The Effect of Cabergoline Use on Pituitary Tumor Fibrosis

Introduction: Prolactinomas are a common intracranial neoplasm, accounting for most pituitary adenomas. Despite variability in their size at presentation and degree of hormonal dysregulation, medical treatment with the use of dopamine agonists, such as cabergoline and bromocriptine, often remains a first-line treatment approach. Although bromocriptine has been recognized to cause increased tumor fibrosis, the effect of cabergoline on collagen deposition has been disputed. The aim of this paper is to understand the influence of cabergoline treatment on tumor fibrosis prior to resection of prolactinomas.

Case Presentations: Five patients with prolactin-secreting adenomas who underwent surgical resection were included in this report. All five patients were males, with an average age of 36 years (range: 21–52 years). Prolactin levels at presentation ranged from 925.9 to 16,487.4 ng/mL. Four patients received cabergoline treatment for at least one month prior to surgery (range of treatment duration: 1–2 months). One patient was prescribed cabergoline but reported never taking the medication before tumor removal. Pathology reports for each sample confirmed tumor specimens to be lactotroph adenomas. Masson’s trichrome staining was performed on all tumor samples, and the percentage of fibrosis was quantified using ImageJ. Among those patients who received preoperative cabergoline, the extent of tumor fibrosis ranged from 40 to 70%. In contrast, specimen fibrosis was 15% for the patient without evidence of cabergoline use.

Conclusion: The results of this report demonstrate that preoperative administration of cabergoline causes significant fibrosis of prolactinomas. Additionally, this study provides evidence that a short duration of treatment is sufficient to induce changes in pituitary tumor collagen deposition. Understanding the effect of cabergoline on the consistency of pituitary tumors prior to surgery is important as increased levels of fibrotic tissue can lead to more difficult tumor removal, reduce the possibility of gross total resection, and increase the rate of surgical complications. Considering these effects, further studies regarding the use of surgical resection prior to cabergoline use for managing patients with prolactinomas are warranted ([Figs. 1]–[3]).

Fig. 1

Fig. 2

Fig. 3

Publication History

Article published online:
05 February 2024