Hypothalamic hamartoma: a source of luteinizing-hormone-releasing factor in precocious puberty

Advances in epileptic network findings of hypothalamic hamartomas

Hypothalamic hamartomas (HHs) are congenital developmental malformations located in the hypothalamus. They are associated with a characteristic clinical manifestation known as gelastic seizures (GS). However, the traditional understanding of HHs has been limited, resulting in insufficient treatment options and high recurrence rates of seizures after surgery. This is consistent with the network hypothesis of focal epilepsy that the epileptogenic zone is not only limited to HH but may also involve the distant cerebral cortex external to the HH mass. The epilepsy network theory, on the other hand, provides a new perspective. In this study, we aim to explore HH-related epilepsy as a network disease, challenging the conventional notion of being a focal lesional disease. We analyze various aspects of HHs, including genes and signaling pathways, local circuits, the whole-brain level, phenotypical expression in terms of seizure semiology, and comorbidities. By examining HHs through the lens of network theory, we can enhance our understanding of the condition and potentially identify novel approaches for more effective management and treatment of epilepsy associated with HHs.

Precocious Puberty: Types, Pathogenesis and Updated Management

Precocious puberty (PP) means the appearance of secondary sexual characters before the age of eight years in girls and nine years in boys. Puberty is indicated in girls by the enlargement of the breasts (thelarche) in girls and in boys by the enlargement of the testes in either volume or length (testicular volume = 4 mL, testicular length = 25 mm, or both). Two types of PP are recognized - namely central PP (CPP) and peripheral PP (PPP). This paper aims to describe the clinical findings and laboratory workup of PP and to illustrate the new trends in the management of precocious sexual maturation. Gonadotropin-releasing hormone (GnRH)-independent type (PPP) refers to the development of early pubertal maturation not related to the central activation of the hypothalamic-pituitary-gonadal (HPG) axis. It is classified into genetic or acquired disorders. The most common forms of congenital or genetic causes involve McCune-Albright syndrome (MAS), familial male-limited PP, and congenital adrenal hyperplasia. The acquired causes include exogenous exposure to androgens, functioning tumors or cysts, and the pseudo-PP of profound primary hypothyroidism. On the other hand, CPP is the most common and it is a gonadotropin-dependent form. It is due to premature maturation of the HPG axis. CPP may occur as genetic alterations, such as MKRN3, DLK1, or KISS1;as a part of mutations in the epigenetic factors that regulate the HPG axis, such as Lin28b and let-7; or as a part of syndromes, central lesions such as hypothalamic hamartoma, and others. A full, detailed history and physical examination should be taken. Furthermore, several investigations should be conducted for both types of PP, including the estimation of serum gonadotropins such as luteinizing and follicle-stimulating hormones and sex steroids, in addition to a radiographic workup and thyroid function tests. Treatment depends on the type of PP: Long-acting GnRHa, either intramuscularly or implanted, is the norm of care for CPP management, while in PPP, especially in congenital adrenal hyperplasia, the goal of management is to suppress adrenal androgen secretion by glucocorticoids. In addition, anastrozole and letrozole - third-generation aromatase inhibitors - are more potent for MAS.

Advances in hypothalamic hamartoma research over the past 30 years (1992-2021): a bibliometric analysis

Background

Hypothalamic hamartoma (HH) is a rare intracranial disease whose manifestations include gelastic seizures and precocious puberty. The diagnosis and treatment of HH have changed substantially over the past three decades as medical care has improved. Bibliometrics can reveal the evolution and development of a scientific field.

Methods

Documents on HH were retrieved from the Web of Science Core Collection (WoSCC) database on September 8, 2022. The search terms were as follows: "hypothalamic hamartoma" or "hamartoma of the hypothalamus" or "hypothalamic hamartomas." The types of documents were restricted to articles, case reports, and reviews. VOSviewer, CiteSpace, and the R package "bibliometrix" were used for a bibliometric analysis.

Results

A total of 667 independent documents on HH were obtained from the WoSCC database. The most common types of documents were articles (n = 498, 75%) and reviews (n = 103, 15%). The number of annual publications fluctuated but showed an upward trend overall, and the annual growth rate was 6.85%. The cumulative publication data indicated that the most influential journals in the HH field include Epilepsia, Epileptic Disorders, Child's Nervous System, Neurosurgery, and the Journal of Neurosurgery. Kerrigan JF, Ng YT, Rekate HL, Regis J, and Kameyama S were among the most prominent authors in the field of HH, with numerous publications and citations. American research institutions, especially the Barrow Neurological Institute, occupied a pivotal position in HH research. Other countries and institutions were catching up and producing considerable research results. Research on HH has steadily switched its emphasis from Pallister-Hall syndrome (PHS) and precocious puberty to epilepsy and new diagnostic and therapeutic techniques, including Gamma Knife, laser ablation, and interstitial thermal therapy.

