Acromegaly caused by growth hormone-releasing hormone-producing tumors: long-term observational studies in three patients

Ectopic acromegaly with tumoral range hyperprolactinemia and apoplexy with a dramatic regression of pituitary hyperplasia

Acromegaly due to ectopic secretion of growth hormone-releasing hormone (GHRH) is a rare disorder. The signs and symptoms of ectopic acromegaly are indistinguishable from acromegaly due to a somatotroph adenoma. A 35-year-old female presented with secondary amenorrhea for 10 years, intermittent headache, and reduced vision in both eyes for 4 years, which worsened over 4 months before presentation. Additionally, she was diagnosed with uncontrolled diabetes mellitus. On examination, she had coarse facial features, a fleshy nose, and acral enlargement. She had diminished visual acuity (left>right) and bitemporal hemianopia on perimetry. Biochemical investigations revealed elevated IGF-1 [588 ng/ml, reference range (RR) 100-242], markedly elevated basal growth hormone (>80 ng/ml; RR, 0.12-9.88), and hyperprolactinemia in the tumoral range (832 ng/ml; RR, 5-25). MRI sella demonstrated a 22×30×34mm sellar-suprasellar mass with T2 hypointensity. Chest imaging revealed a 75×87×106mm left lung mass, which was found to be a well-differentiated neuroendocrine tumor (NET) on biopsy. Plasma GHRH levels were elevated [38,088 ng/l; RR, <250-300], and a diagnosis of ectopic acromegaly secondary to lung neuroendocrine tumor was considered. During workup, the patient developed in-hospital pituitary apoplexy, which improved with medical management. After a left pneumonectomy, her clinical features of acromegaly improved, her diabetes underwent remission, and there was a marked reduction in plasma GHRH and pituitary size. Histopathology was suggestive of a neuroendocrine tumor, with immunohistochemistry positive for GHRH and negative for prolactin. Her final diagnosis was ectopic acromegaly due to GHRH secreting a lung NET with pituitary somatotroph and lactotroph pituitary hyperplasia and apoplexy in the hyperplastic pituitary.

Oral octreotide capsules for acromegaly treatment: application of clinical trial insights to real-world use

INTRODUCTION

Acromegaly is a rare endocrine disorder usually caused by a benign growth hormone‒secreting pituitary adenoma. Surgical adenoma resection is typically the first line of treatment, and medical therapy is used for patients with persistent disease following surgery, for adenoma recurrence, or for patients ineligible for, or declining, surgery. Approved somatostatin receptor ligands (SRLs) have been limited to injectable options, until recently. Oral octreotide capsules (OOC) are the first approved oral SRL for patients with acromegaly.

AREAS COVERED

We review published reports and provide case study examples demonstrating practical considerations on the use of OOC. Using two hypothetical case scenarios, we discuss current treatment patterns, breakthrough symptoms and quality of life (QoL), efficacy of SRLs, OOC dose titration, evaluation of OOC treatment response, and incidence and management of adverse events.

EXPERT OPINION

OOC are an option for patients with acromegaly including those who experience breakthrough symptoms, who have preference for oral therapies, or other reasons for declining injectable SRLs. OOC have been associated with improved patient-reported QoL measures compared with those reported for lanreotide and octreotide. Continued real-world experience will determine whether OOC, alone or in combination with other therapies, provides further advantages over current injectable acromegaly treatments.

Pancreatic GHRHomas in Patients with or without Multiple Endocrine Neoplasia Type 1 (MEN 1) : An Analysis of 36 Reported Cases

Pancreatic GHRHomas (pGHRHomas) with acromegaly have unique conditions, harboring the existence of multiple endocrine neoplasia type 1 (MEN 1). Moreover, pituitary lesions are affected by both protracted ectopic GHRH and loss of menin function. Of significance is the clarification of clinicopathological aspects of pGHRHomas in patients with or without MEN 1. From 1977-2016, thirty-six patients with pGHRHomas were reported. Twenty-two out of 36 patients (61%) had pGHRHomas with MEN 1 and 14 patients did not. The former had a tendency of male predominance, benign tumor behavior and fewer metastasis rather than the latter. The latter is a single pGHRHoma accompanied by pituitary enlargement with somatotroph hyperplasia (hyperplasia) caused by protracted ectopic GHRH. Nine patients with MEN 1 underwent transsphenoidal surgery (TSS). The hyperplasia associated with various pituitary adenomas (PAs) including three GH-related adenomas was observed in seven subjects (32%). In these patients, the resection of their pGHRHomas was feasible. Furthermore, all patients with acromegaly due to pGHRHomas without MEN 1 had non-TSS, whereas approximately 70% of those with MEN 1 had unnecessary TSS. The association with hyperplasia and various PAs suggested that formation of the three GH-related adenomas may be induced by the foundations of MEN 1 gene mutations. J. Med. Invest. 71 : 1-8, February, 2024.

