Endocrine Abstracts

Introduction: Giant pituitary adenomas are defined as tumors with largest diameter ≥40 mm. They are characterized by high invasiveness causing compression of adjacent structures and hormonal dysfunction. The aim of this study was to determine the clinical and paraclinical features, management, and outcome of giant pituitary adenomas.

Methods: This was a single-center retrospective study including patients with giant pituitary adenoma. Clinical and paraclinical data were collected from the medical records.

Results: Twenty patients (14 men and 6 women) were included in this study. Their mean age at diagnosis was 34.8±11.9 years. Giant adenoma was revealed by a tumor syndrome in 17 patients and by signs of hypersecretion in two patients. It was incidentally discovered in one patient. The presenting manifestations were headaches (18 cases), visual disturbances (18 cases), hypogonadism (9 cases), signs of corticotrope deficiency (9 cases), and polyuria-polydipsia syndrome (1 case). The diagnosis of macroprolactinoma was established in 18 patients with a median baseline prolactin level of 8495 ng/ml. Two patients had non-secreting pituitary adenoma. Hypopituitarism was diagnosed in 9 patients. The mean adenoma size was 53.3±9.4 mm (range: 40–77 mm). Optic chiasm compression, cavernous sinus invasion, sphenoid sinus invasion, and hydrocephalus were observed in 14, 15, 11 and 10 patients, respectively. All patients with macroprolactinoma were treated with dopamine agonists (bromocriptine in 6 patients and cabergoline in 12 patients). Transsphenoidal surgery was performed to two patients and two patients required radiotherapy. Full recovery was obtained in only one patient. For the remaining patients, the outcome was marked by a decrease in the adenoma size in six patients.

Conclusion: Giant pituitary adenomas, although not very common, are a therapeutic challenge due to their size, invasiveness, and the fact that they often have extrasellar extensions.