The Incidence of Anterior Pituitary Hormone Deficiencies in Patients with Pituitary Microadenoma and Idiopathic Hyperprolactinaemia. A Retrospective Single Centre Study

Abstract

Introduction: Patients with microprolactinoma and idiopathic hyperprolactinaemia are not generally considered to be at risk of hypopituitarism and are therefore not routinely screened for this abnormality. Aims: We aimed to establish the frequency and clinical significance of anterior pituitary hormone deficiencies, comparing patients with radiologically proven microprolactinomas and idiopathic hyperprolactinaemia. Study Design: We retrospectively examined the case notes of 242 patients with hyperprolactinaemia from our centre. Patients who did not fit the profile of surgically naïve microprolactinoma or idiopathic hyperprolactinaemia or who had incomplete data were excluded, resulting in a study group of 185 patients. Results: Out of 242 patients, 185 patients were identified with microprolactinoma and idiopathic hyperprolactinaemia. 47 (20 %) were male and 148 (80 % ) were female with mean age 35.4 ± 13.7. 87(47%). Four types of hypofunctioning pituitary gland were seen such as panhypopituitarism, secondray hypogonadism, growth hormone deficiency and central hypothroidism and were associated with more frequent normal MRI. Patients with MRI evidence of microprolactinoma were identified, three (3.4%) of whom had one or more anterior pituitary hormone deficiencies. A total of 98 (53%) patients with MRI-negative idiopathic hyperprolactinaemia were identified, twelve (12.2%) of whom had one or more anterior pituitary hormone deficiencies. Patients in the MRI-positive and MRI-negative groups had panhypopituitarism, hypogonadotrophic hypogonadism and growth hormone deficiency that required hormone. Conclusion: The current study shows an increased frequency anterior pituitary hormone deficiency in patients with idiopathic hyperprolactinaemia, not with pitutary microadenoma. A prospective study would be required to assess the underlying cause for these abnormalities, as they suggest a nontumour pan-pituitary process. Limitations: Question of clustering of cases within the study region and limited study sample size.