The Surgical Management of Lung Neuroendocrine Neoplasms

This review summarizes key recent developments relevant to the surgical management of lung neuroendocrine neoplasms (L-NENs), including typical and atypical carcinoids, large cell neuroendocrine carcinoma, and small cell lung carcinoma. This review includes recent insights into the classification, clinical presentation, diagnostic workup, treatment options, and follow-up. Highlighted topics include general principles of surgery in localized or locally advanced or metastatic L-NENs, lung-sparing surgery for small, peripheral typical carcinoids, adjuvant and systemic therapies for typical and atypical carcinoids, and surgery and adjuvant therapies for large cell neuroendocrine carcinoma and small cell lung carcinoma.

Ockham's Razor for a Retinal Lesion and Acromegaly and Breaking the Vicious Circle

Acromegaly due to ectopic secretion of growth hormone-releasing hormone (GHRH) is rare. Treatment consists of surgical removal of the primary tumor, cytostatic therapy, "cold" or radioactive somatostatin analogue treatment, and medical therapy for acromegaly, if needed. A 53 year-old female had an ocular lesion noted on a routine optician visit, originally considered to be an ocular melanoma. She had a bronchial carcinoid successfully removed 22 years previously. She had acromegalic features with an enlarged pituitary gland on magnetic resonance imaging and, additionally, metastatic lesions in her bones, liver, and thyroid gland. Elevated GHRH levels (>250× upper limit of normal) suggested a metastatic lung neuroendocrine tumor secreting GHRH. Cold and radioactive somatostatin analogue therapy reduced both GHRH and insulin-like growth factor 1 (IGF-1) levels, but normalization of the biochemical markers of acromegaly was only achieved after pegvisomant was introduced. Complete control of IGF-1 was achieved, and this may have hindered the growth of the metastatic lesions as well, as the patient remains well 13 years after the diagnosis of metastatic disease and 35 years after the original lung operation. A gradual rise in prolactin levels over last 4 years was noted, which is likely due to the prolonged effect of GHRH on prolactin-secreting cells. The diagnosis of this case applied the law of parsimony from the Ockham's razor principle. We consider that breaking the vicious circle of IGF-1 feeding the metastatic tumor was key for the long-term outcome of this case.

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

INTRODUCTION

Ectopic 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.

OBJECTIVES

To determine most common clinical features and diagnostic challenges in ectopic acromegaly.

PATIENTS AND METHODS

A 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.

RESULTS

Neuroendocrine 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.

CONCLUSION

Although 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.

Growth hormone-releasing hormone-secreting pulmonary neuroendocrine tumor associated with pituitary hyperplasia and somatotropinoma

Acromegaly caused by ectopic growth hormone-releasing hormone (GHRH)-secreting tumor is exceedingly rare. We report a case of acromegaly secondary to GHRH secretion by an incidentally diagnosed pulmonary neuroendocrine tumor (NET) and review 47 similar cases in literature. A 22-year-old male patient presented with symptoms of pituitary apoplexy. Magnetic resonance imaging (MRI) showed apoplexy of a pituitary adenoma. Routinely prior to surgery, a chest radiography was performed which revealed a mass in the left lung. During investigation, the patient was diagnosed with metastatic GHRH-secreting pulmonary NET. In retrospect, it was noted that the patient had pituitary hyperplasia 20 months prior to the MRI which showed the presence of a pituitary adenoma. The histological findings confirmed somatotroph hyperplasia adjacent to somatotropinoma. This case suggests that GHRH secretion can be associated with pituitary hyperplasia, which may be followed by pituitary adenoma formation.

Growth hormone-producing pituitary adenomas in childhood and young adulthood: clinical features and outcomes

PURPOSE

Growth hormone (GH)-producing pituitary adenomas (PAs) in childhood or young adulthood are rare, and the details surrounding these tumors remain enigmatic. We present the clinical, pathological and genetic features of this disease.

METHODS

We identified 25 patients aged 20 years or younger with GH-producing PAs who underwent surgery between 2003 and 2016 at Toranomon Hospital in Tokyo. We retrospectively reviewed the clinical data, treatment outcomes and pathological features of these patients to shed light on childhood acromegaly.

RESULTS

The cohort comprised 14 male and 11 female patients whose average age at the time of surgery was 17.3 years. Germline AIP mutations were present in 5 of 13 patients examined, and Carney complex was identified in 2 of 25 patients. The mean maximum tumor diameter was 26.7 mm, and total resection assessed during surgery was achieved in 17 patients. Based on their respective pathological findings, patients were divided into the following 4 groups: sparsely granulated adenomas (5), densely granulated (DG) adenomas (6), plurihormonal adenomas (9), and silent subtype 3 (SS3) adenomas (5). During the mean follow-up period of 50.3 months, complete endocrinological remission was achieved in 14 of 25 patients (56%) by surgery alone and in 19 patients (76%) after postoperative adjuvant therapy.

