3 Tesla intra-operative MRI as an adjunct to endoscopic pituitary surgery: an early assessment of clinical utility.

BACKGROUND: Extent of resection is a major determinant of outcomes following pituitary surgery. Intra-operative magnetic resonance imaging (iMRI), provides an immediate assessment of the extent of resection, allowing further tumour resection during the same procedure. However, such systems are expensive and significantly increase operative time, prompting some authors to question the additional benefit conferred by iMRI when combined with endoscopy. Our aim was to assess the impact of combining 3 T iMRI with endoscopy in patients with pituitary tumours. METHODS: We retrospectively reviewed a prospectively maintained database to identify patients who underwent iMRI guided endoscopic resection of pituitary tumours between May 2017 and November 2018 (iMRI cohort). This cohort was compared with a pre-iMRI cohort of patients who underwent endoscopic resection of pituitary adenomas. Operative time, extent of resection, control of endocrine disease and post-operative complications were recorded and analysed. RESULTS: Thirty-seven patients were included in each cohort. iMRI facilitated additional tumour resection in 6/37 (16%) of cases. In 4/37 cases (11%), iMRI prompted a return to theatre but no further tumour could be identified. The overall GTR rate, following iMRI was 24/37 (65%) as compared to 21/37 (57%) in the pre-iMRI cohort. Cure of endocrine disease associated with hormonally active tumours was achieved in 9/11 (82%) of cases in the iMRI cohort. The mean operative time in the iMRI cohort was 327 minutes (five hours 27 minutes). CONCLUSIONS: 3 T iMRI provides immediate identification of residual tumour following endoscopic pituitary surgery. This allows for resection of surgically accessible residual disease during the same procedure and is likely to reduce the requirement for later re-intervention. However, the use of iMRI in this setting is associated with significant resource allocation issues which must be considered prior to the widespread adoption of this technique.

Gender-affirming hormone therapy associated with multiple meningiomas and atypical histology in a transgender woman.

We present a 69-year-old transgender woman who underwent gender-affirming surgery in 1998 and gender-affirming hormone therapy (cyproterone acetate (CPA) and estradiol) since this time. Following an MRI scan to investigate tremor in 2013, an incidental left anterior clinoid and right petrous meningioma were identified. Subtotal surgical resection was achieved for the anterior clinoid meningioma (WHO grade 1, meningothelial subtype). At follow-up in 2016, an olfactory groove meningioma and left greater wing of sphenoid meningioma were identified. By 2017, both tumours, along with the petrous meningioma, demonstrated significant growth. In 2018, clinical decline was evident and MRI demonstrated further tumour growth. Surgery was scheduled and the olfactory groove meningioma was completely resected (WHO grade 2, chordoid subtype). Hormones were stopped, after which regression of the petrous meningioma was observed. This case demonstrates an association between high-dose CPA and estradiol and the development, growth and regression of meningiomas in a transgender woman.