Purpose: Somatotrophinomas have been shown to demonstrate T2-weighted signal intensity (WSI) on MRI that is correlated with clinicopathological findings and response to treatment. Therefore, we aimed to investigate these correlations in functional pituitary adenomas, including prolactinoma and corticotrophinoma. Material and Methods
Patients with somatotrophinoma (n=87), prolactinoma (n=78) and corticotrophinoma (n=33) were involved in this study. The initial T2-WSI findings (grouped into hypo-, iso- and hyperintense) were compared with hormon levels, tumor diameter, granulation patterns and treatment response.
While most of somatotrophinomas were hypointense, most of prolactinomas and corticotrophinomas were hyperintense. Tumor diameter was significantly larger in hyperintense somatotrophinomas than in hypointense group (P=0.007), but the tumor diameter in the isointense group did not show any difference when compared to the others. IGF-1% ULN (upper limit of normal) was higher in hypointense somatotrophinomas than the other two groups (P=0.02). Sparsely granulation pattern in hyperintense somatotrophinomas and densely granulation pattern in hypointense somatotrophinomas are more frequent (P=0.035), whereas the granulation pattern distribution in isointense group did not differ from the other two groups. The hormonal response to somatostatin analogs (SSA) treatment (percentage of IGF-1 reduction) was higher in the hypointense group than in the other two groups (P=0.04). The tumor diameter was smaller in the hyperintense prolactinomas than in the other groups (P=0.039), but the basal PRL levels were not different between the groups. The response to dopamine agonist (DA) treatment of iso- and hyperintense prolactinomas is much better than the hypointense group (P<0.001). Tumor diameter was larger in hyperintense corticotrophinomas than the other two groups (P=0.012), but there was no difference between the baseline cortisol and ACTH levels of the groups. Sparsely granulation pattern was higher in hyperintense corticotrophinomas and densely granulation patern in hypointense corticotrophinomas (P=0.029), whereas granulation pattern distribution in isointense group was not different from the other two groups. There was no difference between the groups in terms of remissions and recurrences.
Hyperintense somatotrophinomas support literature knowledge with increased tumor diameter, sparsely granulation pattern and less responsiveness to SSA treatment. The response to DA treatment of iso- and hyperintense prolactinomas is much better, but there was no difference between the groups in terms of remissions and recurrences in corticortophinomas. Our results in prolactinomas and corticotrophinomas should be supported by further studies.
20 May 2017 - 23 May 2017