Gigantism

Tall stature and gigantism in transition age: clinical and genetic aspects-a literature review and recommendations

PURPOSE

Tall stature is defined as height greater than the threshold of more than 2 standard deviations above the average population height for age, sex, and ethnicity. Many studies have described the main aspects of this condition during puberty, but an analysis of the characteristics that the physician should consider in the differential diagnosis of gigantism-tall stature secondary to a pituitary tumour-during the transition age (15-25 years) is still lacking.

METHODS

A comprehensive search of English-language original articles was conducted in the MEDLINE database (December 2021-March 2022). We selected all studies regarding epidemiology, genetic aspects, and the diagnosis of tall stature and gigantism during the transition age.

RESULTS

Generally, referrals for tall stature are not as frequent as expected because most cases are familial and are usually unreported by parents and patients to endocrinologists. For this reason, lacking such experience of tall stature, familiarity with many rarer overgrowth syndromes is essential. In the transition age, it is important but challenging to distinguish adolescents with high constitutional stature from those with gigantism. Pituitary gigantism is a rare disease in the transition age, but its systemic complications are very relevant for future health. Endocrine evaluation is crucial for identifying conditions that require hormonal treatment so that they can be treated early to improve the quality of life and prevent comorbidities of individual patient in this age range.

CONCLUSION

The aim of our review is to provide a practical clinical approach to recognise adolescents, potentially affected by gigantism, as early as possible.

Gigantism: microsurgical treatment by transsphenoidal approach and prognostic factors

PURPOSE

We present the results of transsphenoidal microsurgical treatment in 14 patients with gigantism. The influence on the prognosis of factors such as the tumor size and preoperative levels of GH and IGF-1 is also quantified.

MATERIALS AND METHODS

The patients, operated between 1982 and 2004, were reviewed retrospectively in June 2022. All patients had complete endocrinological studies in the preoperative period and a postoperative control between 6 days and 3 weeks. Follow-up has been supported with annual check-ups between 3 and 31 years. We have compared the preoperative levels of GH and IGF-1 of these patients with the levels of a series of acromegalic patients operated on in the same Center.

RESULTS

In this series there were 4 women and 10 men. The age ranged between 14 and 21 years. In 6 patients, postoperative hormone levels achieved the disease control criteria (42.8%). The CT/MRI studies revealed the existence of invasive tumors in 10 of the patients (71.4%). Postoperative CT/MRI showed no tumor tissue in 3 patients but in 7 patients there were tumor remains. The remaining 4 patients had abnormal images although not considered as tumor. A statistical comparison of preoperative serum GH and IGF-1 levels in patients with gigantism and patients with acromegaly showed a significant elevation in the former.

CONCLUSION

Pituitary adenomas that cause gigantism are generally large and invasive, which makes them difficult to cure. High preoperative levels of GH and IGF-1 are also factors that decrease remission.

The Internal Cranial Anatomy of a Female With Endocrine Disorders From a Mediaeval Population

Gigantism and acromegaly have been observed in past populations; however, analyses usually focus on the morphological features of the post-cranial skeleton. The aim of this study is to characterize the internal anatomical features of the skull (brain endocast anatomy and asymmetry, frontal pneumatization, cranial thickness, sella turcica size) of an adult individual from the 11-14th centuries with these two diseases, in comparison with non-pathological individuals from the same population. The material consisted of 33 adult skulls from a mediaeval population, one of them belonging to an adult female with endocrine disorders (OL-23/77). Based on the CT scans, the internal cranial anatomy was analysed. The sella turcica of OL-23/77 is much larger than in the comparative sample. The endocast of the individual OL-23/77 shows a left frontal/left occipital petalia, while the comparative population mostly had right frontal/left occipital petalias. The asymmetry in petalia location in OL-23/77 comes within the range of variation observed in the comparative population. The individual has high values for cranial thickness. The frontal sinuses of the specimen analysed are similar in size and shape to the comparative sample only for data scaled to the skull length. Enlarged sella turcica is typical for individuals with acromegaly/gigantism. The pattern of the left frontal/left occipital petalia in the specimen OL-23/77 is quite rare. The position of the endocranial petalias has not influenced the degree of asymmetry in the specimen. Despite the large bone thickness values, skull of OL-23/77 does not show any abnormal features. The skull/endocast relationship in this individual shows some peculiarities in relation to its large size, while other internal anatomical features are within the normal range of variation of the comparative sample.

MACRODONTIA: A brief overview and a case report of KBG syndrome

Macrodontia is a dental condition where a tooth or group of teeth are abnormally larger than average. Functional and aesthetic discrepancies may arise in affected individuals resulting in lowering the quality of life. It has been noted that macrodontia is associated with several genetic and endocrine abnormalities. Among which, KBG syndrome is a rare genetic disorder characterized by developmental and dental abnormalities. This case report provides a brief overview of the significance of macrodontia, along with presenting a case of KBG syndrome with atypical features in a South African, 16-year-old female. The dental manifestations are often overshadowed by other more conspicuous and complex syndromic features. Recognition of both the clinical and oral changes that occur in KBG syndrome facilitates accurate diagnosis and appropriate management of this condition. The authors highlight the importance for clinicians to be cognizant of the clinical implications of macrodontia.

