Background: Cabergoline (CAB) has been proposed as the first-line treatment in the management of prolactin (PRL)-secreting tumors (prolactinoma [PRLoma]), including those resistant to standard dopamine agonist (DAA) therapy. The authors report remarkable effects of CAB in a case of huge PRLoma that had been resistant to a long-term, high-dose treatment with bromocriptine (BRC).
Case description: A 28-year-old man was originally presented with oculomotor paresis when he was 9 years old. After 2 partial resections, he was treated with a maximum 60-mg/d dose of BRC for 18 years. Nonetheless, the tumor grew up to more than 8 cm in diameter, serum PRL increased over 60000 ng/mL, and his visual acuity deteriorated. Cabergoline normalized serum PRL level, shrank the tumor mass remarkably, and caused marked improvement of visual acuity.
Conclusion: Prolactin normalization and significant tumor shrinkage could be achieved with CAB even in extremely BRC-resistant PRLomas. Surgical resection should be reserved only for patients who are resistant to cabergoline or who require urgent decompression in such emergency as massive intratumoral hemorrhage.