CASE REPORT Complete disappearance of a GH-secreting pituitary macroadenoma in a patient with acromegaly: effect of treatment with lanreotide Autogel and consequence of treatment withdrawal Renata S Auriemma, Mariano Galdiero, Ludovica F S Grasso, Pasquale Vitale, Alessia Cozzolino, Gaetano Lombardi, Annamaria Colao and Rosario Pivonello Department of Clinical and Molecular Endocrinology and Oncology, ‘Federico II’ University of Naples, Via S. Pansini 5, 80131 Naples, Italy (Correspondence should be addressed to R Pivonello; Email: rpivone@tin.it) Abstract Background: Somatostatin analogs (SA) are the cornerstone in the medical treatment of acromegaly, used as either primary or adjunctive therapy. In particular, SA are effective in inducing the biochemical remission of the disease and tumor shrinkage, although only few cases of complete disappearance of the pituitary tumor in patients treated with SA as long-acting formulations have been reported. SA withdrawal has been demonstrated to keep safe levels of GH and IGF1 at least in a small subset of patients well responsive to SA, although it is generally followed by disease recurrence after several months. Case report: A 61-year-old female patient bearing a very large GH-secreting pituitary macroadenoma was treated with 12-month lanreotide Autogel (ATG), at the initial dose of 120 mg/28 days. After 3 months, GH and IGF1 levels were fully normalized, to prolong the administration interval from 28 to 56 days. After 6 months of treatment, a significant tumor shrinkage (90% of baseline size) was observed, whereas GH and IGF1 excess was still well controlled. After 12-month therapy, a complete disappearance of the pituitary tumor was observed, and the hormonal evaluation confirmed the complete biochemical remission of acromegaly. Lanreotide ATG treatment was withdrawn. The clinical, biochemical, and radiological remission of acromegaly was maintained 24 months after lanreotide ATG treatment discontinuation, without evidence of disease recurrence. Conclusions: This report represents an exemplary case of the potentiality of treatment with lanreotide ATG in inducing a complete remission of acromegalic disease, persistent after a long period of time from treatment withdrawal. European Journal of Endocrinology 162 993–999 Introduction Acromegaly is a rare and severe systemic disease caused by a GH-secreting pituitary adenoma, inducing GH and insulin-like growth factor 1 (IGF1) excess (1). Currently available therapies for acromegaly include transsphe- noidal neurosurgery, radiotherapy, and medical therapy with the dopamine agonists and somatostatin analogs (SA). A new engineered GH receptor antagonist, pegvisomant, has recently been shown to be effective in normalizing IGF1 excess in the great majority of patients, including those who have demonstrated resistance to SA (2). The goal of these therapies is to normalize GH and IGF1 levels, to improve the clinical signs and symptoms of acromegaly, and to reduce tumor size in order to relieve any symptom due to tumor mass (3). SA, both octreotide and lanreotide, have been demonstrated to be the cornerstone of medical treat- ment during the last 15 years with their acceptability, increased by the development of depot preparations. SA improve symptoms and signs of acromegaly in the majority of patients, induce the achievement of biochemical targets for both GH and IGF1 levels in 44–77% of patients, and induce tumor shrinkage in at least 41.5% of patients (4–8). Particularly, the long- acting SA lanreotide has been found to be well tolerated and effective in reducing GH and IGF1 levels as well as the tumor mass in a high percentage of patients pre- viously either untreated or treated by unsuccessful neurosurgery for acromegaly (7–27). Only three cases of total biochemical and/or radiological remission of a GH-secreting pituitary adenoma after medical therapy with long-acting SA have been reported (28–30). Moreover, few data on the effects of SA therapy discontinuation on disease control are presently available, and the majority of the authors reported the disease recurrence during a short follow-up. In a recent multicenter study, Ronchi et al. (10) reported the European Journal of Endocrinology (2010) 162 993–999 ISSN 0804-4643 q 2010 European Society of Endocrinology DOI: 10.1530/EJE-09-0769 Online version via www.eje-online.org Downloaded from Bioscientifica.com at 10/03/2021 12:49:45PM via free access