The intriguing giant deer from the Bate cave (Crete): could paleohistological evidence question its taxonomy and nomenclature?

The research describes for the first time a possible case of pituitary gigantism in fossil mammals, precisely in deer. The pathology was detected in 2 long bones (tibia and metatarsus) belonging to an individual of an unusual large size found at the Bate cave (Rethymnon, Northern Crete). It formed the basis of Candiacervus major, the largest among the endemic deer species recorded in the Pleistocene-Early Holocene of Crete. Radiological and histomorphological examinations highlighted a reduction in cortical bone thickness and the presence of wide lacunae inside of the bone tissue. The pathological conditions suggest a pituitary gigantism diagnosis also supported by some morphological evidence, such as the extremely elongated distal part of the metatarsal diaphysis, the proportionally small proximal epiphysis, and some bone gracility. The diagnosis of a case of pituitary gigantism as presumed responsible for the extraordinary elongation of the tibia and the metatarsal bone is intriguing as they are, respectively, the paratype and the holotype of the C. major. The species represents a case of a deviation from the "island rule" in Pleistocene large mammals. The new evidence recommends a taxonomic and nomenclatural revision of this species. The main outcomes of this research are as follows: (i) a case of pituitary gigantism is described for the first time in an extinct mammal; (ii) it is underlined that paleohistology may provide interesting clues for disentangling taxonomic and nomenclatural issues; (iii) one of the very few cases of gigantism in insular mammals is being questioned.

A legendary sumo wrestler with gigantism or acromegaly? The case of Ikezuki Geitazaemon (1827-1850)

Sumo is a traditional Japanese full-contact wrestling sport. Among sumo wrestlers, Ikezuki Geitazaemon (1827-1850) was one of the most famous wrestlers due to his large body size. Here, we hypothesize that the legendary Japanese sumo wrestler could have had gigantism or acromegaly, which are disorders caused by the hypersecretion of growth hormone (GH). GH-secreting pituitary adenoma leads to the hypersecretion of GH and insulin-like growth factor-1 (IGF-1). If GH-secreting pituitary adenoma develops during childhood/puberty, it can cause gigantism. Adenomas also occur in over 95% of patients with acromegaly. Based on his substantial height (227 cm), Geitazaemon may have had gigantism, or acromegaly considering his characteristics of mandibular prognathism, enlarged fingertips, and heel pad thickness, as shown in woodblock prints (ukiyo-e). He would thus be the first recorded patient with gigantism or acromegaly in premodern Japan.

Pituitary gigantism: a rare learning opportunity

INTRODUCTION

Pituitary gigantism is a rare but significant paediatric condition with complexities surrounding diagnosis and management. Transsphenoidal surgery (TSS) is the treatment of choice; however, medical treatment is often considered as adjuvant therapy.

CASE

A 10½ -year-old boy presented with tall stature and a height velocity of 11 cm/year. His height was 178.7 cm (+5.8 SD above mean) and insulin-like growth factor-1 (IGF-1) was elevated. An oral glucose tolerance test demonstrated non-suppression of growth hormone (GH). Initial contrast MRI was inconclusive, but C-11 methionine functional positron emission tomography CT identified a 6 mm pituitary microadenoma. A multidisciplinary team clinic held with the family allowed discussion about medical and surgical treatment options. Due to a number of factors including the patient's young age, prepubertal status, a wish to allow him to settle into his new high school and his desire to reach a final height taller than his father's height, it was decided to try medical therapy first with a somatostatin analogue. Pubertal induction was also commenced and bilateral epiphysiodesis surgery performed. Initial response to octreotide was positive; however, 4 months into therapy his IGF-1 was climbing and a repeat GH profile was not fully suppressed. The patient therefore proceeded to have successful TSS excision of the adenoma.

CONCLUSION

Rare cases such as this require sharing of knowledge and expertise, so the best possible care is offered. It is often necessary to work across sites and disciplines. Each case requires an individual approach tailored to the patient and their family.

Inferring Relevant Cell Types for Complex Traits by Using Single-Cell Gene Expression

Previous studies have prioritized trait-relevant cell types by looking for an enrichment of genome-wide association study (GWAS) signal within functional regions. However, these studies are limited in cell resolution by the lack of functional annotations from difficult-to-characterize or rare cell populations. Measurement of single-cell gene expression has become a popular method for characterizing novel cell types, and yet limited work has linked single-cell RNA sequencing (RNA-seq) to phenotypes of interest. To address this deficiency, we present RolyPoly, a regression-based polygenic model that can prioritize trait-relevant cell types and genes from GWAS summary statistics and gene expression data. RolyPoly is designed to use expression data from either bulk tissue or single-cell RNA-seq. In this study, we demonstrated RolyPoly's accuracy through simulation and validated previously known tissue-trait associations. We discovered a significant association between microglia and late-onset Alzheimer disease and an association between schizophrenia and oligodendrocytes and replicating fetal cortical cells. Additionally, RolyPoly computes a trait-relevance score for each gene to reflect the importance of expression specific to a cell type. We found that differentially expressed genes in the prefrontal cortex of individuals with Alzheimer disease were significantly enriched with genes ranked highly by RolyPoly gene scores. Overall, our method represents a powerful framework for understanding the effect of common variants on cell types contributing to complex traits.

