Natural history of nonfunctioning pituitary macroadenomas followed without intervention: A retrospective cohort study

Abstract

Objective The treatment strategy for nonfunctioning pituitary adenomas (NFPA) includes surgery, radiotherapy, medical treatment, or follow‐up. Prior series of patients with NFPAs followed without intervention include small numbers of patients with macroadenomas. This study investigated the natural history of patients with macroadenomas followed without treatment. Design and patients Retrospective cohort study included patients>18 years, with a diagnosis of NFPA ≥ 10 mm who were naïve to surgery or medical treatment and followed more than 12 months after diagnosis. Patients with chiasmal threat were excluded. Follow‐up terminated if the patient underwent surgery, received cabergoline or was lost to follow‐up. Measurements Data collected included evaluation of tumour characteristics and size by MRI, symptoms including visual disturbances, and hormonal levels. Tumour growth was defined as maximal diameter increase of ≥2 mm. Results The cohort included 49 patients (30 males, mean age 68.0 ± 12.0 years). At diagnosis, the average tumour size was 17.8 ± 5.9 mm. Mean follow‐up time was 4.9 ± 4.9 years. Increase in tumour size occurred in 16 patients (33%), with an average growth of 5.1 ± 4.4 mm. Reduction in tumour size occurred in 10 patients (20%), with a mean decrease of 3.5 ± 1.3 mm. Twenty‐three patients remained with stable tumours. Overall, 33 patients (67%) were observed without any intervention; 3 patients were operated and 13 were treated with cabergoline. None of the parameters including age, gender, baseline tumour size, invasiveness, visual disturbances, or hypopituitarism at diagnosis, predicted tumour growth. Conclusion Observation of NFPAs without surgery or medical therapy is a reasonable approach in selected patients. In our study, no parameter predicted tumour growth.

Natural history and surgical outcome of incidentally discovered clinically nonfunctioning pituitary macroadenomas

“…Of note, we did not find any clinical, biological, or radiological predictive factor clearly associated with the risk of tumor growth in these patients (although younger age showed a tendency to be associated with tumor growth). This is in keeping with the current literature, where no known predictor of growth exists a part from the size of the adenoma itself ( 19 , 20 , 21 ).…”

“…We observed higher growth rates as the follow-up gets longer (17% for follow-up <4 years and 34% for follow-up 5−8 years in the review by Huang and Molitch ( 8 ) and 12.5% per year in the meta-analysis by Fernández-Balsells et al ( 9 )). It is, however, slightly higher than those reported in other incidentaloma cohorts (23–33% ( 5 , 7 , 19 )). Selection bias might explain this difference: other studies sometimes looked at all types of pituitary incidentalomas (including Rathke’s cleft cysts or meningiomas) that might grow less.…”