Ectopic Acromegaly Research Articles

Ectopic acromegaly due to bronchial neuroendocrine tumors: the first description in Russia of three clinical cases

Acromegaly is a neuroendocrine disorder caused by excessive production of growth hormone (GH). In the majority of cases the cause of acromegaly is a pituitary tumor producing GH. Cases of ectopic acromegaly are much rarer. Ectopic acromegaly occurs in cases of tumors which produce growth hormone-releasing hormone (GHRH) or extrapituitary tumors which produce GH. The main sources of excessive GHRH production are neuroendocrine tumors (NETs) of the lung or pancreas. Treatment of ectopic acromegaly consists of surgical removal of the source of GHRH hyperproduction and in cases where surgery is not an option, somatostatin analogues, pegvisomant, chemotherapy, immunotherapy or radiation therapy are used.In this article three cases of ectopic acromegaly due to GHRH-producing lung NETs are presented, each of them being notable for a number of features. In the first two cases, clinical symptoms were mild, besides in the second case ectopic acromegaly was accompanied by primary hyperparathyroidism. In the third case ectopic acromegaly was accompanied by pituitary macroadenoma, and after surgical removal of the lung NET remission of acromegaly was not achieved. In all three cases, lung NETs were detected incidentally on radiologic chest screening for other conditions.

Acromegaly Caused by Ectopic Growth Hormone Releasing Hormone Secretion: A Review.

IntroductionEctopic acromegaly is a rare condition caused most frequently by growth hormone releasing hormone (GHRH) secretion from neuroendocrine tumors. The diagnosis is often difficult to establish as its main symptoms do not differ from those of acromegaly of pituitary origin.ObjectivesTo determine most common clinical features and diagnostic challenges in ectopic acromegaly.Patients and MethodsA search for ectopic acromegaly cases available in literature was performed using PubMed, Cochrane, and MEDline database. In this article, 127 cases of ectopic acromegaly described after GHRH isolation in 1982 are comprehensively reviewed, along with a summary of current state of knowledge on its clinical features, diagnostic methods, and treatment modalities. The most important data were compiled and compared in the tables.ResultsNeuroendocrine tumors were confirmed in 119 out of 121 patients with histopathological evaluation, mostly of lung and pancreatic origin. Clinical manifestation comprise symptoms associated with pituitary hyperplasia, such as headache or visual field disturbances, as well as typical signs of acromegaly. Other endocrinopathies may also be present depending on the tumor type. Definitive diagnosis of ectopic acromegaly requires confirmation of GHRH secretion from a tumor using either histopathological methods or GHRH plasma concentration assessment. Hormonal evaluation was available for 84 patients (66%) and histopathological confirmation for 99 cases (78%). Complete tumor resection was the main treatment method for most patients as it is a treatment of choice due to its highest effectiveness. When not feasible, somatostatin receptor ligands (SRL) therapy is the preferred treatment option. Prognosis is relatively favorable for neuroendocrine GHRH-secreting tumors with high survival rate.ConclusionAlthough ectopic acromegaly remains a rare disease, one should be aware of it as a possible differential diagnosis in patients presenting with additional symptoms or those not responding to classic treatment of acromegaly.

Pituitary MRI Features in Acromegaly Resulting From Ectopic GHRH Secretion From a Neuroendocrine Tumor: Analysis of 30 Cases

Ectopic acromegaly is a consequence of rare neuroendocrine tumors (NETs) that secrete GHRH. This abnormal GHRH secretion drives GH and IGF-1 excess, with a clinical presentation similar to classical pituitary acromegaly. Identifying the underlying cause for the GH hypersecretion in the setting of ectopic GHRH excess is, however, essential for proper management both of acromegaly and the NET. Owing to the rarity of NETs, the imaging characteristics of the pituitary in ectopic acromegaly have not been analyzed in depth in a large series. Characterize pituitary magnetic resonance imaging (MRI) features at baseline and after NET treatment in patients with ectopic acromegaly. Multicenter, international, retrospective. Tertiary referral pituitary centers. Thirty ectopic acromegaly patients having GHRH hypersecretion. None. MRI characteristics of pituitary gland, particularly T2-weighted signal. In 30 patients with ectopic GHRH-induced acromegaly, we found that most patients had hyperplastic pituitaries. Hyperplasia was usually moderate but was occasionally subtle, with only small volume increases compared with normal ranges for age and sex. T2-weighted signal was hypointense in most patients, especially in those with hyperplastic pituitaries. After treatment of the NET, pituitary size diminished and T2-weighted signal tended to normalize. This comprehensive study of pituitary MRI characteristics in ectopic acromegaly underlines the utility of performing T2-weighted sequences in the MRI evaluation of patients with acromegaly as an additional tool that can help to establish the correct diagnosis.

