Abstract
BACKGROUNDMagnetic resonance imaging (MRI) is regarded as the modality of choice in diagnosis of pituitary adenomas. Since surgery is the first line therapy for all pituitary adenomas with exception of prolactinoma, simple and reproducible MRI classification based on major directions of tumour growth is an essential tool providing the exact road map for right surgical approach and maximum safe resection.SIPAP MRI classification for pituitary adenomas is derived from KNOSP-STEINER classification of parasellar growth, to which has been added grading for superior, inferior, anterior and posterior tumour extension.We, therefore, propose to incorporate SIPAP classification in routine reporting template of pituitary adenomas, for ideal radiological description of tumour delineation, relationship to juxtasellar structures, and tumour size, hence facilitating greater success rate in surgical and subsequent clinical management.METHODSTwo radiologists retrospectively reviewed imaging of 49 patients with biopsy-proven pituitary macroadenoma and graded according to SIPAP classification. Study was conducted at Aga Khan University Hospital from 1st July 2019 to 30th June 2020. Data was analyzed using Stata version 15. Interobserver variability was calculated using Cohen’s Kappa. Comparison between grading before and after treatment was performed by Chi-square test. P values <0.05 were considered statistically significant.RESULTSSixty three percent patients were male and 37% female. Overall, maximum preoperative and postoperative volume was 71.82 cm3 and 49.50 cm3 respectively, with significant difference in pre and post-operative volumes (14.1±17.7 vs. 4.5±10.4, p-value <0.001). Length showed most significant difference pre and post-operatively (2.4±1.1 vs. 1.3±1.1, p-value <0.001). Individual tumour extensions according to SIPAP for pre- and post-operative grading showed significant difference (p-value <0.001), except for anterior extension. For suprasellar extension, 67.3% patients had pre-operative grade 3 and 63.3% had post-operative grade 0. For infrasellar extension, 51.0% had pre-operative grade 2 and 71.4% had post-operative grade 0. Anterior, posterior and parasellar extensions showed increased frequency in grade 0 in post-operative stage compared to pre-operative. Substantial inter-observer agreement was achieved for Superior, Inferior, Anterior and Posterior extent with all Kappa statistics values above 0.7 (p-value <0.001).CONCLUSIONWe propose incorporating simple and objective SIPAP classification in routine MR reporting for ideal pituitary tumour delineation, relationship to juxtasellar structures and tumour size.
Pareidolia in Neuroendocrinology: A Pituitary Macroadenoma Resembling “Big Bird”