Skin manifestations of growth hormone-induced diseases

The human skin is a well-organized organ bearing different types of cells in a well-structured interference to each other including epidermal and follicular keratinocytes, sebocytes, melanocytes, dermal papilla cells and fibroblasts, endothelial cells, sweat gland cells as well as nerves. Several hormones act on different cell types of the skin, while it is also considered an endocrine organ secreting hormones that act at several sites of the organism. GH receptors are found in almost all cell types forming the skin, while IGF-1 receptors' expression is restricted to the epidermal keratinocytes. Both Growth Hormone (GH) excess, as in the case of Acromegaly in adults, or Gigantism in growing children, and GH deficiency states lead to skin manifestations. In case of GH excess the main dermatological findings are skin thickening, coarsening of facial features, acrochordons, puffy hands and feet, oily skin and hyperhidrosis, while GH deficiency, on the contrary, is characterized by thin, dry skin and disorder of normal sweating. Moreover, special disorders associated with GH excess may have specific characteristics, as is the case of café-au-lait spots in Neurofibromatosis, or big café-au-lait skin hyperpigmented regions with irregular margins, as is the case in McCune-Albright syndrome. Meticulous examination of the skin may therefore contribute to the final diagnosis in cases of GH-induced disorders.

Clinical importance of achieving biochemical control with medical therapy in adult patients with acromegaly

In acromegaly, achieving biochemical control (growth hormone [GH] level <1.0 ng/mL and age- and sex-normalized levels of insulin-like growth factor 1 [IGF-1]) through timely diagnosis and appropriate treatment provides an opportunity to improve patient outcomes. Diagnosis of acromegaly is challenging because it is rooted in observing subtle clinical manifestations, and it is typical for acromegaly to evolve for up to 10 years before it is recognized. This results in chronic exposure to elevated levels of GH and IGF-1 and delay in patients receiving appropriate treatment, which consequently increases mortality risk. In this review, the clinical impact of elevated GH and IGF-1 levels, the effectiveness of current therapies, and the potential role of novel treatments for acromegaly will be discussed. Clinical burden of acromegaly and benefits associated with management of GH and IGF-1 levels will be reviewed. Major treatment paradigms in acromegaly include surgery, medical therapy, and radiotherapy. With medical therapies, such as somatostatin analogs, dopamine agonists, and GH receptor antagonists, a substantial proportion of patients achieve reduced GH and normalized IGF-1 levels. In addition, signs and symptoms, quality of life, and comorbidities have also been reported to improve to varying degrees in patients who achieve biochemical control. Currently, there are several innovative therapies in development to improve patient outcomes, patient use, and access. Timely biochemical control of acromegaly ensures that the patient can ultimately improve morbidity and mortality from this disease and its extensive consequences.

Burden of Growth Hormone Deficiency and Excess in Children

Longitudinal growth results from multifactorial and complex processes that take place in the context of different genetic traits and environmental influences. Thus, in view of the difficulties in comprehension of the physiological mechanisms involved in the achievement of normal height, our ability to make a definitive diagnosis of GH impairment still remains limited. There is a myriad of controversial aspects in relation to GH deficiency, mainly related to diagnostic controversies and advances in molecular biology. This might explain the diversity in therapeutic responses and may also serve as a rationale for new "nonclassical" treatment indications for GH. It is necessary to acquire more effective tools to reach an adequate evaluation, particularly while considering the long-term implications of a correct diagnosis, the cost, and safety of treatments. On the other hand, overgrowth constitutes a heterogeneous group of different pathophysiological situations including excessive somatic and visceral growth. There are overlaps in clinical and molecular features among overgrowth syndromes, which constitute the real burden for an accurate diagnosis. In conclusion, both GH deficiency and overgrowth are a great dilemma, still not completely solved. In this chapter, we review the most burdensome aspects related to short stature, GH deficiency, and excess in children, avoiding any details about well-known issues that have been extensively discussed in the literature.