GHRH secretion from a pancreatic neuroendocrine tumor causing gigantism in a patient with MEN1.

SummaryA male patient with a germline mutation in MEN1 presented at the age of 18 with classical features of gigantism. Previously, he had undergone resection of an insulin-secreting pancreatic neuroendocrine tumour (pNET) at the age of 10 years and had subtotal parathyroidectomy due to primary hyperparathyroidism at the age of 15 years. He was found to have significantly elevated serum IGF-1, GH, GHRH and calcitonin levels. Pituitary MRI showed an overall bulky gland with a 3 mm hypoechoic area. Abdominal MRI showed a 27 mm mass in the head of the pancreas and a 6 mm lesion in the tail. Lanreotide-Autogel 120 mg/month reduced GHRH by 45% and IGF-1 by 20%. Following pancreaticoduodenectomy, four NETs were identified with positive GHRH and calcitonin staining and Ki-67 index of 2% in the largest lesion. The pancreas tail lesion was not removed. Post-operatively, GHRH and calcitonin levels were undetectable, IGF-1 levels normalised and GH suppressed normally on glucose challenge. Post-operative fasting glucose and HbA1c levels have remained normal at the last check-up. While adolescent-onset cases of GHRH-secreting pNETs have been described, to the best of our knowledge, this is the first reported case of ectopic GHRH in a paediatric setting leading to gigantism in a patient with MEN1. Our case highlights the importance of distinguishing between pituitary and ectopic causes of gigantism, especially in the setting of MEN1, where paediatric somatotroph adenomas causing gigantism are extremely rare.Learning pointsIt is important to diagnose gigantism and its underlying cause (pituitary vs ectopic) early in order to prevent further growth and avoid unnecessary pituitary surgery. The most common primary tumour sites in ectopic acromegaly include the lung (53%) and the pancreas (34%) (1): 76% of patients with a pNET secreting GHRH showed a MEN1 mutation (1).Plasma GHRH testing is readily available in international laboratories and can be a useful diagnostic tool in distinguishing between pituitary acromegaly mediated by GH and ectopic acromegaly mediated by GHRH. Positive GHRH immunostaining in the NET tissue confirms the diagnosis.Distinguishing between pituitary (somatotroph) hyperplasia secondary to ectopic GHRH and pituitary adenoma is difficult and requires specialist neuroradiology input and consideration, especially in the MEN1 setting. It is important to note that the vast majority of GHRH-secreting tumours (lung, pancreas, phaeochromocytoma) are expected to be visible on cross-sectional imaging (median diameter 55 mm) (1). Therefore, we suggest that a chest X-ray and an abdominal ultrasound checking the adrenal glands and the pancreas should be included in the routine work-up of newly diagnosed acromegaly patients.

Diverse Manifestation of Acromegaly With Suspicion of Ectopic GHRH Secretion. Report of Two Cases