CONCLUSIONS

GH-producing PAs in young patients are intriguing and difficult to treat due to their distinct tumor characteristics, including a lower incidence of the DG subtype and a higher incidence of SS3 adenomas and genetic abnormalities. Therefore, multi-modal therapies are essential to achieve optimal clinical outcomes.

Paraneoplastic endocrine syndromes

The majority of neoplasms are responsible for symptoms caused by mass effects to surrounding tissues and/or through the development of metastases. However, occasionally neoplasms, with or without endocrine differentiation, acquire the ability to secrete a variety of bioactive substances or induce immune cross-reactivity with the normal tissues that can lead to the development of characteristic clinical syndromes. These syndromes are named endocrine paraneoplastic syndromes when the specific secretory components (hormones, peptides or cytokines) are unrelated to the anticipated tissue or organ of origin. Endocrine paraneoplastic syndromes can complicate the patient's clinical course, response to treatment, impact prognosis and even be confused as metastatic spread. These syndromes can precede, occur concomitantly or present at a later stage of tumour development, and along with the secreted substances constitute the biological 'fingerprint' of the tumour. Their detection can facilitate early diagnosis of the underlying neoplasia, monitor response to treatment and/or detect early recurrences following successful initial management. Although when associated with tumours of low malignant potential they usually do not affect long-term outcome, in cases of highly malignant tumours, endocrine paraneoplastic syndromes are usually associated with poorer survival outcomes. Recent medical advances have not only improved our understanding of paraneoplastic syndrome pathogenesis in general but also enhanced their diagnosis and treatment. Yet, given the rarity of endocrine paraneoplastic syndromes, there is a paucity of prospective clinical trials to guide management. The development of well-designed prospective multicentre trials remains a priority in the field in order to fully characterise these syndromes and provide evidence-based diagnostic and therapeutic protocols.

Acromegaly in a patient with a pulmonary neuroendocrine tumor: case report and review of current literature

Background

Pulmonary neuroendocrine tumors (NET) form a heterogeneous group of rare diseases. In these tumors, paraneoplastic syndromes have been described to drive the course of the disease, among them acromegaly induced by paraneoplastic secretion of growth hormone-releasing hormone (GHRH).

Case presentation

We report the case of a 43 years old patient initially diagnosed with acromegaly accompanied by weight gain and acral enlargement. Subsequently, further diagnostic work-up identified a solitary pulmonary neuroendocrine tumor (NET). Laboratory tests revealed markedly increased growth hormone (GH) and insulin-like growth factor 1 (IGF-1) without GHRH elevation in the absence of pituitary pathologies confirming the paraneoplastic origin of clinical presentation with acromegaly. Curative surgery was performed leading to normalization of the elevated hormone levels and improvement of the clinical symptoms. Immunohistochemically, a typical carcinoid (TC) was seen with low proliferation index and abundant IGF-1 expression.

Conclusions

The association of acromegaly and pulmonary NET has only rarely been reported. We present an individual case of paraneoplastic GH- and IGF-1 secretion in a patient with pulmonary NET. Based on their rarity, the knowledge of paraneoplastic syndromes occurring in patients with pulmonary NET such as acromegaly due to paraneoplastic GH- and IGF-1 secretion is mandatory to adequately diagnose and treat these patients.

Thyrotropin secretion in healthy subjects is robust and independent of age and gender, and only weakly dependent on body mass index

CONTEXT

Studies of the influence of sex, age, and body weight on TSH secretion are not unanimous. Most reports are based on a single TSH measurement; studies using frequent blood sampling are scarce and include a limited number of selected subjects.

OBJECTIVE

The goal was to investigate TSH dynamics in 117 healthy adults.

METHODS

TSH was measured by a sensitive immunofluorometric assay. Secretion parameters were quantified by automated deconvolution, approximate entropy [ApEn], spikiness, and diurnal properties.

RESULTS

Mean age was 43 years (range, 22-77 y). Mean body mass index (BMI) was 26.8 kg/m(2) (range, 18.3-39.4 kg/m(2)). Daily TSH secretion was 45.4 mU/L (range, 8.0-207 mU/L). There were no sex differences in secretion parameters, including pulse frequency; basal, pulsatile, and total secretion; pulse mode; half life; pulse regularity; ApEn; spikiness; and nycthemeral properties. BMI was positively related to basal secretion. Total secretion correlated negatively with free T₄ (R = 0.225; P = .018). The onset of the nocturnal surge was delayed by increasing BMI and advanced by increasing age. ApEn and spikiness correlated positively with age, especially in men. The 9 am sample correlated strongly with the total 24-hour secretion, explaining two-thirds of the variability.

