Endocrine Abstracts

Introduction: Pituitary incidentalomas are lesions discovered on an imaging study performed for an unrelated reason. Their frequency varies among 0.2–38% and it is continuously increasing due to the development of neuroimaging techniques. The aim of the study is to investigate clinical and biochemical characteristics of 205 consecutive patients (70% female, mean age 53.6±18.2 years) with incidental pituitary adenoma (IPA) followed at our center from 1990 to present.

Methods: In all patients, hormonal evaluation (basal anteropituitary function, ACTH 250 mg stimulatory test, other dynamic tests when indicated) and pituitary imaging were performed at baseline, 6 months later and then annually if there was no other specific indication. Seventy patients were also screened for subclinical hypercortisolism (cortisol after 1 mg overnight dexamethasone suppression test (1 mg DST), late-night salivary cortisol, 24-hours urinary free cortisol).

Results: At diagnosis, 39% of patients had macroadenomas. One or more pituitary deficiencies were observed in 14.3% of cases (macro 28.6 vs micro 5.6%, P<0.05). Hyperprolactinemia (<100 ng/ml) was observed in 13.9% of patients (macro 15.5 vs micro 12.8%, P NS). Subclinical hypercortisolism was found in 3/70 (4.2%) patients studied, all with macroadenomas. One hundred and ten patients had a follow-up longer than 12 months with a mean follow-up of 4.9 years. Radiological evaluation revealed a significant increase in tumor mass in 19/110 patients (17.3%, 13 macro vs 6 micro, P NS) and a reduction in 5.4% (all microadenomas). The volumetric increase occurred in 88% of patients during the first 2 years after diagnosis. Additional pituitary deficiencies were observed in 3% of patients during follow-up. Overall, 18% of patients were treated with trans-sphenoidal adenomectomy owing to initial mass size or for their rapid increase.

Conclusions: Our data confirm that patients with IPA need for a close radiological and hormonal follow-up. In addition, we suggest exclusion of subclinical hypercortisolism in such patients.