Acromegaly

Pure endoscopic transsphenoidal surgery for treatment of acromegaly: results of 67 cases treated in a pituitary center

Object

Acromegaly is a chronic disease related to the excess of growth hormone (GH) and insulin-like growth factor–I secretion, usually by pituitary adenomas. Traditional treatment of acromegaly consists of surgery, drug therapy, and eventually radiotherapy. The introduction of endoscopy as an additional tool for surgical treatment of pituitary adenomas and, therefore, acromegaly represents an important advance of pituitary surgery in the recent years. The aim of this retrospective study is to evaluate the results of pure transsphenoidal endoscopic surgery in a series of patients with acromegaly who were operated on by a pituitary specialist surgeon. The authors discuss the advantages, outcome, complications, and factors related to the success of the endoscopic approach in cases of GHsecreting adenomas.

Methods

The authors retrospectively analyzed data from cases involving patients with GH-secreting adenomas who underwent pure transsphenoidal endoscopic surgery at the Department of Neurosurgery of the General Hospital in Fortaleza, Brazil, between 2000 and 2009. Tumors were classified according to size as micro- or macroadenomas, and tumor extension was analyzed based on suprasellar/parasellar extension and sella floor destruction. All patients were followed up for at least 1 year. The criteria of disease control were GH levels < 1 ng/L after oral glucose tolerance test and normal insulin-like growth factor–I levels for age and sex.

Results

During the study period, 67 patients underwent pure endoscopic transsphenoidal surgery for treatment of acromegaly. Disease control was obtained in 50 cases (74.6%). The rate of treatment success was higher in patients with microadenomas (disease control achieved in 12 [85.7%] of 14 cases) than in those with larger lesions. Suprasellar/parasellar extension and high levels of sella floor erosion were associated with lower rates of disease control (p = 0.01 and p = 0.02, respectively). Complications related to the endoscopic surgery included epistaxis (6.0%), transitory diabetes insipidus (4.5%), and 1 case of seizure (1.5%).

Conclusions

Endoscopic transsphenoidal surgery represents an effective option for treatment of patients with acromegaly. High disease control rates and a small number of complications are some of the most important points related to the technique. Factors related to the success of the endoscopic surgery are lesion size, suprasellar/parasellar extension, and the degree of sella floor erosion. Although presenting important advantages, there is no conclusive evidence that endoscopy is superior to microsurgery in treatment of GH-secreting adenomas.

A case of juvenile acromegaly that was initially diagnosed as severe congestive heart failure from acromegaly-induced dilated cardiomyopathy

Acromegaly is characterized by chronic hypersecretion of growth hormone (GH) and is associated with increased mortality rate because of the potential complications such as cardiovascular disease, respiratory disease, or malignancy, which are probably caused by the long-term exposure of tissues to excess GH, for at least 10 years, before diagnosis and treatment. A 22-year-old man with a 2-month history of fatigue was admitted to our hospital because of chest discomfort, dyspnea, and pitting edema of the lower limbs experienced over a 1-month period. On admission, his height and body weight were 186 cm and 138.5 kg, respectively, with a BMI of 39.8 kg/m(2). He showed acromegalic features and elevated serum GH and IGF-1 levels, which were 11.5 ng/mL and 960 ng/mL, respectively. There was no GH suppression in the 75-g oral glucose tolerance test. Pituitary magnetic resonance imaging (MRI) revealed microadenoma. Chest X-ray revealed cardiomegaly, and echocardiogram showed dilated left ventricular (LV) cavity and diffuse hypokinesis with extremely decreased ejection fraction (EF). He was diagnosed as having acromegaly with congestive heart failure from diastolic cardiomyopathy. After the successful transsphenoidal resection of the pituitary adenoma, the level of GH was normalized. However, the cardiac dysfunction did not show any improvement even after the administration of β-blockers, angiotensin-converting enzyme inhibitor (ACE-I), or diuretics. The patient was re-hospitalized, and he died of cardiac failure at the age of 25 years. Patients with acromegaly have been reported to have about 30% higher mortality rate, and cardiovascular disease accounts for 60% of the deaths. We report a case of a patient with juvenile acromegaly who was diagnosed with severe cardiac failure at the time of diagnosis and failed to recover cardiac function even after the successful resection of the pituitary adenoma. Immediate diagnosis and treatment are required for better control of acromegalic cardiomyopathy.

Inhibition of NFkappaB reduces cellular viability in GH3 pituitary adenoma cells

OBJECTIVE

Adenomas of the pituitary gland are among the most common types of tumors of the adult brain. Although adenomas are histologically benign, they may be associated with significant morbidity and mortality, mostly because of their invasive growth pattern and hormone hypersecretion. Current medical therapies are suppressive, acting at a receptor level. Thus, there is a need to identify novel cellular and molecular targets for pituitary tumors. We investigated the possible role of the NFkappaB transcription factor in pituitary tumor cell growth.

METHODS

The effect of NFkappaB pathway inhibition on cellular viability was studied in the GH3 pituitary adenoma cell line, a well-characterized rat cell line that secretes growth hormone and prolactin. Cells were treated with mechanistically diverse pharmacological NFkappaB pathway inhibitors or with molecular inhibitors that were overexpressed in tumor cells before the assessment of cellular viability. NFkappaB activity was also assessed in GH3 cells using deoxyribonucleic acid binding assays.

RESULTS

GH3 cells exhibited constitutive NFkappaB activity, which contributed to increased cellular proliferation. Treatment with wedelolactone, an IkappaB kinase inhibitor, or overexpression of an IkappaB super-repressor reduced cell viability, further implicating NFkappaB in pituitary tumor cell growth. Pharmacological or molecular inhibition of Akt similarly reduced GH3 viability and NFkappaB binding, suggesting that constitutive activation of NFkappaB may be, at least in part, mediated by Akt.

CONCLUSION

Directed targeting of the Akt and NFkappaB signaling pathways may be a useful adjunct in the clinical management of pituitary tumors. Further elucidation of this pathway may yield novel information regarding the behavior of pituitary tumors in humans.

Outcome of surgical intrasellar growth hormone tumor performed by a pituitary specialist surgeon in a developing country

BACKGROUND

Acromegaly is an excessive GH secretion, which in most cases, is caused by a pituitary GH-secreting adenoma. Traditional treatment of acromegaly consists of surgery, drug therapy, and eventually radiotherapy. The aim of this retrospective study is to evaluate the results of transsphenoidal endoscopic surgery in a group of patients with intrasellar GH adenoma who were operated by a pituitary specialist surgeon. We shall then argue about the economical advantages, for the NHS of a developing country, between surgical and medical treatment.

METHODS

We have analyzed data from 33 patients with intrasellar GH tumor who had been referred to the neuroendocrine department of the HGF, Brazil. The patients underwent a transsphenoidal endoscopic adenomectomy for acromegaly between 2000 and 2005. Their ages were between 20 and 67 years (mean, 44 years) at the moment of surgery. No cavernous sinus invasion was present. Follow-up was a median of 2 years (range, 12 months-6 years).

RESULTS

All 33 patients had intrasellar adenoma, 84.84% of patients achieved remission by surgery. One patient was operated twice and reached hormonal normalization. Five patients still had the disease and refused a second surgery. A treatment with octreotide was started for these 5 patients and resulted in an adequate control of GH and IGF-1 levels. No patients had radiotherapy.

CONCLUSION

Our patients, with intrasellar GH tumor, operated by a pituitary specialist neurosurgeon had remission rates approaching those obtained by most specialized neurosurgical centers worldwide. For equal results, our study shows that the surgical treatment is the best issue for the patient and for the NHS.