Epidemiology and radiological geometric assessment of pituitary macroadenomas : population-based study

Abstract

CONTEXT: Pituitary adenomas are relatively common tumours with diverse clinical features. Epidemiological data are important to help quantify health burden.

OBJECTIVE: To provide in-depth epidemiological data on macroadenomas and radiologically characterize macroadenomas.

DESIGN: Population-based retrospective analysis, Prevalence as at 2014; Incidence based on data from 2000 to 2014, Retrospective analysis of baseline MRI.

SETTING: The Maltese islands.

PATIENTS: 173/136 patients with macroadenomas for prevalence/incidence estimates respectively, 122 baseline MRI for radiological characterization.

MAIN OUTCOME MEASURES: Prevalence rates, Standardized Incidence rates (SIR), MRI findings.

RESULTS: The prevalence for macroadenomas was 40·67/100 000 people and the SIR was 1·90/100 000/year. Giant pituitary adenomas (>40 mm) constituted 4·8% of the whole cohort of PAs and the SIR was 0·18/100 000/year. Giant prolactinomas constituted 4·7% of all the prolactinomas and the SIR was 0·07/100 000/year, while giant NFPA constituted 6·0% of all NFPA and the SIR was 0·12/100 000/year. There was a statistically significant difference in the degree of suprasellar extension (P < 0·001) and infrasellar extension (P = 0·028) between the different macroadenoma subtypes and in the vertical extension indices (median vertical extension index NFPA 3·0 mm; PRLoma −7·7 mm; GH-secreting PA −1·7 mm; P < 0·001). Pituitary macroadenomas with cavernous sinus invasion were statistically significantly larger than those without cavernous sinus invasion (P < 0·001). NFPA had predominantly a superior extension into the cavernous sinus (63·6%) compared to the functional PAs which had predominantly an inferior extension into the cavernous sinus (59·1%) (P = 0·032).

CONCLUSIONS: The various macroadenoma subtypes' epidemiological data are presented and differences between growth patterns among the various subtypes are highlighted.