Long-Term Changes in the Size of Pituitary Microadenomas

Different tumor growth pattern of clinically nonfunctioning pituitary neuroendocrine tumor according to sex and age: a longitudinal study

PURPOSE

Asymptomatic patients with clinically non-functional pituitary neuroendocrine tumors (CNF-PitNETs) are usually followed up. However, the natural course of CNF-PitNETs according to sex and age remains unclear. Therefore, this study assessed growth patterns of CNF-PitNETs according to sex and age.

METHODS

In this longitudinal study, we enrolled 431 consecutive patients with CNF-PitNETs who were treated at Seoul National University Hospital from 1997 to 2021. The patients underwent hormone function testing and visual field testing, and were subsequently followed up with imaging over a median duration of 66 months.

RESULTS

The median age of the patients was 53.0 years, and 37.1% (n = 160) were men. Men were older and harbored more macroadenomas than women. The annual tumor volume change was higher in men than in women (0.21 vs. 0.04 cm3/year, P < 0.001). The estimated cutoff value of age for significant tumor growth was 51 years. In men, the annual tumor volume change was similar across all age groups. In women, those aged ≤ 50 years showed significantly lower annual tumor volume change than those aged > 50 years (0.01, 0.11, and 0.17 cm3/year, P = 0.001). When comparing sexes within the same age group, the annual tumor volume changes was significantly lower for women than for men, only in patients aged ≤ 50 years (0.01 vs. 0.15 cm3/year, P < 0.001).

CONCLUSIONS

Among patients with CNF-PitNET, tumor growth was slower in women aged ≤ 50 years than in men and women aged > 50. These findings may guide the customization of surveillance strategies for CNF-PitNETs according to sex and age.

How often should we perform magnetic resonance imaging (MRI) for the follow-up of pituitary adenoma?

Magnetic resonance imaging (MRI) is the examination of choice for diagnosing and monitoring pituitary adenoma (also known as pituitary neuroendocrine tumor or PitNET), whether treated or not. However, repeating the examination too often (and sometimes unnecessarily) is costly, and worrying data on tissue accumulation (brain, bone, etc.) of gadolinium atoms dissociated from their carrier molecule (chelator) have led European authorities to ban contrast agents based on linear chelators of gadolinium, which are particularly susceptible to rapid dissociation, in favor of chemically more stable macrocyclic chelators. It is therefore important to determine the optimal frequency for pituitary MRI monitoring in order to safely assess the natural history or therapeutic response of pituitary adenomas. The aim of this article is to summarize the most recent data on optimal follow-up intervals depending on the type, size and location of the pituitary tumor and the clinical situation in general, in order to generate monitoring algorithms to guide clinicians.