CONCLUSION

This study shows that the 24-hour TSH secretion in healthy volunteers is stable and robust and not influenced by sex, BMI, and age. ApEn in the elderly, especially men, is increased, pointing to a less tight feedback control. Furthermore, aging is associated with advance shifting of the TSH rhythm, which is a phenomenon also observed in other biological rhythms.

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

Background

In 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 presentation

We 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.

Conclusions

This 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.

[Hirsutism and multinodular goiter in a 40-year-old female watchmaker]

This article presents the case of a female patient with acromegaly caused by ectopic production of growth hormone-releasing hormone (GHRH) secretion. In the presence of typical clinical features of acromegaly but a lack of evidence for a pituitary adenoma the results of somatostatin receptor scintigraphy were indicative of a typical carcinoid of the lungs as the cause of the ectopic secretion of GHRH and the stimulation of pituitary gland growth hormone secretion resulting in acromegaly. Finally, the patient underwent curative surgical treatment.

Growth hormone-releasing hormone-producing pancreatic neuroendocrine tumor in a multiple endocrine neoplasia type 1 family with an uncommon phenotype

The objective of this study was to describe a multiple endocrine neoplasia type 1 (MEN1) family characterized by primary hyperparathyroidism, in association with acromegaly because of ectopic growth hormone-releasing hormone (GHRH) secretion by a pancreatic neuroendocrine tumor in a young man and with a bronchial carcinoid in his mother. We investigate the clinical, radiological imaging, histopathologic findings, and therapy. An 18-year-old man successfully underwent subtotal parathyroidectomy for primary hyperparathyroidism. A subsequent genetic analysis showed a MEN1 gene mutation. Three years later, acromegaly because of ectopic GHRH secretion was diagnosed (pituitary MRI negative and elevated GHRH levels). A search for an ectopic tumor was unsuccessful and somatostatin analog therapy was started. Successively, scintigraphy with somatostatin analogs (68-Ga-DOTATOC-PET) showed three focal areas in the pancreatic tail. Distal pancreatectomy showed multiple pancreatic neuroendocrine tumors and hormonal status was normalized. Afterwards, the evaluation of the patient's mother, carrying the same mutation, indicated a primary hyperparathyroidism and a 4 cm lung mass. The patient underwent subtotal pneumonectomy and the histological analysis was consistent with the diagnosis of a typical bronchial carcinoid. In conclusion, an atypical phenotype may be recorded in MEN1 families, thus emphasizing the importance of the new imaging and surgical techniques in the diagnosis and treatment of such a rare disease.

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.

Biochemical markers for gastroenteropancreatic neuroendocrine tumours (GEP-NETs)

Biochemical markers are applied in gastroenteropancreatic neuroendocrine tumours (GEP-NETs) for diagnostic, prognostic or predictive purposes. Chromogranin A is the most important general marker and it is recommended to be measured in every patient with a suspected NET, whereas Neuron Specific Enolase is elevated mainly in poorly differentiated NETs. Pancreatic Polypeptide is used in the diagnosis of pancreatic non-functioning NETs, whereas Chorionic Gonadotrophin has an adjunctive role. In the case of functioning tumours, specific markers should be sought and monitored during follow up. Endogenous hyperinsulinemia is suggested in the presence of non-suppressible insulin and proinsulin levels during hypoglycemia, whereas high fasting or stimulated gastrin levels along with elevated gastric acid output are diagnostic for the Zollinger-Ellison syndrome. Glucagon, vasoactive intestinal polypeptide (VIP) and somatostatin are markers for glucagonoma, VIP-oma and somatostatinoma syndromes respectively. In case of ectopic paraneoplastic syndrome, the relevant hormone serves as a diagnostic and prognostic marker.

Comparison of octreotide LAR and lanreotide autogel as post-operative medical treatment in acromegaly

