Reconsideration of Surgical Indication for Prolactin-producing Pituitary Tumor Focusing on Visual Impairment

Prolactin-producing pituitary tumor (PRLoma) is the most prevalent functional pituitary tumor. If the tumor becomes large, vision can be impaired. In contrast to other pituitary tumors, cabergoline (CAB) is extremely effective for PRLoma and has become the first-line treatment. In this study, we examined our experience with the pharmacological and surgical management of PRLomas with visual impairment (VI) to determine whether VI could be a surgical indication. Further, we discussed the function of surgery in situations where the gold standard of PRLoma treatment was CAB administration. Of the 159 patients with PRLomas (age, 13-77 [mean = 36.3] years; men, 29; women, 130) at Tokyo Women's Medical University Hospital from 2009 to 2021, 18 (age, 15-67 [mean = 35.8] years; men, 12; woman, 6) had VI (subjectively, 12; objectively, 6). They started CAB treatment immediately (maximum dose: 0.5 to 6 mg/week; average: 2.17 mg/week). VI improved in 16 patients (88.9%) but did not improve in 2 (11.1%) requiring surgeries. One of the two patients had a parenchymal tumor resistant to CAB, and the other had a cystic tumor due to intratumoral bleeding. Consequently, CAB is the first-line treatment for PRLomas with VI because of its significantly high rate of improvement. However, close and rigorous surveillance is necessary for cases resistant to CAB, and the correct decision is required regarding surgical interventions at proper timing and appropriate surgical approaches considering the purpose of surgery.