Clinical and genetic characterization of pituitary gigantism: an international collaborative study in 208 patients

Despite being a classical growth disorder, pituitary gigantism has not been studied previously in a standardized way. We performed a retrospective, multicenter, international study to characterize a large series of pituitary gigantism patients. We included 208 patients (163 males; 78.4%) with growth hormone excess and a current/previous abnormal growth velocity for age or final height >2 s.d. above country normal means. The median onset of rapid growth was 13 years and occurred significantly earlier in females than in males; pituitary adenomas were diagnosed earlier in females than males (15.8 vs 21.5 years respectively). Adenomas were ≥10 mm (i.e., macroadenomas) in 84%, of which extrasellar extension occurred in 77% and invasion in 54%. GH/IGF1 control was achieved in 39% during long-term follow-up. Final height was greater in younger onset patients, with larger tumors and higher GH levels. Later disease control was associated with a greater difference from mid-parental height (r=0.23, P=0.02). AIP mutations occurred in 29%; microduplication at Xq26.3 - X-linked acrogigantism (X-LAG) - occurred in two familial isolated pituitary adenoma kindreds and in ten sporadic patients. Tumor size was not different in X-LAG, AIP mutated and genetically negative patient groups. AIP-mutated and X-LAG patients were significantly younger at onset and diagnosis, but disease control was worse in genetically negative cases. Pituitary gigantism patients are characterized by male predominance and large tumors that are difficult to control. Treatment delay increases final height and symptom burden. AIP mutations and X-LAG explain many cases, but no genetic etiology is seen in >50% of cases.

X-linked acrogigantism syndrome: clinical profile and therapeutic responses

X-linked acrogigantism (X-LAG) is a new syndrome of pituitary gigantism, caused by microduplications on chromosome Xq26.3, encompassing the gene GPR101, which is highly upregulated in pituitary tumors. We conducted this study to explore the clinical, radiological, and hormonal phenotype and responses to therapy in patients with X-LAG syndrome. The study included 18 patients (13 sporadic) with X-LAG and microduplication of chromosome Xq26.3. All sporadic cases had unique duplications and the inheritance pattern in two families was dominant, with all Xq26.3 duplication carriers being affected. Patients began to grow rapidly as early as 2-3 months of age (median 12 months). At diagnosis (median delay 27 months), patients had a median height and weight standard deviation scores (SDS) of >+3.9 SDS. Apart from the increased overall body size, the children had acromegalic symptoms including acral enlargement and facial coarsening. More than a third of cases had increased appetite. Patients had marked hypersecretion of GH/IGF1 and usually prolactin, due to a pituitary macroadenoma or hyperplasia. Primary neurosurgical control was achieved with extensive anterior pituitary resection, but postoperative hypopituitarism was frequent. Control with somatostatin analogs was not readily achieved despite moderate to high levels of expression of somatostatin receptor subtype-2 in tumor tissue. Postoperative use of adjuvant pegvisomant resulted in control of IGF1 in all five cases where it was employed. X-LAG is a new infant-onset gigantism syndrome that has a severe clinical phenotype leading to challenging disease management.

PITUITARY GIGANTISM--EXPERIENCE OF A SINGLE CENTER FROM WESTERN INDIA

OBJECTIVE

Limited data are available on pituitary gigantism, as it is a rare disorder. This study was carried out to assess the clinical, hormonal, and radiologic profiles and management outcomes of patients with pituitary gigantism.

METHODS

We conduced a retrospective analysis of 14 patients with pituitary gigantism who presented to a single tertiary care institute from 1990 to 2014.

RESULTS

Thirteen patients were male, and 1 was female. The mean age at diagnosis was 21.9 ± 6.1 years, with a mean lag period of 6.5 ± 5.6 years. The mean height SD score at the time of diagnosis was 3.2 ± 0.6. Symptoms of tumor mass effect were the chief presenting complaint in the majority (50%) of patients, while 2 patients were asymptomatic. Six patients had hyperprolactinemia. At presentation, the nadir PGGH (postglucose GH) and insulin-like growth factor (IGF 1)-ULN (× upper limit of normal) were 63.2 ± 94.9 ng/mL and 1.98 ± 0.5, respectively. All (except 1 with mild pituitary hyperplasia) had pituitary macroadenoma. Six patients had invasive pituitary adenoma. Transsphenoidal surgery (TSS) was the primary modality of treatment in 13/14 patients, and it achieved remission in 4/13 (30.76%) patients without recurrence over a median follow-up of 7 years. Post-TSS radiotherapy (RT) achieved remission in 3/5 (60%) patients over a median follow-up of 3.5 years. None of the patients received medical management at any point of time.

CONCLUSION

Gigantism is more common in males, and remission can be achieved in the majority of the patients with the help of multimodality treatment (TSS and RT).