Long-acting somatostatin analogs are frequently used as adjuvant treatment of acromegaly patients after noncurative surgery. This sudy aims to compare the efficacy of octreotide long-acting release (OCT) and lanreotide Autogel (LAN) in acromegaly patients. Sixty-eight patients not cured by transsphenoidal endoscopic or microscopic pituitary surgery between 2003 and 2009 were retrospectively analyzed (25 men; 43 women; mean age 41.1 ± 10.9 years [range 18-65 years]). The patients were assigned randomly to OCT (n = 36) and LAN (n = 32) groups. Evaluations included insulin-like growth factor I (IGF-I) and growth hormone (GH) after oral glucose tolerance test (OGTT) 3, 6, 12 and 18 months after starting medical treatment; pituitary magnetic resonance imaging was performed before treatment and after 3 and 12 months. Patients achieving IGF-I levels within the age and gender normal range and GH level <1 μg/l following OGTT were considered a 'biochemical cure'. Mean IGF-I and GH values and tumor volumes (cm(3)) in the LAN and OCT groups were similar in the post-operative period before initiation of medical treatment. A statistically significant decrease in GH and IGF-I levels was obtained for both treatment groups at each follow-up visit compared to the previous value. Tumor shrinkage after 12 months of treatment was statistically significant in both groups but the percentage tumor shrinkage (28.5% vs. 34.9%, P = 0.166) and rate of patients achieving biochemical cure (63.9 and 78.1%, P = 0.454) were similar between OCT and LAN groups, respectively. OCT and LAN treatment options have similar efficacy for ensuring biochemical cure and tumor shrinkage in acromegaly patients who had noncurative surgery.

Clinical characteristics and outcome of acromegaly induced by ectopic secretion of growth hormone-releasing hormone (GHRH): a French nationwide series of 21 cases

CONTEXT

Ectopic GHRH secretion is a rare cause of acromegaly, and case reports are mainly isolated.

SETTING

From the registry of the sole laboratory performing plasma GHRH assays in France, we identified cases of ectopic GHRH secretion presenting with acromegaly between 1983 and 2008.

PATIENTS

Twenty-one patients aged 14-77 yr were identified from 12 French hospitals. Median GHRH was 548 (270-9779) ng/liter.

MAIN OUTCOME MEASURES

Outcome measures included description of tumor features and outcome and the relation between plasma GHRH values and tumor site, size, and spread.

RESULTS

The primary neuroendocrine tumor was identified for 20 of 21 patients (12 pancreatic, seven bronchial, one appendicular). Tumors were large (10-80 mm), identified on computed tomography scan in 18 cases and by endoscopic ultrasound and somatostatin receptor scintigraphy in two. Somatostatin receptor scintigraphy had a similar sensitivity to computed tomography scan (81 vs. 86%). Tumors were all well differentiated; 47.6% had metastasized at the time of diagnosis of acromegaly. After a median follow-up of 5 yr, 85% of patients were alive. Ninety-one percent of patients whose tumor was completely removed were considered in remission, and most had normalized plasma GHRH. The remaining patients were treated with somatostatin analogs: IGF-I normalized except for one patient who required pegvisomant, but GHRH levels remained elevated. No correlations were found between GHRH levels and tumor site or size or the existence of metastases. Identification of increased plasma GHRH during follow-up was an accurate indicator of recurrence.

CONCLUSIONS

The prognosis of endocrine tumors responsible for GHRH secretion appears relatively good. Plasma GHRH assay is an accurate tool for diagnosis and follow-up.

Recent results of basic and clinical research in MEN1: opportunities to improve early detection and treatment

Due to the variable expression of multiple endocrine neoplasia type 1 (MEN1), it is difficult to predict the course of the disease. However, knowledge about the normal function of the MEN1 gene product, together with the effects of cellular derangement by subsequent genetic events, has increased considerably. At first, the possible existence of a genotype-phenotype correlation is discussed. Thus, mild- and late-onset phenotypes may be distinguished from more malignant phenotypes depending on the character of the primary MEN1 disease gene mutation. Subsequently, tumor-promoting factors such as gender, additional genetic mutations and ecogenetic factors may contribute to the course of the disease. New developments in management are based on the knowledge and experience of the multidisciplinary teams involved. Finally, the metabolic effects of MEN1 mutations in aged patients are discussed. Early identification of predisposition to the disease, together with knowledge about the natural history of specific mutations, risks of additional mutations and periodic clinical monitoring, allow early treatment and may improve life expectancy and quality of life.

Inhibitory effects of GHRH antagonists on human GH-secreting adenoma tissue

Experimental data indicate that antagonists of growth hormone-releasing hormone (GHRH) could be used clinically in disorders characterized by excessive GHRH/growth hormone (GH) secretion, but direct evidence for the effectiveness of GHRH antagonists on human pituitary tissue is still lacking. In this study, we investigated the inhibitory effect of our GHRH antagonists MZ-4-71 and JV-1-36 and the somatostatin (SST) analog RC-160 on superfused pituitary cells obtained from a human GH-secreting adenoma. Using Western blot analysis and immunohistochemistry, we demonstrated profuse expression of the GHRH receptor and its major splice variant SV1 and an increase in the expression of Gsa protein in the adenoma tissue. Exposure of the tumor cells to exogenous pulses of GHRH induced definite GH responses, causing a 3- to 5-fold elevation of the basal GH level. The antagonists MZ-4-71 and JV-1-36 did not alter basal GH secretion, indicating that the adenoma cells did not secrete GHRH in an autocrine manner. However, both antagonists prevented the stimulatory effect of exogenous GHRH. Similarly to the GHRH antagonists, neither SST-14 nor the SST analog RC-160 had an effect on the basal GH secretion of the tumor cells, but both peptides inhibited the stimulatory effect of exogenous GHRH, with RC-160 being more potent than SST. Our study provides direct evidence for the effectiveness of potent GHRH antagonists such as MZ-4-71 and JV-1-36 on human pituitary GH-secreting adenoma tissue and strongly suggests that these drugs could be used for therapy of GHRH-associated forms of acromegaly, particularly for those patients in whom surgery fails or is not an option.

