Case report: A giant prolactinoma (size=5.2×4.1×3.2 cm; PRL=6 400 ng/mL) was diagnosed in an amenorrheic 19-year old girl who presented to the emergency room complaining of headaches and bilateral decrease in visual acuity for 10 days. The patient was started on cabergoline (CAB) in progressive doses up to 3 mg/week. PRL levels decreased from 6 400 to 4 600 ng/dl within 60 days, with improvement of visual complaints and visual fields defects. The dose was subsequently increased up to 6 mg/week over the next 6 months but PRL did not normalize (1 840 ng/dl) and amenorrhea persisted. A new pituitary MRI was performed revealed a ~50% tumor reduction. Six months later, worsening of visual fields and a 20% increase in tumor volume were detected, whereas PRL levels increased to 2 270 ng/ml. A transsphenoidal surgery (TSS) was therefore undertaken (Ki-67 expression=8%), which led to a ~30% reduction of tumor volume whereas PRL levels decreased from 2 270 to 1 210 ng/dl within 4 months. CAB was restarted but PRL did not normalize (520 ng/dl), despite the use of doses up to 4 mg/week (maximal tolerated dose) for 6 months, and amenorrhea persisted. Lanreotide autogel (120 mg every 28 days) was added to CAB (4 mg/week). The combined treatment was well tolerated and lead to decrease of PRL levels to 91 ng/ml (NR: 2.829.2) within 8 months, as well as to resumption of a regular menstrual cycle.Moreover, the combination of CAB+lanreotide autogel enabled further tumor shrinkage but invasion of both cavernous sinuses persisted. CAB dose could be subsequently reduced to 3 mg/week.
20 - 23 May 2017
European Society of Endocrinology