Gigantism caused by growth hormone secreting pituitary adenoma

Gigantism indicates excessive secretion of growth hormones (GH) during childhood when open epiphyseal growth plates allow for excessive linear growth. Case one involved a 14.7-year-old boy presented with extreme tall stature. His random serum GH level was 38.4 ng/mL, and failure of GH suppression was noted during an oral glucose tolerance test (OGTT; nadir serum GH, 22.7 ng/mL). Magnetic resonance imaging (MRI) of the brain revealed a 12-mm-sized pituitary adenoma. Transsphenoidal surgery was performed and a pituitary adenoma displaying positive immunohistochemical staining for GH was reported. Pituitary MRI scan was performed 4 months after surgery and showed recurrence/residual tumor. Medical treatment with a long-acting somatostatin analogue for six months was unsuccessful. As a result, secondary surgery was performed. Three months after reoperation, the GH level was 0.2 ng/mL and insulin-like growth factor 1 was 205 ng/mL. Case two involved a 14.9-year-old boy, who was referred to our department for his tall stature. His basal GH level was 9.3 ng/mL, and failure of GH suppression was reported during OGTT (nadir GH, 9.0 ng/mL). Pituitary MRI showed a 6-mm-sized pituitary adenoma. Surgery was done and histopathological examination demonstrated a pituitary adenoma with positive staining for GH. Three months after surgery, the GH level was 0.2 ng/mL and nadir GH during OGTT was less than 0.1 ng/mL. Pituitary MRI scans showed no residual tumor. We present two cases of gigantism caused by a GH-secreting pituitary adenoma with clinical and microscopic findings.

Clinical applications of somatostatin analogs for growth hormone-secreting pituitary adenomas

Excessive growth hormone (GH) is usually secreted by GH-secreting pituitary adenomas and causes gigantism in juveniles or acromegaly in adults. The clinical complications involving cardiovascular, respiratory, and metabolic systems lead to elevated morbidity in acromegaly. Control of serum GH and insulin-like growth factor (IGF) 1 hypersecretion by surgery or pharmacotherapy can decrease morbidity. Current pharmacotherapy includes somatostatin analogs (SAs) and GH receptor antagonist; the former consists of lanreotide Autogel (ATG) and octreotide long-acting release (LAR), and the latter refers to pegvisomant. As primary medical therapy, lanreotide ATG and octreotide LAR can be supplied in a long-lasting formulation to achieve biochemical control of GH and IGF-1 by subcutaneous injection every 4-6 weeks. Lanreotide ATG and octreotide LAR provide an effective medical treatment, whether as a primary or secondary therapy, for the treatment of GH-secreting pituitary adenoma; however, to maximize benefits with the least cost, several points should be emphasized before the application of SAs. A comprehensive assessment, especially of the observation of clinical predictors and preselection of SA treatment, should be completed in advance. A treatment process lasting at least 3 months should be implemented to achieve a long-term stable blood concentration. More satisfactory surgical outcomes for noninvasive macroadenomas treated with presurgical SA may be achieved, although controversy of such adjuvant therapy exists. Combination of SA and pegvisomant or cabergoline shows advantages in some specific cases. Thus, an individual treatment program should be established for each patient under a full evaluation of the risks and benefits.

The GH/IGF-1 axis in ageing and longevity

Secretion of growth hormone (GH), and consequently that of insulin-like growth factor 1 (IGF-1), declines over time until only low levels can be detected in individuals aged ≥60 years. This phenomenon, which is known as the 'somatopause', has led to recombinant human GH being widely promoted and abused as an antiageing drug, despite lack of evidence of efficacy. By contrast, several mutations that decrease the tone of the GH/IGF-1 axis are associated with extended longevity in mice. In humans, corresponding or similar mutations have been identified, but whether these mutations alter longevity has yet to be established. The powerful effect of reduced GH activity on lifespan extension in mice has generated the hypothesis that pharmaceutically inhibiting, rather than increasing, GH action might delay ageing. Moreover, mice as well as humans with reduced activity of the GH/IGF-1 axis are protected from cancer and diabetes mellitus, two major ageing-related morbidities. Here, we review data on mouse strains with alterations in the GH/IGF-1 axis and their effects on lifespan. The outcome of corresponding or similar mutations in humans is described, as well as the potential mechanisms underlying increased longevity and the therapeutic benefits and risks of medical disruption of the GH/IGF-1 axis in humans.

Pituitary gigantism presenting with depressive mood disorder and diabetic ketoacidosis in an Asian adolescent

Hyperglycemia is seldom described in young patients with pituitary gigantism. Here, we describe the case of a 17-year-old Taiwanese boy who developed depressive mood disorder and diabetic ketoacidosis (DKA) at the presentation of pituitary gigantism. The boy complained of lethargy and dysphoric mood in June 2008. He presented at the emergency department with epigastralgia and dyspnea in January 2009. Results of laboratory tests suggested type 1 diabetes mellitus with DKA. However, serum C-peptide level was normal on follow-up. Although he had no obvious features of acral enlargement, a high level of insulin-like growth factor 1 was detected, and a 75 g oral glucose suppression test showed no suppression of serum growth hormone levels. A pituitary macroadenoma was found on subsequent magnetic resonance imaging. The pituitary adenoma was surgically removed, followed by gamma-knife radiosurgery, and Sandostatin long-acting release treatment. He was then administered metformin, 500 mg twice daily, and to date, his serum glycohemoglobin has been <7%.

