Pregnancy-induced prolactinoma enlargement

A 23-year-old woman at 22 weeks' gestation presented to our hospital with the chief complaint of a headache.Four years prior, she had been diagnosed with an 11 mm prolactinoma (Figure 1a), which manifested with galactorrhea and an elevated prolactin level (60.7 ng/ml, reference range: 3.5-32.7 ng/ml).Despite the tumor size remaining stable, her prolactin levels declined to �20 ng/ml after initiating treatment with cabergoline at a dose of 1 mg/week.However, she discontinued the medication on her own 6 months prior to her current presentation.Magnetic resonance imaging revealed significant tumor enlargement (19 mm), now encroaching upon the optic chiasm (Figure 1b).With persistent headaches, cabergoline treatment was restarted at 0.5 mg/week despite her pregnancy.This intervention stabilized the tumor size and alleviated her headaches.At 38 weeks of gestation, she delivered a healthy female neonate via a scheduled cesarean section.Postpartum, the cabergoline dose was incrementally increased to 3 mg/week, reducing prolactin levels to around 10 ng/ml.Follow-up imaging 1 year postpartum demonstrated a reduction in tumor size to 16 mm (Figure 1c), and 2 years postpartum, the tumor had receded to become nearly imperceptible (Figure 1d). Figure 1.Coronal scan of T1-weighted magnetic resonance imaging of hypothalamic-pituitary regions (a) at the initial diagnosis of a prolactinoma, (b) at the presentation of 22 weeks' gestation, (c) 1 year postpartum, and (d) 2 years postpartum.