Pituitary tumor disappearance in a patient with newly diagnosed acromegaly primarily treated with octreotide LAR

We describe the case of an acromegalic patient primarily treated with octreotide LAR in whom the pituitary tumor disappeared after 18 months of treatment. A 68-yr-old woman, with clinical suspicion of acromegaly, was admitted to our Unit with the ultrasonographical evidence of cardiac hypertrophy, arrhythmias, right branch block and interatrial septum aneurism. She referred hands and feet enlargement since the age of 30 and facial disfigurements since the age of 50. At the age of 45 she underwent surgery for carpal tunnel syndrome and at the age of 61 an euthyroid nodular goiter was diagnosed. Hormonal evaluation showed elevated circulating GH levels (25±3.2 ng/ml), not suppressible after oral glucose load, and elevated IGF-I levels (646 ng/ml), whereas the remaining pituitary function was normal. Visual perimetry was normal, whereas magnetic resonance imaging (MRI) showed an intrasellar pituitary adenoma with maximal diameter of 9 mm. In order to improve cardiovascular function before surgery, the patient started octreotide LAR 20 mg every 4 weeks for 3 months. Then based on IGF-I values, the dose was adjusted to 30 mg. After 6 months a second MRI showed significant tumor reduction (>50% of baseline maximal diameter), GH and IGF-I were within the normal range and the patient continued the treatment. After one-year therapy, an improvement of cardiac alterations was recorded and the patient was referred to the neurosurgeon. However, she refused the operation. At 18-month follow-up, MRI showed the complete disappearance of direct and indirect signs of pituitary adenoma. To our knowledge, this is the first case of complete radiological remission of pituitary tumor during octreotide LAR treatment in acromegaly.