[Pattern of invasive growth of pituitary adenomas with positive hormonal immunohistochemistry].

Background: Pituitary adenoma is the most frequent tumor of the selar region, it is generally benign, however, invasive growth towards parasellar and/or suprasellar can affect important structures causing high morbimortality.

Objective: To determine the invasive growth pattern of pituitary adenomas and its relationship with positive immunohistochemistry hormonal markers.

Material and methods: In the period from March 2020 to March 2022, patients of both sexes, older than 18 years, with histopathological diagnosis of pituitary adenoma, with immunohistochemistry report and contrasted magnetic resonance imaging were included. They were classified into invasive and non-invasive according to Knosp and Hardy classifications by MRI and according to hormonal immunohistochemistry as positive or negative.

Results: 50 cases fulfilled the inclusion criteria. 28 adenomas (56%) with positive hormonal immunohistochemistry and 22 adenomas (46%) with negative hormonal immunohistochemistry. The invasive growth pattern was as follows 50% parasellar according to Knosp classification and 74% suprasellar according to Hardy classification. We did not observe any relationship between invasive behavior and positive hormonal immunohistochemistry.

Conclusions: The incidence of pituitary adenoma by sex and age was very similar to the international literature, being more frequent in females and by age between 30 and over 60 years. The most frequent invasive growth pattern was suprasellar by Hardy classification. We did not observe a significant relationship between supra or parasellar invasive growth pattern and positive hormonal immunohistochemistry. Interestingly, there is a significant relationship between non-invasion of the cavernous sinus and less recurrence.