Acromegaly is a chronic disease caused by excessive secretion of growth hormone (GH) and mainly due to benign tumour localized in the pituitary gland. The disease develops insidiously, causing a gradual progression of symptoms; consequently most patients are diagnosed in their fourth decade of life. Administration of somatostatin analogues such as lanreotide have been shown to result in normalisation or the decrease of GH and insulin growth factor (IGF-1) levels and improvement of clinical symptoms in acromegalic patients. The purpose of this study is to evaluate whether lanreotide is also effective on tumour volume reduction (tumour shrinkage) and the benefits of this potential tumour shrinkage on disease symptoms and patient’s quality of life.