Giant Prolactinomas: Report of 6 Cases and Review of Literature

Abstract

Introduction: Giant prolactinomas are rare tumors, representing only 2- 3% of all prolactin (PRL)-secreting tumors. Endocrine symptoms are often present but overlooked for a long period of time. The management of giant prolactinomas remains a major challenge, despite dopamine agonists being the first line of treatment, owing to its efficacy to normalize prolactin levels and reduce tumor volume. Aim of the study: Describe clinical and radiological features, the treatment modalities and outcomes of 6 cases of giant prolactinomas and review of the literature. Methods: Retrospective data collection involving 6 patients diagnosed with giant prolactinoma in the Department of Endocrinology, Hedi Chaker Hospital, Sfax, Tunisia from January 2010 to December 2014. Results: All patients were men between the age of 19 and 65 years. The most common presenting features include headache and visual defects. Proptosis was reported in one patient. Tumor size ranged from 56 to 84 mm and pre-treatment PRL from 1470 to 642387 ng/mL. Endocrine evaluation performed at baseline showed secondary hypogonadism in all patients. Secondary hypothyroidism and adrenal insufficiency were found in one and four patients respectively. IGF-I level was within the normal range for age and gender for all patients. Dopamine agonists served as the primary therapy for all the patients in the present study. Trans-frontal pituitary surgery was performed in one patient with apoplexy and severe neuro-ophthalmic signs. Serum prolactin concentrations and tumor volume significantly decreased following treatment with dopamine agonists. Conclusion: Giant prolactinomas are uncommon and often raising both diagnostic and therapeutic challenges.