Duodenal adenocarcinoma with neuroendocrine features in a patient with acromegaly and thyroid papillary adenocarcinoma: a unique combination of endocrine neoplasia

A 67-year-old woman with familial clustering of thyroid papillary adenocarcinoma was diagnosed with acromegaly due to pituitary macroadenoma. She had multiple skin vegetations, but had no parathyroid and pancreas diseases. Before transsphenoidal surgery, she was further diagnosed as having a duodenal tumor and multiple hypervascular liver nodules. Biopsy specimens from the duodenal tumor and liver nodules were diagnosed histologically as moderately differentiated adenocarcinoma. Immunohistochemically, the tumor cells were positive for chromogranin, synaptophysin and somatostatin receptor 2a, suggestive for neuroendocrine features. After surgery, the patient was not in biochemical remission, and octreotide treatment was initiated. The duodenal cancer was treated with chemotherapy (neoadjuvant cisplatin and S-1). After 24 months, the patient's insulin-like growth factor I level had been normalized, and her liver tumors had not progressed macroscopically. This is a rare case of acromegaly associated with multiple endocrine tumors, not being categorized as conventional multiple endocrine neoplasia. Octreotide treatment might have had beneficial effects on our patient's duodenal adenocarcinoma and liver metastases, both directly via SSTR2a and indirectly via GH suppression, thereby contributing to their slow progression.

Ectopic secretion of GHRH by a pancreatic neuroendocrine tumor associated with an empty sella

Acromegaly is usually the result of a pituitary growth hormone cell-adenoma or is more rarely due to ectopic secretion of growth hormone releasing hormone (GHRH).We report the case of a 60-year-old woman with acromegaly due to a GH-RH-secreting pancreatic tumor. Laboratory evaluation confirmed the diagnosis of acromegaly. Magnetic resonance imaging revealed a partial empty sella with no signs of adenoma. Ultrasound sonography performed for abdominal pains showed a calcified large heterogeneous infrahepatic mass. Computed tomography scan discovered a heterogeneous pancreatic head mass with a diameter of 10cm. Measurement of fasting plasma GHRH was performed showing a high concentration of 604ng/L (normal 10-60). We therefore concluded that the acromegaly was caused by ectopic overproduction of GHRH likely due to the pancreatic tumor. The patient underwent a cephalic duodenopancreatectomy. Histology revealed a well-circumscribed tumor with organoid architecture. Immunohistochemistry demonstrated diffuse positivity for chromogranin A, neuronal specific enolase and synaptophysin and negative immunoreactivity for prolactin, GH and serotonin. These features were concordant with a well-differentiated neuroendocrine tumor of the pancreas. Surgical resection of this pancreatic tumor was followed by significant amelioration of acromegalic signs and normalization of GHRH and GH levels.

[Role of somatostatin receptor ligands in the treatment of acromegaly--literature review]

Acromegaly is a rare disease with typical clinical manifestations. Untreated acromegaly carries a 2-4-fold increase in mortality in long-term outcome. The goal of treatment is double, including biochemical control of the disease (normalization of serum IGF1 levels compared to age and gender matched controls, GH levels below 1 ng/ml after oral glucose load, or random GH below 2.5 ng/ml) and control of the tumor mass. The therapeutic modalities currently available for the treatment of acromegaly are: surgery, medical therapy, radiation therapy and their combinations. The cornerstones of medical therapy in acromegaly are the somatostatin receptor ligands due to their effectiveness in controlling GH excess in 60-70 % of patients and their beneficial effects on tumor volume. Somatostatin analogues have an established role as adjuvant therapy after non-curative surgery, and evidence suggests their use as primary treatment for selected patients. The long-term use of somatostatin receptor ligands is safe and they are well tolerated. Future medical therapy consists of pasireotide, a novel, universal somatostatin receptor agonist, and a new class of drugs named dopastatins. The latter so-called chimeric molecules have strong affinity for somatostatin receptors and dopamine-2 receptors, resulting in a more effective blocking of GH secretion, according to preliminary data. The authors of this paper review the current medical therapy of acromegaly, focusing on the role of somatostatin receptor ligands.

