Our experience in prolactinomas larger than 60mm

Introduction: Giant prolactinomas (tumor size larger than 40mm) are a rare entity of benign nature. Prolactinomas larger than 60mm are usually underrepresented in published studies and their clinical presentation, outcomes and management might be different from smaller giant prolactinomas.

Patients and methods: We retrospective collected data from patients with prolactinomas larger than 60mm in maximum diameter and prolactin (PRL) serum levels higher than 21,200μIU/mL in our series of prolactinomas (283). Data were collected from January 2012 to December 2017. We included three patients with prolactinomas larger than 60mm.

Results: At diagnosis, two patients presented neurological symptoms and one nasal protrusion. All patients received medical treatment with dopamine agonists. No surgical procedure was performed. Median prolactin levels at diagnosis was 108,180 [52,594-514,984]μIU/mL. Medical treatment achieved a marked reduction (>99%) in prolactin levels in all cases. Tumor size reduction (higher than 33%) was observed in all cases. In one patient cerebrospinal fluid (CSF) leak was observed after tumor shrinkage.

Conclusions: Dopamine agonists appear to be an effective and safe first-line treatment in prolactinomas larger than 60mm even in life-threatening situations. More studies with a higher number of patients are necessary to obtain enough data to make major recommendations.