ESPE Abstracts

Introduction: Prolactinomas represent 50% of all pediatric pituitary adenomas. Microadenomas (tumors with less than 40 mm in maximum diameter) and giant prolactinomas (more than 40 mm in maximum diameter and prolactin levels > 1000 μg/L) are more commonly found in boys. Giant prolactinomas are rare, but invasive, accounting for 1–5% of prolactin-secreting tumors. We hereby report a female patient with neuro-ophthalmic symptoms (headaches and left 3^rd nerve paralysis) and MRI findings of pituitary macroadenoma.

Case report: A 13-year-old female was admitted for 1 month history of headache and recent unilateral “exophthalmia”. Her medical and family history were unremarkable. The physical exam was normal, with Tanner stage I, and short stature (-2 SD). No spontaneous or provocative galactorrhea. Neurological and visual field examination results were normal. Ophthalmologic exam revealed dilated pupil, ptosis of the upper eyelid, and lateral deviation of the left eye. Biological work-up found no impairment of pituitary secretion, except prolactin level > 200000 mIU/L, with secondary hypogonadism (LH and FSH < 0.3 IU/L). Genetic results are pending. MRI showed a large pituitary mass, measuring 41x35x30 mm, with a tumor volume of 45.5 cm³. There was extension superiorly, anteriorly, with involvement of the cavernous sinuses and left orbit. The optic chiasm was not affected. She was started on medical treatment (cabergoline) and the protocol consisted of a starting dose of 0.5 mg/week, adjusted according to the prolactin response (actual dose 1 mg/week). Her responsiveness (biological and radiological) to treatment was favorable, with slow decrease in prolactin level (table 1), tumor shrinkage, and improvement of the oculomotor paralysis. Side effects of cabergoline were relatively important.

Conclusion: In spite of the initial neuro-ophthalmic picture with invasion of the surrounding structures (cavernous sinus, left orbit), clinical, biological, and MRI evolution of our patient was favorable, with good response to dopamine agonist. Giant prolactiomas can be challenging by their clinical picture (neurological rather than endocrine symptoms), aggressiveness, with invasion of the surrounding structures, but remain benign by their response to medical therapy.