Endocrine Abstracts

Key Words: Giant – pituitary adenoma

Introduction & Background: Giant pituitary adenomas are uncommon tumors defined by a tumor diameter ≥ 4 cm. Their prevalence estimated at 6-10% of all pituitary adenomas, whose clinical characteristics and prognosis are not well known. The purpose of this work was to evaluate the prevalence as well as the clinical and evolutionary characteristics of giant pituitary adenomas in our series.

Material and methods: Retrospective descriptive study including 15 patients followed-up for giant pituitary adenoma which tumor diameter was greater than or equal to 4 cm. Data were collected from medical records and analyzed by SPSS-V21 software.

Results: Giant pituitary adenomas represent 16.6% of our series of pituitary adenomas (n=15/90) with a mean age of 44.8±16.5 years (extremes of age of 22 and 69 years), with a clear male predominance and a sex ratio of 4. The clinical presentation was dominated by a decrease in visual acuity associated with headaches in 73.3% of cases, associated with cranial nerve damage (III, VI) in 20% and pituitary apoplexy in 13.3% followed by acrogigantism in one case. The hypothalamohypophyseal MRI showed a giant pituitary macroadenoma with a mean diameter of 5.34 cm (with extremes of 4 and 8.2 cm) and a mean volume of 47.9 ±45.5 cm 3. Invasion of the cavernous sinus was observed in 46.6% of the cases and reaching the contact of the internal carotid artery in 40% of the cases, with invasion of the chiasma and optic pathways in 93%. It was a pituitary prolactin adenoma in the most of cases (53,3%) cases followed by non functional pituitary adenoma. Twenty-four percent of the patients benefited from transphenoidal surgical treatment with an indication for revision surgery in 46% of cases. 13.4% of the cases benefited from radiotherapy as a complement to pituitary surgery and 60% were put on dopaminergic analogues and 13.3% on somatostatin analogue. The Ki67 of the operated patients was 4% in one patient with somatotropic adenoma, 2% in one case with prolactin adenoma and 1% in 4 cases.

Discussion-Conclusion: Giant pituitary adenomas, although uncommon, represent a challenge in clinical endocrinology because their prognosis is uncertain requiring multidisciplinary management in diagnosis, therapeutic management and long-term follow-up.