Conclusion

HH remains a special neurological disease with significant research prospects. The development of novel technologies, including MRI-guided laser-induced thermal therapy (MRg-LiTT) and stereotactic radiofrequency thermocoagulation (RF-TC), has enabled the efficient treatment of gelastic seizures in HH while minimizing the risks associated with craniotomies. Through bibliometric analysis, this study points out the direction for future HH research.

Central precocious puberty: Recent advances in understanding the aetiology and in the clinical approach

Central precocious puberty (CPP) results from early activation of the hypothalamic-pituitary-gonadal (HPG) axis. The current state of knowledge of the complex neural network acting at the level of the hypothalamus and the GnRH neuron to control puberty onset has expanded, particularly in the context of molecular interactions. Along with these advances, the knowledge of pubertal physiology and pathophysiology has also increased. This review focuses on regulatory abnormalities occurring at the hypothalamic level of the HPG axis to cause CPP. The clinical approach to diagnosis of puberty and pubertal disorders is also reviewed, with a particular focus on aetiologies of CPP. The recent identification of mutations in MKRN3 and DLK1 in familial as well sporadic forms of CPP has changed the state of the art of the approach to patients with CPP. Genetic advances have also had important repercussions beyond consideration of puberty alone. Syndromic disorders and central nervous system lesions associated with CPP are also discussed. If untreated, these conditions may lead to adverse physical, psychosocial and medical outcomes.

Is surgery effective for treating hypothalamic hamartoma causing isolated central precocious puberty? A systematic review

The aim of this review was to determine the role of surgery in treating hypothalamic hamartoma (HH) causing isolated central precocious puberty (CPP). Literature review was done according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Patients with isolated CPP due to HH, managed with surgical resection, were included. We found 33 studies, reporting 103 patients (76 pedunculated, 27 sessile). Patients were considered "cured" if the symptoms of PP had regressed and the hormone profile had normalized after surgery. Indications for surgery included hamartoma deemed surgically resectable (n-12), for the purpose of tissue diagnosis (n-3), partial response/failure of preoperative therapy (n-9), and unable to afford/to avoid long-term medical therapy (n-7). The extent of resection was total (TR) (n-39), near total/subtotal (NTR/STR) (n-20), partial (PR) (n-35), or unspecified (n-9). On follow-up (range: 3 months-16 years), 73.6% (56/76) of patients with pedunculated HH were cured, while 17.1% (13/76) had partial relief. Only 3/27 (11.1%) of patients with sessile HH were cured. All patients with a pedunculated hamartoma who underwent TR (n=36) improved, with 88.88% cured of the symptoms. Surgery had no effect in 17/23 (73.9%) patients with sessile HH who underwent PR. Psychological symptoms improved in 10/11 patients. There was no mortality. Permanent complications, in the form of 3rd nerve palsy, occurred in 3.7% (2/54) of the patients. To conclude, in the current era of availability of GnRH analogs, surgical resection in a subset of patients may be acceptable especially for small pedunculated hamartomas.

Hypothalamic hormone-producing tumors

The hypothalamus is functional neuroendocrine tissue that is responsible for the synthesis and secretion of peptide hormones that regulate the pituitary and other endocrine functions. Endocrine tumors of the hypothalamus are rare but they provide a model for tumors that have both structural and functional effects. Patients with hypothalamic endocrine tumors suffer mass effects including headaches, visual disturbances, and endocrine dysfunction due to structural damage to hypothalamic nuclei, which regulate appetite, temperature, diurnal rhythms and emotions. In addition, these tumors can secrete hormones that can cause acromegaly, Cushing disease, hyperprolactinemia, and the syndrome of inappropriate antidiuresis. Morphologic classification of these tumors has provided evidence for two classes of tumors, gangliocytomas that are composed of large neurons and neurocytomas that are comprised of small cells; these resemble the variants of magnocellular and parvocellular neurons in the hypothalamic nuclei. Biomarkers are used to classify these tumors and achieve accurate structure-function correlations. While surgery remains the mainstay of therapy, novel medical and radiopharmaceutical approaches are available for patients with progressive and/or unresectable tumors.

Hamartoma of hypothalamus presented as precocious puberty and epilepsy in a 10-year-old girl

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Hamartoma of the hypothalamus may presents as central precocious puberty and gelastic epilepsy.

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It may be asymptomatic for long period.

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MRI is diagnostic in most of the cases.