Introduction: Acromegaly can rarely be caused by an ectopic production of GH or GHRH by various neoplasms, most commonly neuroendocrine tumors of pancreatic or pulmonary origin. Squamous cell carcinoma of the lung has not been associated with ectopic GHRH secretion yet. The authors present two cases of acromegaly with suspicion of GHRH ectopy. Presentation of the Cases: Case 1. A male born in 1945 presenting with typical morphologic features of acromegaly. Pituitary MRI revealed a cuneatic-shaped, hypointense focal lesion (8x7x6 mm) in the right posterior part of the anterior pituitary lobe, radiologically interpreted as either hyperplasia of the intermediate lobe or atypical adenoma in a normal-sized pituitary. IGF-1 and no suppression of GH secretion after oral glucose load were observed. Furthermore, a polycyclic tumor in the 2nd segment of the right lung with pathological metabolic activity in 18FDG- PET/CT was discovered. Ga68- DOTA TATE PET/CT revealed no pathological accumulation of the tracer. After upper right lobectomy, squamous cell carcinoma, non-keratinizing, G3, with a negative immunohistochemical reaction for GH was confirmed. IHC for GHRH and serum GHRH have been scheduled. After surgery and chemotherapy, no biochemical remission of acromegaly was observed and the pituitary MRI showed stable radiological image of the pituitary tumor, suggesting rather a possible metastasis to the pituitary. Due to unfavorable prognosis, the patient was disqualified from neurosurgical resection of the pituitary tumor. Case 2. a male born in 1948 with typical symptoms of acromegaly, elevation of IGF-1 and no suppression of GH in OGTT. Due to MRI contraindications, only CT of the head was performed- it revealed partially empty sella, compressed pituitary with maximal diameter 3 mm and no focal lesions. Treatment with somatostatin analogue was introduced, however, only partial biochemical control was achieved. Ga68- DOTA TATE PET/CT performed after 8 years showed pathological expression of somatostatin receptors in the pancreatic tail. Abdominal CT confirmed a focal lesion in this location, 14x9 mm, with a strong enhancement after contrast administration, suggesting a neuroendocrine tumor. The patient refused to undergo any invasive procedures and remains treated with SRL. Serum GHRH has been scheduled. Conclusion: The authors report two cases of ectopic acromegaly suspicion, with an ambiguous clinical and radiological presentation. In unclear cases of acromegaly, ectopic production of GHRH should be taken into consideration.

MON-294 T2 MRI Signal Analysis of The Pituitary Gland Is Efficient in the Diagnosis of Acromegaly Due to GHRH Ectopic Secretion

Less than 1% of cases of acromegaly are secondary to ectopic secretion of Growth Hormone Releasing Hormone (GHRH), usually from a neuroendocrine tumor. Symptoms of ectopic acromegaly did not differ from classical acromegaly from pituitary origin. GH and IGF 1 values are in the same range. GHRH measurement only could make the correct diagnosis but is not routinely proposed in acromegaly. MRI of the pituitary gland is considered not very effective in ectopic acromegaly. In the literature (1), different patterns are described: pituitary enlargement (46%), adenoma (30%), empty sella (2%) or normal (20%). But T2MRI signal of the pituitary is never mentioned nor illustrated. Finally, in about 30 % of published cases, pituitary surgery, of course inefficient, was performed.These data enhance the poor contribution of imaging studies in the published cases of ectopic acromegaly.We have been able to obtain and read MRIs and particularly T2WI of 27 acromegalic patients- 20 female, 7 male- due to GHRH hypersecretion from a neuroendocrine tumor –principally bronchial carcinoid and pancreatic NET- which have been published or not. Remarquably, T2 sequences were available in only 27/61 cases we have collected. In all these 27 cases but two, the T2 signal was clearly hypointense if compared with the brain cortex, as it has been described in densely granulomated somatotropinomas (2). In one case with T2 hyperintensity, the pituitary mass presented the same imaging characters as multiple brain metastases from a bronchial carcinoïd. In one case, T2 signal was isointense. In 3 cases, tiny millimetric T2 hyperintense images were disseminated within pituitary hyperplasia. In several cases where pituitary MRI was considered as normal, correlation of the patient’age with pituitary size could make suspect an enlarged gland. In a case labeled empty sella, T2MRI signal of the pituitary remnant was hypointense. When coupling T2 and T1 gadolinium enhanced sequences, no pituitary adenoma was visualized and normal pituitary tissue was never identified along with pituitary hyperplasia.In conclusion, T2 MRI hypointense signal of the pituitary gland is a better hallmark than pituitary hyperplasia for the diagnosis of acromegaly due toGHRH ectopic secretion. Analysis of T2 MR signal in these cases is essential to avoid unnecessary interventions to the pituitary.References1 Ghazi A Endocrine 20132 Potorac J Endocr Relat Cancer 2015

Diagnostic challenges and management of a patient with acromegaly due to ectopic growth hormone-releasing hormone secretion from a bronchial carcinoid tumour.

