Frequency of Pituitary Tumor Apoplexy During Treatment of Prolactinomas with Dopamine Agonists: A Systematic Review

Abstract

Many researches that discourse the treatment of prolactinomas with dopamine agonists (DA) provide data about pituitary tumor apoplexy of some prolactinomas. Therefore, DA are listed as risk factors for apoplexy of prolactinomas. The authors wish to explore the percentage (frequency) of pituitary tumor apoplexy during the treatment of prolactinomas with DA. From June 2011 to February 2012, we sought electronic databases and found 2169 articles and 71 book chapters relevant to DA. Only seven articles have been included into systematic review and from 4 articles we extracted numerical data that showed percentage of pituitary tumor apoplexy. One hundred and fifty-seven patients treated with DA were included in four studies. Results showed the following percentage of apoplexy during the treatment of prolactinomas with DA (apoplexy/therapy ratio): 1/84(1,19%), 13/29(44,83%), 1/15(6,67%) and 1/29(3,45%). One result stands out from the other (13/29-44,83%) because of retrospective search for pituitary hemorrhage by MRI imaging of sellar region and some of the patients were without clinical signs of apoplexy. Median and mean age of included patients was usually over 30 years. Pituitary tumor apoplexy appeared more frequently in macroprolactinomas than in microprolactinomas and also within a year and a half since the beginning of treatment with DA. Conclusively, clinically manifested pituitary tumor apoplexy appears in relatively small percentage of prolactinomas treated with DA. We were also concluded that apoplexy appears asymptomatic and because of that and because of more frequently appearing in macroprolactinomas, there are recommendations for performing MRI imaging of sellar region more often in patients with macroprolactinomas than in patients with microprolactinomas who are treated with DA.

MRI follow-up is unnecessary in patients with macroprolactinomas and long-term normal prolactin levels on dopamine agonist treatment

“…Hemorrhagic changes with no clinical symptomatology cannot be considered as a pituitary apoplexy, which, by definition, requires clinical symptoms. This explains why our rate of hemorrhagic changes on MRI was actually superior to the rate of clinical apoplexy reported in the literature (18,19,20). In our study, these hemorrhagic changes were likely due to the mechanism of action of DA, even if spontaneous hemorrhagic changes have also been reported in untreated macroprolactinomas.…”

Diagnostic pitfalls of hyperprolactinemia: the importance of sequential pituitary imaging

“…In our series, patients with non-functioning pituitary adenoma who were treated with dopamine agonist did not show tumor shrinkage, and surgery underwent for them 24.6 months after introduction of medication, on average. Moreover, the usage of dopamine agonists is one of the risk factors of pituitary apoplexy [17–20] and the hemorrhagic event is more frequent within 18 months since the beginning of dopamine agonist treatment [21]. Taken together, patients with hyperprolactinemia who were treated with dopamine agonist should be meticulously followed with MR imaging at least 24 months.…”

Clinical and imaging features of pituitary apoplexy and role of imaging in differentiation of clinical mimics

“…In addition, it is suggested that pituitary gland might have a critical perfusion pressure well below normal arterial pressure (24). It is possible that this peculiar vascularity and sudden alterations in perfusion pressure by various triggering factors (Table 1) (25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35)(36)(37), may predispose to sudden hemorrhage and/or infarction in micro adenomas as well as non-adenomatous lesions. Diabetes and arterial hypertension do not predispose patients to PA as reported in previous studies (16).…”