Background

Hamartoma of the hypothalamus represents a well-known but rare cause of central precocious puberty and gelastic epilepsy. Due to the delicate site in which a tumor is located, surgery is often difficult and associated with considerable risks.

Case presentation

10-Year old girl presented with early and regular menstruation at the age of 1 year each cycle lasted for 3 days. She had developed breast, axillary and pubic hair at the age of five, and seven years respectively, with history of difficulty in speech especially articulation and epilepsy since childhood for which she is on medications. She had attacks of an inappropriate laugh. The laboratory tests were consisted with central precocious puberty, MRI shows suprasellar mass. She received leuprolide and antiepileptic medicines until surgery planned. Surgery was done with complete resection, with histopathology showing hypothalamic hamartoma. After surgery, there was complete remission of seizure.

She developed recurrence 4 years later and she is currently on anticonvulsant medications with few attacks of convulsions per week, and she has intellectual disabilities and low school performance.

Conclusion

The treatment of hypothalamic hamartoma associated with generalized epilepsy has been found to improve seizures and behavioral disturbances with an acceptable morbidity rate by using a variety of surgical approaches. Partial resection of a tumor may be sufficient to reduce seizure frequency and to improve behavior and quality of life with few side effects. Best outcomes are achieved when the patients are managed by an experienced multidisciplinary team and lifelong follow up is recommended.

Hypothalamic hamartomas: A comprehensive review of the literature - Part 1: Neurobiological features, clinical presentations and advancements in diagnostic tools

Hypothalamic hamartomas (HH) are rare, non-neoplastic heterotopic tissues which contains normal neurons and glia including oligodendrocytes and fibrillary astrocytes but in an abnormal distribution. They arise from the floor of the third ventricle, tuber cinereum, or mammillary bodies. Estimated incidence ranges from 1 in 50,000-1 in 1,000,000. Hypothalamic hamartomas are associated with different clinical presentations including various types of seizures, most characteristically; the gelastic seizures, precocious puberty, cognitive impairment, and behavioral changes. In this review, the authors discuss advancements in different diagnostic elements of hypothalamic hamartoma; including clinical features, EEG findings, and neuroimaging techniques. Moreover, different classifications described in the literature will be discussed.

Hypothalamic Endocrine Tumors: An Update

The hypothalamus is the site of synthesis and secretion of a number of endocrine peptides that are involved in the regulation of hormonal activity of the pituitary and other endocrine targets. Tumors of the hypothalamus have been recognized to have both structural and functional effects including hormone hypersecretion. The classification of these tumors has advanced over the last few years, and biomarkers are now available to classify these tumors and provide accurate structure-function correlations. This review provides an overview of tumors in this region that is critical to metabolic homeostasis with a focus on advances in the diagnosis of gangliocytomas, neurocytomas, and pituicytomas that are unique to this region.

Hypothalamic hamartoma with epilepsy: Review of endocrine comorbidity

The most common, and usually the only, endocrine disturbance in patients with hypothalamic hamartoma (HH) and epilepsy is central precocious puberty (CPP). The mechanism for CPP associated with HH may relate to ectopic generation and pulsatile release of gonadotropin-releasing hormone (GnRH) from the HH, but this remains an unproven hypothesis. Possible regulators of GnRH release that are intrinsic to HH tissue include the following: (1) glial factors (such as transforming growth factor α[TGFα) and (2) γ-aminobutyric acid (GABA)-mediated excitation. Both are known to be present in surgically-resected HH tissue, but are present in patients with and without a history of CPP, suggesting the possibility that symptoms related to HH are directly associated with the region of anatomic attachment of the HH to the hypothalamus, which determines functional network connections, rather than to differences in HH tissue expression or pathophysiology. CPP associated with HH presents with isosexual development prior to the age of 8 years in girls and 9 years in boys. It is not uncommon for CPP with HH to present in children at an earlier age in comparison to other causes of CPP, including in infancy. Surgical resection of the HH can be effective for treating CPP, but is reserved for patients with intractable epilepsy, since GnRH agonists are widely available and effective treatment. Other endocrine disturbances with HH are rare, but can include growth hormone deficiency, hypothyroidism, and adrenal insufficiency. Diabetes insipidus is commonly encountered postoperatively, but is not observed with HH prior to surgical intervention.