Hereditary pituitary hyperplasia with infantile gigantism

CONTEXT

We report hereditary pituitary hyperplasia.

OBJECTIVE

The objective of the study was to describe the results of the clinical and laboratory analysis of this rare instance of hereditary pituitary hyperplasia.

DESIGN

The study is a retrospective analysis of three cases from one family.

SETTING

The study was conducted at the National Institutes of Health, a tertiary referral center.

PATIENTS

A mother and both her sons had very early-onset gigantism associated with high levels of serum GH and prolactin.

INTERVENTIONS

The condition was treated by total hypophysectomy.

MAIN OUTCOME MEASURE(S)

We performed clinical, pathological, and molecular evaluations, including evaluation basal and provocative endocrine testing, neuroradiological assessment, and assessment of the pituitary tissue by microscopic evaluation, immunohistochemistry, and electron microscopy.

RESULTS

All three family members had very early onset of gigantism associated with abnormally high serum levels of GH and prolactin. Serum GHRH levels were not elevated in either of the boys. The clinical, radiographic, surgical, and histological findings indicated mammosomatotroph hyperplasia. The pituitary gland of both boys revealed diffuse mammosomatotroph hyperplasia of the entire pituitary gland without evidence of adenoma. Prolactin and GH were secreted by the same cells within the same secretory granules. Western blot and immunohistochemistry demonstrated expression of GHRH in clusters of cells distributed throughout the hyperplastic pituitary of both boys.

CONCLUSIONS

This hereditary condition seems to be a result of embryonic pituitary maldevelopment with retention and expansion of the mammosomatotrophs. The findings suggest that it is caused by paracrine or autocrine pituitary GHRH secretion during pituitary development.

Transformation of a microprolactinoma into a mixed growth hormone and prolactin-secreting pituitary adenoma

Combined prolactin (PRL) and growth hormone (GH) secretion by a single pituitary tumor can occur in approximately 5% of cases. However, in all previously reported patients, combined secretion of both hormones was present at the time of diagnosis. Here we describe a patient initially diagnosed with a pure prolactin-secreting microadenoma, who experienced the progressive apparition of symptomatic autonomous GH secretion while on intermittent long term dopamine agonist therapy. She was operated on, and immunohistochemical analysis of tumor tissue confirmed the diagnosis of pituitary adenoma with uniform co-staining of all cells for both GH and PRL. This patient represents the first documented occurrence of asynchronous development of combined GH and PRL secretion in a pituitary adenoma. Although pathogenic mechanisms implicated remain largely speculative, it emphasizes the need for long term hormonal follow up of patients harboring prolactinomas.

Unusually rapid growth and adult stature in an American hairless terrier puppy

A puppy was evaluated for rapid growth and large stature. Extensive diagnostic evaluation suggested a growth hormone independent disorder. As the sole detected abnormality was elevated leptin concentration, an obesity syndrome causing leptin resistance was speculated to explain the puppy's condition but was not confirmed. Except for large body size, the puppy remained clinically normal.

Excessive growth

Tall stature and excessive growth syndrome are a relatively rare concern in pediatric practice. Nevertheless, it is important to identify abnormal accelerated growth patterns in children, which may be the clue in the diagnosis of an underlying disorder. We present a case of pituitary gigantism in a 2 1/2-year-old child and discuss the signs, symptoms, laboratory findings, and the treatment. Brief discussions on the differential diagnosis of excessive growth/tall stature have been outlined. Pituitary gigantism is very rare in the pediatrics age group; however, it is extremely rare in a child that is less than 3 years of age. The nature of pituitary adenoma and treatment options in children with this condition have also been discussed.

Treatment of pituitary gigantism with the growth hormone receptor antagonist pegvisomant

CONTEXT

Treatment of pituitary gigantism is complex and the results are usually unsatisfactory.

OBJECTIVE

The objective of the study was to describe the results of therapy of three children with pituitary gigantism by a GH receptor antagonist, pegvisomant.

DESIGN

This was a descriptive case series of up to 3.5 yr duration.

SETTING

The study was conducted at a university hospital.

PATIENTS

Patients included three children (one female, two males) with pituitary gigantism whose GH hypersecretion was incompletely controlled by surgery, somatostatin analog, and dopamine agonist.

INTERVENTION

The intervention was administration of pegvisomant.

MAIN OUTCOME MEASURES

Plasma IGF-I and growth velocity were measured.

RESULTS

In all three children, pegvisomant rapidly decreased plasma IGF-I concentrations. Growth velocity declined to subnormal or normal values. Statural growth fell into lower growth percentiles and acromegalic features resolved. Pituitary tumor size did not change in two children but increased in one boy despite concomitant therapy with a somatostatin analog.

CONCLUSIONS

Pegvisomant may be an effective modality for the therapy of pituitary gigantism in children. Titration of the dose is necessary for optimal efficacy, and regular surveillance of tumor size is mandatory.