Pancreatic endocrine tumors

Pancreatic endocrine tumors have been steadily growing in incidence and prevalence during the last two decades, showing an incidence of 4-5/1,000,000 population. They represent a heterogeneous group with very varying tumor biology and prognosis. About half of the patients present clinical symptoms and syndromes related to substances released from the tumors (Zollinger-Ellison syndrome, insulinoma, glucagonoma, etc) and the other half are so-called nonfunctioning tumors mainly presenting with symptoms such as obstruction, jaundice, bleeding, and abdominal mass. Ten percent to 15% of the pancreatic endocrine tumors are part of an inherited syndrome such as multiple endocrine neoplasia type 1 (MEN-1), von Hippel-Lindau (VHL), neurofibromatosis, or tuberousclerosis. The diagnosis is based on histopathology demonstrating neuroendocrine features such as positive staining for chromogranin A and specific hormones such as gastrin, proinsulin, and glucagon. Moreover, the biochemical diagnosis includes measurement of chromogranins A and B or specific hormones such as gastrin, insulin, glucagon, and vasoactive intestinal polypeptide (VIP) in the circulation. In addition to standard localization procedures, radiology (computed tomography [CT] scan, magnetic resonance imaging [MRI], ultrasound [US]), somatostatin receptor scintigraphy, and most recently positron emission tomography with specific isotopes such as (11)C-5 hydroxytryptamin ((11)C-5-HTP), fluorodopa and (68)Ga-1,4,7,10-tetra-azacyclododecane-N,N',N″,N‴-tetra-acetic acid (DOTA)-octreotate are performed. Surgery is still one of the cornerstones in the management of pancreatic endocrine tumors, but curative surgery is rarely obtained in most cases because of metastatic disease. Debulking and other cytoreductive procedures might facilitate systemic treatment. Cytotoxic drugs, biological agents, such as somatostatin analogs, alpha interferons, mammalian target of rapamycin (mTOR) inhibitors and tyrosine kinase inhibitors are routinely used. Tumor-targeted radioactive treatment is available in many centres in Europe and is effective in patients with tumors that express high content of somatostatin receptors type 2 and 5. In the future, treatment will be based on tumor biology and molecular genetics with the aim of so-called personalized medicine.

Preoperative lanreotide treatment in acromegalic patients with macroadenomas increases short-term postoperative cure rates: a prospective, randomised trial

OBJECTIVE

To investigate whether 4-month preoperative lanreotide treatment would improve the surgical cure rate of newly diagnosed acromegalic patients with macroadenomas.

DESIGN

A prospective, randomised study.

METHODS

After a baseline evaluation, patients were randomly assigned to 4-month preoperative treatment with lanreotide (starting with 30 mg/2 weeks i.m. and increasing to 30 mg/week i.m. at week 8 if mean GH >2.5 microg/l on GH day curves; pretreatment group, Group 1) or to transsphenoidal surgery (direct surgery group, Group 2). Cure was evaluated 4 months postoperatively primarily by fasting IGF1 less than or equal to age-adjusted upper limit of normal.

RESULTS

A pool of 108 patients was randomly divided into two groups. Five patients in each group were lost to follow-up during the study period, so 49 patients in each group were analysed. At baseline, no difference was observed between the two groups. Cure was established in 24 of 49 (49.0%, 95% confidence interval (CI), 35.0-63.0%) pretreated patients (Group 1) versus 9 of 49 (18.4%, 95% CI, 7.6-29.2%) direct surgery patients (Group 2; P=0.001). Surgical morbidity was recorded in 12 patients (12.2%) and was similar in Group 1 and 2 patients (14.3 and 10.2% respectively; P=0.538). The postoperative hospital stay was similar between groups: being 4.5+/-1.6 days in Group 1 vs 4.8+/-1.9 days in Group 2 (P=0.328).

CONCLUSIONS

Pretreatment with lanreotide before transsphenoidal surgery improves surgical cure rates in patients with GH-secreting pituitary macroadenomas. Pretreatment does not affect surgical complications or duration of hospital stay (ClinicalTrials.gov number, NCT00993356).

Multiple endocrine neoplasia type 1

Multiple endocrine neoplasia type 1 (MEN 1) is an autosomal-dominant inherited tumor syndrome characterized by hyperplasia and/or tumors in the parathyroid glands, the pancreatic islets, the anterior pituitary and adrenal glands, as well as neuroendocrine tumors in the thymus, lungs and stomach, and tumors in nonendocrine tissues. In 1997, the responsible MEN1 gene was identified as a tumor-suppressor gene and its product was named menin. In this review, guidelines for early diagnosis, including MEN1 gene mutation analysis, and treatment, including periodic clinical monitoring, have been formulated, enabling improvement of life expectancy and quality of life. Identification of menin-interacting proteins has provided new insights into the function of menin, notably involving regulation of gene transcription related to proliferation and apoptosis, genome stability and DNA repair, and endocrine/metabolic homeostasis. In the near future, target-directed intervention may prevent or delay the onset of MEN 1-related tumors.

