed despite standard therapy, which typically includes medical and surgical therapy. The failed early diagnosis of these aggressive PRL-omas may delay the initiation of intensive stepwise multimodal treatments and lessen ultimate therapeutic outcomes. Secondly, even though current therapeutic options for aggressive prolactinomas are suboptimal in some cases, due to the rarity of this disease entity, large-scale clinic trials and prospective studies are impractical. Most novel therapies in this subset of tumors are based on case reports or small series, which greatly reduces their validity and limits recommendations. Randomized prospective multicenter studies would be a major advantage to identify reliable predictive diagnostic biomarkers and explore novel efficacious treatment options for these tumors. These could perhaps be conducted on a global basis though funding such an effort is a limiting factor. This chapter provides an overview of current knowledge regarding the various tools used to diagnose aggressive prolactin-secreting tumors and discusses both established and emerging therapeutic options.