SummaryA male patient presented at the age of 30 with classic clinical features of acromegaly and was found to have elevated growth hormone levels, not suppressing during an oral glucose tolerance test. His acromegaly was originally considered to be of pituitary origin, based on a CT scan, which was interpreted as showing a pituitary macroadenoma. Despite two trans-sphenoidal surgeries, cranial radiotherapy and periods of treatment with bromocriptine and octreotide, his acromegaly remained active clinically and biochemically. A lung mass was discovered incidentally on a chest X-ray performed as part of a routine pre-assessment for spinal surgery 5 years following the initial presentation. This was confirmed to be a bronchial carcinoid tumour, which was strongly positive for growth hormone-releasing hormone (GHRH) and somatostatin receptor type 2 by immunohistochemistry. The re-examination of the pituitary specimens asserted the diagnosis of pituitary GH hyperplasia. Complete resolution of the patient’s acromegaly was achieved following right lower and middle lobectomy. Seventeen years following the successful resection of the bronchial carcinoid tumour the patient remains under annual endocrine follow-up for monitoring of the hypopituitarism he developed after the original interventions to his pituitary gland, while there has been no evidence of active acromegaly or recurrence of the carcinoid tumour. Ectopic acromegaly is extremely rare, accounting for <1% of all cases of acromegaly. Our case highlights the diagnostic challenges differentiating between ectopic acromegaly and acromegaly of pituitary origin and emphasises the importance of avoiding unnecessary pituitary surgery and radiotherapy. The role of laboratory investigations, imaging and histology as diagnostic tools is discussed.Learning points:Ectopic acromegaly is rare, accounting for less than 1% of all cases of acromegaly.Ectopic acromegaly is almost always due to extra-pituitary GHRH secretion, mainly from neuroendocrine tumours of pancreatic or bronchial origin.Differentiating between acromegaly of pituitary origin and ectopic acromegaly can cause diagnostic challenges due to similarities in clinical presentation and biochemistry.Serum GHRH can be a useful diagnostic tool to diagnose ectopic acromegaly.Pituitary imaging is crucial to differentiate between a pituitary adenoma and pituitary hyperplasia, which is a common finding in ectopic acromegaly.Diagnosing ectopic acromegaly is pivotal to avoid unnecessary interventions to the pituitary and preserve normal pituitary function.

Medical Therapy of Pulmonary Neuroendocrine Neoplasms: Targeted, Symptomatic and Chemotherapy.

Whenever feasible, surgery represents the treatment of choice for pulmonary neuroendocrine neoplasms (NENs). In patients with hypersecreting tumors, wide metastatic spread or those not candidates for a surgical treatment, medical therapies may assure a control of the secretory pattern and slow the rate of tumor growth. No specific trials have been designed so far for pulmonary NENs and the first randomized trial entirely dedicated to thoracic NENs (the LUNA trial) is ongoing. International scientific society guidelines (ESMO and NANETS) and recommendations (ENETS) are therefore necessarily based on expert experience, on the subgroup analysis of large multicenter trials not focused on pulmonary NENs, and on the analysis of small retrospective series. Somatostatin analogs represent the therapy of choice in the presence of associated carcinoid syndrome and ectopic acromegaly and a reasonable first-line in slow-progressing tumors. Due to the low rate of proliferation, platinum-based chemotherapy is generally reserved to rapidly progressing tumors. Temozolomide alone or in association has shown activity in small retrospective series or monocentric trials - larger multicenter trials will better define its efficacy. Everolimus alone or in combination with somatostatin analogs has shown activity in the subgroup analysis of a large multicenter trial (RADIANT II). Many other drugs have shown activity in the preclinical models but, at the moment, no prospective and randomized data are available.

Acromegalia ectópica por carcinoide bronquial

Tumours that cause ectopic acromegaly can do so through the secretion of GH or GHRH. One hundred cases of ectopic acromegaly due to secretion of GHRH have been described. Given the rarity of this pathology, we present a clinical case with the aim of contributing our diagnostic-therapeutic experience and the subsequent follow-up. We present the case of a patient with acromegaloid physical features that had evolved over several years. Concomitantly, he also presented other accompanying symptoms that were suggestive of a possible bronchial origin. Facing the clinical suspicion of acromegaly, we opted to confirm it biochemically and subsequently through image study. A hypophysary origin was ruled out, so we carried out screening for a bronchial neuroendocrine and/or gastrointestinal tumor as they are the most frequent localizations. The treatment of choice was surgical resection.

