Skip to main content
2024 AANS Annual Scientific Meeting Main banner
Back

Tumor Rapid Fire Abstract

Tumor

Long-term Volumetric Analysis of Pituitary Microadenomas: An International, Multi-Center Cohort Study

Sunday, May 5, 2024
1:53 PM – 1:55 PM CT
Location:  S405a
Disclosure(s):
Christopher S. Hong, MD: No financial relationships to disclose
Introduction: Pituitary microadenomas (PmAs) are an increasingly incidental finding. To date, no comprehensive volumetric analyses of PmA growth patterns have been conducted. We aimed to conduct volumetric analysis of long-term changes in PmAs to evaluate potential trends in outcomes and growth patterns.

Methods: Patients who underwent ≥2 pituitary MRIs for suspected PmAs were identified retrospectively across 4 referral centers. Patient demographics, symptoms, MRIs, and treatment course were analyzed. A linear-mixed model was used to depict changes in tumor volume over time.

Results: A total of 470 patients (male=125;26.6%) referred to the 4 centers from 2003-2022 were identified. Median age at first MRI was 43 years [IQR:32–54]. Median number of MRIs per patient was 3 [IQR:2–5] and median follow-up time was 55 months [IQR:26–102]. 298 PmAs (63.4%) were solid, 102 (21.7%) were cystic, 46 (9.8%) were uncertain, and 24 (5.1%) were mixed. 74 patients (15.7%) presented with subclinical hyperpituitarism, most often hyperprolactinemia, while 66 (14.0%) experienced hypopituitarism such as hypogonadism, hypothyroidism, and growth hormone deficiency. 80 patients (17.0%) received medical therapy and 48 (10.2%) underwent transsphenoidal surgery, while the remaining were observed.

Baseline mean tumor volume was 1095.2 mm3 (SE:175.9) with significant growth rate of 50.1 mm3/year (SE:21.3;p=0.02). Among treated patients, baseline tumor volume was significantly greater at 2306.9 mm3 (SE:641.5;p < 0.003) and also significantly grew at 237.3 mm3/year (SE:92.4;p=0.01). For those observed, baseline tumor volume was significantly decreased at 675.3 mm3 (SE:58.4;p < 0.001) and demonstrated non-significant growth of 2.7 mm3/year (SE:10.6;p=0.80). When subgrouped into volumes above and below the median, those above averaged 1976.3 mm3 (SE:351.2) with statistically significant growth of 135.1 mm3/year (SE:51.8, p=0.009) versus those below averaged 246.0 mm3 (SE:38.3) with non-significant growth of 5.5 mm3/year (SE:8.1;p=0.49).

Conclusion : The majority of PmAs can be observed with long-term stability in tumor size. While PmAs with larger baseline volumes are more inclined to grow and thus undergo treatment, smaller tumors may remain stable long-term without any significant growth.