Diminished and irregular thyrotropin secretion with preserved diurnal rhythm in patients with active acromegaly

CONTEXT

The hypothalamo-pituitary-thyroid axis in acromegaly may be altered. Previous studies report diminished serum TSH concentrations in patients with active acromegaly and decreased response to TRH. On the other hand, most patients have normal thyroid hormone concentrations.

OBJECTIVE

Our aim was to analyze serum TSH profiles in relation to GH profiles in patients with untreated acromegaly, in order to delineate aberrations in the hypothalamo-pituitary-thyroid system.

INTERVENTION

Twenty-one patients with active acromegaly and matched controls underwent a 24-h, 10-min blood sampling study. GH and TSH data were analyzed with a newly developed automated deconvolution program, approximate entropy, and cosinor regression.

RESULTS

Basal (10.4 +/- 2.0 vs. 13.8 +/- 1.4 mU/liter . 24 h; P = 0.02) and pulsatile (11.4 +/- 1.7 vs. 18.6 +/- 1.6 mU/liter . 24 h; P = 0.002) TSH secretion was decreased in patients. TSH secretory regularity was diminished with loss of pattern synchrony between TSH and GH. Total TSH secretion correlated with TSH increase after TRH (R = 0.75; P = 0.0001), negatively with the log-transformed GH secretion rate (R = -0.52; P = 0.001), but not with adenoma size. The diurnal TSH rhythm was preserved. Total and free T4 concentrations were similar in patients and controls.

CONCLUSION

Basal and pulsatile TSH secretion is decreased in active acromegaly, although T4 levels are unaffected. Diminished TSH secretion is compatible with enhanced restraint by tumoral GH feedback-driven somatostatin outflow, explaining also the reduced regularity of TSH secretion. Unchanged T4 concentrations might reflect decreased sympathetic function in GH excess states, heightening responsiveness of the thyroid gland to TSH.

Ectopic growth hormone-releasing hormone secretion by a neuroendocrine tumor causing acromegaly: long-term follow-up results

Ectopic secretion of growth hormone-releasing-hormone (GHRH) is a rare cause of acromegaly-representing less than 1% of patients. A 25-year-old woman was admitted to the hospital with acromegaly and a 6 x 6 cm infrahepatic mass. Sellar magnetic resonance imaging indicated diffuse pituitary enlargement consistent with hyperplasia. The infrahepatic mass was resected, and the histopathological diagnosis was a well-differentiated invasive neuroendocrine carcinoma of the duodenum with metastases to local lymph nodes. The tumor cells contained cytoplasmic immunoreactivity for GHRH. Because increased IGF-1 concentrations persisted after the operation, the patient was treated with octreotide long-acting repeatable (LAR) injections of 20 mg/month. Growth hormone and IGF-1 levels normalized. After 6 years of surveillance, a left paraaortic mass was detected by uptake of indium 111 octreotide. Surgical exploration revealed metastatic neuroendocrine carcinoma in a 2.5-cm lymph node. Postoperatively, the IGF-1 concentration was mildly elevated. Octreotide LAR therapy is being continued at 10 mg/month. This case suggests that octreotide treatment may have a beneficial effect on disease course and can be maintained for as long as 7 years in a patient with acromegaly due to a GHRH-secreting neuroendocrine carcinoma.

Therapeutic options in the management of acromegaly: focus on lanreotide Autogel

BACKGROUND

In acromegaly, expert surgery is curative in only about 60% of patients. Postoperative radiation therapy is associated with a high incidence of hypopituitarism and its effect on growth hormone (GH) production is slow, so that adjuvant medical treatment becomes of importance in the management of many patients.

OBJECTIVE

To delineate the role of lanreotide in the treatment of acromegaly.

METHODS

Search of Medline, Embase, and Web of Science databases for clinical studies of lanreotide in acromegaly.

RESULTS

Treatment with lanreotide slow release and lanreotide Autogel((R)) normalized GH and insulin-like growth factor-I (IGF-I) concentrations in about 50% of patients. The efficacy of 120 mg lanreotide Autogel((R)) on GH and IGF-I levels was comparable with that of 20 mg octreotide LAR. There were no differences in improvement of cardiac function, decrease in pancreatic beta-cell function, or occurrence of side effects, including cholelithiasis, between octreotide LAR and lanreotide Autogel(R). When postoperative treatment with somatostatin analogs does not result in normalization of serum IGF-I and GH levels after noncurative surgery, pegvisomant alone or in combination with somatostatin analogs can control these levels in a substantial number of patients.