A comparative, population-based analysis of pituitary incidentalomas vs clinically manifesting sellar masses

Sellar masses may present either with clinical manifestations of mass effect/hormonal dysfunction (CMSM) or incidentally on imaging (pituitary incidentaloma (PI)). This novel population-based study compares these two entities.

Retrospective analysis of all patients within a provincial pituitary registry between January 2006 and June 2014.

Nine hundred and three patients were included (681 CMSM, 222 PI). CMSM mainly presented with secondary hormone deficiencies (SHDs) or stalk compression (29.7%), whereas PIs were found in association with neurological complaints (34.2%) (P < 0.0001). PIs were more likely to be macroadenomas (70.7 vs 49.9%; P < 0.0001). The commonest pathologies among CMSM were prolactinomas (39.8%) and non-functioning adenomas (NFAs) (50%) in PI (P < 0.0001). SHDs were present in 41.3% CMSM and 31.1% PI patients (P < 0.0001) and visual field deficit in 24.2 and 29.3%, respectively (P = 0.16). CMSM were more likely to require surgery (62.9%) than PI (35.8%) (P < 0.0005). The commonest surgical indications were impaired vision and radiological evidence of optic nerve compression. Over a follow-up period of 5.7 years for CMSM and 5.0 years for PI, tumour growth/recurrence occurred in 7.8% of surgically treated CMSM and 2.6% without surgery and PI, 0 and 4.9%, respectively (P = 1.0). There were no significant differences in the risk of new-onset SHD in CMSM vs PI in those who underwent surgery (P = 0.7) and those who were followed without surgery (P = 0.58).

This novel study compares the long-term trends of PI with CMSM, highlighting the need for comprehensive baseline and long-term radiological and hormonal evaluations in both entities.