Growth hormone suppression after an oral glucose load in children

BACKGROUND

GH nonsuppression after oral glucose is diagnostic for GH excess, but normative data are lacking in children. Adult data cannot be extrapolated to children given the pubertal increase in GH concentration. In addition, because GH levels are higher in pubertal girls than boys, nadir GH may differ across gender.

OBJECTIVE

Our objective was to determine whether nadir GH during an oral glucose tolerance test (OGTT) is gender and pubertal stage specific. We hypothesized that nadir GH would be higher in girls, and at the pubertal stage known to correspond with peak height velocity (Tanner 2-3 in girls and Tanner 3-4 in boys) and maximal GH concentrations. SUBJECTS/ METHODS: A 2-h OGTT using 2.35 g/kg oral glucose (maximum 100 g) was performed in 64 girls and 43 boys, 9-17 yr (10th-90th percentiles for body mass index). Girls were grouped as group 1 (Tanner 1), group 2 (Tanner 2-3), and group 3 (Tanner 4-5), and boys as group 1 (Tanner 1-2), group 2 (Tanner 3-4), and group 3 (Tanner 5).

RESULTS

Nadir GH was higher in girls than boys, and in group 2 girls and boys than the other two groups. The upper limit for nadir GH was highest in group 2 girls (1.57 ng/ml), and lower for the other two groups of girls (0.64 ng/ml), and for boys (0.50 ng/ml). All but one girl, and all boys suppressed to less than 1.0 ng/ml. There were 16 girls and five boys who had a nadir GH of more than 0.3 ng/ml.

CONCLUSION

GH suppression after oral glucose is gender and pubertal stage specific.

Growth hormone excess with onset in adolescence: clinical appearance and long-term treatment outcome

BACKGROUND

Limited data are available on clinical presentation and treatment strategy in patients with GH-secreting adenomas with onset in adolescence.

OBJECTIVE

To report results of diagnosis and treatment in adolescents with GH and IGF-I excess.

DESIGN

Analytical, observational, retrospective.

SUBJECTS

Thirteen patients (five females and eight males, age 15-20 years) all with macroadenoma (two extrasellar, 11 invasive).

MAIN OUTCOME MEASURES

Height, body mass index (BMI), GH and IGF-I levels, tumour volume at diagnosis and after treatment.

INTERVENTIONS

Transsphenoidal surgery, octreotide subcutaneous (OCT, 0.3-0.8 mg/day), octreotide-LAR i.m. (LAR, 20-30 mg/q28 days), lanreotide i.m. (LAN, 60-90 mg/q28 days), bromocriptine (BRC, 5 mg/day), cabergoline (CAB, 1-2 mg/week).

RESULTS

Concomitant hyperprolactinaemia was found in eight patients (61.5%). All girls presented with amenorrhoea, which was associated with galactorrhoea in two patients; all boys presented with symptoms of tumour mass compression such as visual disturbance or headache; two girls also had these symptoms. Height at diagnosis was above the 97th centile in four of five girls and in six of eight boys. None of the patients had altered lipid profile while homeostasis model assessment of insulin resistance (HOMA-IR; 2.8 +/- 0.9) and beta-cell function (HOMA-beta, 207.6 +/- 98.1%) were higher than predicted (1% and 100%, respectively). First-line treatment was surgery in two patients and somatostatin analogues associated with dopaminergic drugs in 11 patients. None of the patients operated on were cured while six of 11 patients receiving pharmacotherapy (6-24 months) were controlled. In these six, tumour volume was reduced by 51.0 +/- 25.2% (median 51.5%). As second-line treatment, all the 11 patients treated with somatostatin analogues underwent surgical removal of their tumours. Surgery was successful in four patients and second-line pharmacotherapy in six patients. One patient was lost at follow-up and two patients maintained active acromegaly despite different treatment schedules; both patients were then treated with radiotherapy. At the last follow-up, there was a significant decrease in insulin levels, HOMA-IR and HOMA-beta without any change in lipid profile.

CONCLUSIONS

The clinical presentation of GH-secreting adenomas in adolescent girls is associated with menstrual disturbances and in boys with symptoms of mass effects; tall stature is characteristic in both. First-line treatment with depot somatostatin analogues followed by surgery and then by a second course of somatostatin analogues was successful and safe in 11 of 13 patients.

Pituitary adenomas in childhood: development and diagnosis

Pituitary adenomas account for approximately 2.7% of all supratentorial tumors in the pediatric age range, and children are more likely than adults to develop a functioning adenoma. X chromosome inactivation studies indicate that pituitary adenomas arise from the clonal expression of a single mutated cell, and various intracellular mechanisms contribute to tumoral transformation. Functional pituitary tumors in childhood result in physical and biochemical effects of excess production of the oversecreted hormone, such as ACTH, prolactin, human growth hormone, TSH, LH, or FSH. In the clinical approach to pituitary adenomas, it is important to establish the presence of hormonal excess prior to undertaking imaging studies.