Ectopic acromegaly due to a GH-secreting pituitary adenoma in the sphenoid sinus: a case report and review of the literature

BackgroundIn more than 98% of cases, acromegaly is due to a GH-secreting pituitary adenoma. The term “ectopic acromegaly” includes neuroendocrine tumors secreting GH releasing hormone (GHRH), usually located in the lungs, thymus and endocrine pancreas. Considerably less frequent are cases of ectopic acromegaly due to GH-secreting tumors located out of the pituitary fossa; except for one isolated case of a well-documented GH-secreting lymphoma, the majority of these lesions are located in the sphenoid sinus.Case presentationWe present the case of a 45 year old woman with acromegaly whose MRI showed an empty sella without evidence of a pituitary adenoma but revealed a large mass within the sphenoid sinus. She underwent transsphenoidal surgery and the excised sphenoid sinus mass, proved to be a GH-secreting adenoma; the sellar floor was intact and no other lesions were found in the pituitary fossa. She required postoperative treatment with somatostatin analogs and cabergoline for clinical and biochemical control.ConclusionsThis case highlights the importance of carefully evaluating the structures surrounding the sellar area when a pituitary adenoma is not found with currently available imaging techniques. The finding of an intact sellar floor and duramater lead us to conclude that the patient’s tumor originated de novo from embryological pituitary remnants. Upon a careful review of the literature and a critical evaluation of our case we found neither clinical nor biochemical features that would distinguish an ectopic from the more common eutopically located somatotrophinoma.

A Case of Ectopic Growth Hormone Releasing Hormone (GHRH) from Pancreatic Neuroendocrine Tumor Resistant to Therapy

Introduction: Ectopic secretion of GHRH is a rare cause of acromegaly. However, its recognition is clinically important because different therapeutic approaches are required. Case Presentation: We present a challenging case of acromegaly secondary to ectopic GHRH secretion from pancreatic neuroendocrine tumor in a 52-year-old female. The patient is treated with different modalities which include pegvisomant in an attempt to control the stimulated GH-axis considering the limited data about its use in treatment of ectopic acromegaly. Conclusion: GHRH-secreting tumor is a rare cause of acromegaly. Surgical resection of the tumor is the therapy of choice whenever possible. However, further studies are warranted for unresectable tumor or resistant cases.

Acromegaly induced by ectopic secretion of GHRH: A review 30 years after GHRH discovery

Ectopic acromegaly is very rare and since the discovery of growth hormone-releasing hormone (GHRH), 30 years ago, only 74 cases have been reported in the literature. Except for a recent French series of 21 cases, most of them were case reports. The present review summarizes the current knowledge on clinical presentation, diagnosis and prognosis. Tumors secreting GHRH are neuroendocrine tumors, usually well differentiated and mainly from pancreatic or bronchial origin. They are usually large and easy to localize using TDM and somatostatin receptor scintigraphy. Clinical presentation is an acromegaly of variable intensity, whose features are similar to that of a somatotropic adenoma. Pituitary may be normal or enlarged at MRI which may be difficult to interpret especially in MEN1 patients where the association of a microprolactinoma to a pancreatic tumor secreting GHRH may be misleading. GHRH plasmatic measurement has an excellent specificity for the diagnosis, using a threshold of 250 to 300ng/L and is a good tool for follow-up of patients after treatment. These tumors have a good overall prognosis, even in metastatic forms which represent 50% of cases. Surgical approach is recommended and, when a complete tumoral resection is feasible, results, in most patients, in long-lasting remission. In such cases, GHRH concentration is normalized and its increase is an accurate indicator of recurrence. In uncured patients, somatostatin analogs control GH secretion but inhibit, only partially, GHRH secretion. MEN1 mutation should be systematically investigated in patients with a pancreatic tumor.

Ectopic acromegaly due to growth hormone releasing hormone

Acromegaly secondary to extra-pituitary tumors secreting growth hormone releasing hormone (GHRH) is rarely encountered. We review the literature on ectopic acromegaly and present the index report of ectopic acromegaly secondary to GHRH secretion from a mediastinal paraganglioma. Clinical and pathological manifestations and therapeutic management of 99 patients with ectopic acromegaly are reviewed. Acromegaly secondary to ectopic GHRH secretion is usually caused by a neuroendocrine tumor in the lung and pancreas. We report an additional cause of ectopic acromegaly from a mediastinal paraganglioma. Diagnostic criteria of ectopic GHRH syndrome include biochemical and pathologic tumoral confirmation of GHRH secretion and expression. Management of ectopic acromegaly consists of surgical resection of the primary tumor and biochemical normalization, with possible adjuvant use of somatostatin analogs. The review demonstrates that there are several tumor types, including paragangliomas which may secrete GHRH, leading to acromegaly. Clinical and laboratory manifestations of the syndrome and challenges in diagnosis and management of these rarely encountered patients require early diagnosis and appropriate treatment to prevent long-term morbidity and mortality with ectopic acromegaly.

Effects of Somatostatin Analogs on a Growth Hormone-Releasing Hormone Secreting Bronchial Carcinoid,in Vivoandin VitroStudies

A 56-yr-old woman presented with acromegaly, a pulmonary mass, and elevated levels of GHRH, GH, and IGF-I. Histological examination revealed a bronchial carcinoid with positive staining for GHRH. Somatostatin analogs (SAs) can play an important role in the treatment of neuroendocrine tumors, dependent on the somatostatin receptor subtype (sst) expression pattern. The sst pattern in bronchial carcinoids and effects of SAs have not been extensively investigated, particularly not for the recently developed universal SA SOM230 (Pasireotide) that has high affinity for sst1, 2, 3, and 5. Our objective was to investigate the in vivo response of a GHRH-producing bronchial carcinoid to octreotide (OCT), its sst-expression profile, and in vitro responses to different SAs, including SOM230. In vivo, 50 microg OCT was administered, and plasma GH and GHRH responses were determined. In vitro, the expression of ssts was analyzed by quantitative PCR. Furthermore, the effects of SOM230 and OCT on GHRH secretion were evaluated in primary cell cultures of the carcinoid tissue. In vivo, OCT administration fully suppressed GH and GHRH levels. In vitro, sst1 mRNA was most abundant, followed by sst2 and sst5. Both SOM230 and OCT inhibited GHRH production dose dependently (SOM230 100 nm vs. control, P = 0.01; OCT 110 nm vs. control, P = 0.05). In this case of a GHRH-producing bronchial carcinoid, we demonstrated that SOM230 was a potent inhibitor of GHRH production in vitro and was at least equally potent compared with OCT. Therefore, SOM230 may be a potential therapeutic agent to control GHRH secretion in ectopic acromegaly.

Acromegaly Caused by Ectopic Growth Hormone: A Rare Manifestation of a Bronchial Carcinoid

Ectopic acromegaly due to growth hormone-releasing hormone secretion by a bronchial carcinoid is rare. We report a case of bronchial carcinoid presenting with acromegaly due to ectopic growth hormone production. The patient was treated successfully with right pneumonectomy.

Ectopic growth hormone-releasing hormone secretion by a metastatic bronchial carcinoid tumor: a case with a non hypophysial intracranial tumor that shrank during long acting octreotide treatment

Ectopic acromegaly represents less than 1% of the reported cases of acromegaly. Although clinical improvement is common after treatment with somatostatin (SMS) analogs, the biochemical response and tumor size of the growth hormone-releasing hormone (GHRH)-producing tumor and its metastases are less predictable. Subject A 36-year-old male was referred because of a 3-year history of acromegaly related symptoms. He had undergone lung surgery in 1987 for a "benign" carcinoid tumor. Endocrine evaluation confirmed acromegaly Plasma IGF-1: 984 ng/ml (63-380), GH: 49.8 ng/ml (<5). MRI showed a large mass in the left cerebellopontine angle and diffuse pituitary hyperplasia. Pulmonary, liver and bone metastases were shown by chest and abdominal CT scans. Ectopic GHRH secretion was suspected. Methods Measurement of circulating GHRH levels by fluorescence immunoassay levels and immunohistochemical study of the primary lung tumor and metastatic tissue with anti-GHRH and anti-somatostatin receptor type 2 (sst2A) antibodies. Results Basal plasma GHRH: 4654 pg/ml (<100). Pathological study of liver and bone biopsy material and lung tissue removed 19 years earlier was consistent with an atypical carcinoid producing GHRH and exhibiting sst2A receptor expression. Treatment with octreotide LAR 20-40 mg q. month resulted in normalization of plasma IGF-1 levels. Circulating GHRH levels decreased dramatically. The size of the left prepontine cistern mass, with SMS receptors shown by a radiolabeled pentetreotide scan, decreased by 80% after 18 months of therapy. Total regression of pituitary enlargement was also observed. No changes were observed in lung and liver metastases. After 24 months of therapy the patient is asymptomatic and living a full and active life.