Acromegaloidism with normal growth hormone secretion associated with X-tetrasomy

We reported a case of a 26-year-old female who was referred to our clinic with the diagnosis of possible acromegaly. She was born from a term pregnancy by forceps delivery. The patient was diagnosed as having hip luxation at one month and spoke her first word at 15 months. She had been diagnosed at the age of 9 years old as having perinatal encephalopathy with intellectual and motor affectation. Since this period of time she has undergone an insidious change in her appearance, mainly comprising progressive coarsening of the face. For this reason she was submitted to our clinic with presumed acromegaly. Dynamic tests of growth hormone secretion ruled out such a diagnosis. The Patient was considered as having "acromegaloidism", a term used for patients whom manifest clinical features of acromegaly but do not present a demonstrable growth hormone hypersecretion. Subsequently cytogenetic evaluation revealed an infrequent chromosome pattern: X-Tetrasomy. In the present article a differential diagnosis of acromegaloidism and the potential role of genes present on X-chromosome involved in human growth such as SHOX gene are discussed. Overdosification of SHOX gene might explain tall stature of girls with X-tetrasomy. Our observation suggested that X-tetrasomy should be considered in the differential diagnosis of acromegaloidism. Furthermore, this may lead to the identification of new genes in the X-chromosome that are important for growth of facial structures.

Pituitary adenomas in childhood

Pituitary adenomas are common tumors composed of adenohypophysial cells. Although they usually arise in the sella turcica, they may occasionally be ectopic. Pituitary adenomas are rarely diagnosed in childhood and adolescence, but their mass effect and endocrine abnormalities can compromise both quality and length of life. Many signs or symptoms of pituitary adenoma, complained of in adulthood, not became evident during adolescence, suggesting true prevalence of this tumor in teenagers is higher than expected. Pititury adenoma occuring during adolescence are associated with features or therapeutic needs sometimes different from those occuring in adulthood. At the onset of disease, delay in growth was rarely observed in teenagers with pituitary adenomas. Many girls complain of oligoamenorrhoea and galactorrhoea, while headache and delay in pubertal development are the most commons features in boys. Hypopituitarism is occasionally encountered in adolescence. Early diagnosis and appropriate choice of therapy are necessary to avoid permanent endocrine complications of disease and its treatment.

A provisionally unique syndrome of macrosomia, bone overgrowth, macrocephaly, and tall stature

We report a young man with intrauterine macrosomia, macrocephaly, and bony abnormalities. Excessive growth continued throughout infancy and childhood. Bone age was advanced. He developed contractures of the large joints and was confined to a wheelchair. Extensive laboratory studies, repeated on multiple occasions were all normal. Intellectually, he was normal. His near final height was 234 cm. The constellation of findings in this patient is at variance with previously described syndromes of tall stature. We postulate that excessive size and bone overgrowth in this young man is caused by a receptor/post-receptor abnormality involving a growth on/off mechanism at the cellular level.

Clinical and molecular features of the Carney complex: diagnostic criteria and recommendations for patient evaluation

Carney complex is a multiple neoplasia syndrome featuring cardiac, endocrine, cutaneous, and neural tumors, as well as a variety of pigmented lesions of the skin and mucosae. Carney complex is inherited as an autosomal dominant trait and may simultaneously involve multiple endocrine glands, as in the classic multiple endocrine neoplasia syndromes 1 and 2. Carney complex also has some similarities to McCuneAlbright syndrome, a sporadic condition that is also characterized by multiple endocrine and nonendocrine tumors. Carney complex shares skin abnormalities and some nonendocrine tumors with the lentiginoses and certain of the hamartomatoses, particularly Peutz-Jeghers syndrome, with which it shares mucosal lentiginosis and an unusual gonadal tumor, large-cell calcifying Sertoli cell tumor. Careful clinical analysis has enabled positional cloning efforts to identify two chromosomal loci harboring potential candidate genes for Carney complex. Most recently, at the 17q22-24 locus, the tumor suppressor gene PRKAR1A, coding for the type 1alpha regulatory subunit of PKA, was found to be mutated in approximately half of the known Carney complex kindreds. PRKAR1A acts a classic tumor suppressor gene as demonstrated by loss of heterozygosity at the 17q22-24 locus in tumors associated with the complex. The second locus, at chromosome 2p16, to which most (but not all) of the remaining kindreds map, is also involved in the molecular pathogenesis of Carney complex tumors, as demonstrated by multiple genetic changes at this locus, including loss of heterozygosity and copy number gain. Despite the known genetic heterogeneity in the disease, clinical analysis has not detected any corresponding phenotypic differences between patients with PRKAR1A mutations and those without. This article summarizes the clinical manifestations of Carney complex from a worldwide collection of affected patients and also presents revised diagnostic criteria for Carney complex. In light of the recent identification of mutations in the PRKAR1A gene, an estimate of penetrance and recommendations for genetic screening are provided.