Ectopic Acromegaly: Localization of the Pituitary Growth Hormone-Releasing Hormone Producing Tumor by In-111 Pentetreotide Scintigraphy and Report of Two Cases

Acromegaly is habitually caused by a pituitary growth hormone (GH)-secreting adenoma, resulting in elevated circulating levels of GH and insulinlike growth factor-1 (IGF-1). Ectopic acromegaly is of very rare occurrence, accounting for less than 1% of clinical acromegaly. This entity is more often than not related to a pancreatic or bronchial GH-releasing hormone (GH-RH) producing neuroendocrine tumor, which is responsible for a nonadenomatous hyperplasia of the pituitary somatotrophic cells. The authors report 2 cases of successful detection of a GH-RH-secreting tumor by In-111 pentetreotide scintigraphy, one in a lung and the other in the pancreas.

Innominate artery transection in the setting of a bovine arch

in the literature that ectopic acromegaly is more often seen in women younger than 40 years. Unfortunately, the neuroendocrine tests cannot differentiate between ectopic GHRH secretion and pituitary adenoma. High GH plasma levels and excessive production of GHRH can be suggestive of ectopic secretion, with the exception of very rare cases of excessive GHRH of hypothalamic origin. The somatostatin receptor scintigraphy could have been an alternative diagnostic tool, but it was not performed in our case. In inoperable cases or incomplete operations, octreotide seems to be effective. Surgical excision of the bronchial carcinoid tumor leads to a rapid decrease of GHRH and to a benign clinical course, as is also mentioned in other reports.

Ectopic acromegaly.

Ectopic acromegaly.

Subcutaneous octreotide treatment of a growth hormone-releasing hormone-secreting bronchial carcinoid: superiority of continuous versus intermittent administration to control hormonal secretion

Diagnosis of ectopic acromegaly was made in a 21-year-old female patient who 3 years before had undergone a right pneumectomy for a disseminated bronchial carcinoid. Plasma growth hormone-releasing hormone (GHRH) concentrations were markedly elevated (6440 ng/l; normal value < 100 ng/l), as were serum GH (187 micrograms/l; normal < 5 micrograms/l) and plasma insulin-like growth factor I (IGF-I) levels (6.7 U/ml; normal < 2 U/ml). Retrospective immunohistochemical examination of the carcinoid tumor was positive for GHRH and the tumoral content of GHRH was 2130 ng/g wet weight. Subcutaneous treatment with octreotide was begun and first resulted in a profound inhibition of GH hypersecretion, normalization of plasma IGF-I and only partial reduction of GHRH concentrations. However, the initial dose of 3 x 100 micrograms had to be increased gradually to 4 x 750 micrograms because of a progressive deterioration of the hormonal control. After 15 months of intermittent therapy, octreotide was administered by continuous sc infusion. This treatment improved compliance, allowed the daily dose of octreotide to be reduced to 1500 micrograms and normalized serum GH levels. A near-normalization of the plasma IGF-I concentrations was also obtained, whereas the suppression of plasma GHRH concentrations remained incomplete. Despite favorable evolution of the endocrine parameters, intramedullar metastases were diagnosed and required radiation therapy. This observation emphasizes the superiority of continuous over intermittent administration of octreotide in the treatment of ectopic acromegaly. It also shows that the somatostatin analog acts more at the pituitary level to inhibit GH secretion than at the site of the neuroendocrine tumor.