An 11-month-old girl with central precocious puberty caused by hypothalamic hamartoma

Central precocious puberty (CPP) is caused by premature activation of the hypothalamic-gonadal axis, and must be treated adequately. In particular, CPP that occurs at a relatively young age or in boys is likely to be caused by an organic lesion. Hypothalamic hamartoma (HH) is the most common organic cause of CPP. The present case report describes an 11-month-old female infant who presented with vaginal bleeding and rapidly progressive secondary sex characteristics from the age of 6 months. She was diagnosed with CPP following the detection of HH via magnetic resonance imaging. The infant girl was successfully treated with gonadotropin-releasing hormone agonist. After 6 months, her breast had regressed and clinical and radiological follow-up demonstrated stable findings with no evidence of tumor growth or secondary sexual characteristics until the fourth year after the initiation of treatment. This patient is the one of the youngest infants presenting with CPP and HH in Korea; treatment was successful over a relatively long follow-up period.

Hypothalamic hamartoma simulating a suprasellar arachnoid cyst: resolution of precocious puberty following microsurgical lesion resection

Hypothalamic hamartomas (HHs) are rare developmental lesions arising from the inferior hypothalamus that may cause gelastic seizures and central precocious puberty. Cystic changes in HHs are rare, usually occurring in giant lesions. The authors describe an unusual case of cystic HH masquerading as a suprasellar arachnoid cyst in an 18-month-old girl presenting with precocious puberty. Microsurgical removal of the lesion led to complete resolution of the precocious puberty on long-term follow-up. This case is the first reported HH with pathological demonstration of corticotropin-releasing hormone immunostaining in the solid tumor and glial cells in the cyst wall of the lesion. The clinical and radiological characteristics of HHs are reviewed, along with the unique surgical strategies used to manage cystic lesions in the suprasellar region.

Successful treatment of hyperphagia by resection of a hypothalamic hamartoma

Hypothalamic hamartomas (HHs) are benign lesions that are often associated with central precocious puberty and may present with gelastic seizures. Treatment modalities for HH include medical therapy with long-term gonadotropin-releasing hormone analogs or resection. The authors report the case of a 7-year-old girl who was diagnosed with an HH due to precocious puberty and was treated medically with a gonadotropin-releasing hormone analog for 3 years. Despite normalization of her plasma levels of luteinizing hormone, follicle-stimulating hormone, and estradiol and arrest of her precocious puberty, the patient developed progressive weight gain associated with extreme hyperphagia and morbid obesity by the age of 10 years. Her compulsive eating patterns were refractory to counseling and other interventions attempted by her parents and physicians. After resection of the HH, her hyperphagia resolved and her weight stabilized. To the authors' knowledge, this is the first report describing resection of an HH for the purpose of treating hyperphagia and obesity.

Functional rundown of gamma-aminobutyric acid(A) receptors in human hypothalamic hamartomas

OBJECTIVE

Human hypothalamic hamartomas (HHs) are highly associated with treatment-resistant gelastic seizures. HHs are intrinsically epileptogenic, although the basic cellular mechanisms responsible for seizure activity are unknown. Altered gamma-aminobutyric acid (GABA) function can contribute to epileptogenesis in humans and animal models. Recently, functional GABA(A) receptor (GABA(A) R) rundown has been described in surgically resected human temporal lobe epilepsy tissue. We asked whether functional GABA(A) R rundown also occurs in human HH neurons.

METHODS

GABA(A) R-mediated currents were measured using perforated patch-clamp recordings in single neurons acutely dissociated from surgically resected HH tissue. In addition, functional GABA(A) Rs were expressed in Xenopus oocytes after microinjection with membrane fractions from either HH or control hypothalamus, and were studied with 2-electrode voltage-clamp recordings.

RESULTS

Perforated patch-clamp recordings in dissociated HH neurons showed that repetitive exposure to GABA (5 consecutive exposures to 0.1 mM GABA with 1-second duration and at 20-second intervals) induced a time-dependent rundown of whole-cell currents in small HH neurons, whereas large HH neurons showed much less rundown using the same protocol. Functional rundown was not observed in HH neurons with repetitive exposure to glycine or glutamate. Two-electrode voltage-clamp recordings (6 consecutive exposures to 1 mM GABA with 10-second duration and at 40-second intervals) induced GABA current rundown in Xenopus oocytes microinjected with HH membrane proteins, but not in the oocytes expressing hypothalamic membrane proteins derived from human autopsy controls. Functional rundown of GABA currents was significantly attenuated by intracellular application of adenosine triphosphate or the nonspecific phosphatase inhibitor, okadaic acid.

INTERPRETATION

Neurons from surgically resected human HH demonstrate functional rundown of GABA(A) R-mediated transmembrane currents in response to GABA agonist exposure. Rundown may be a marker for impaired GABAergic function and a contributing mechanism for seizure genesis within HH tissue.

Two cases of precocious puberty associated with hypothalamic hamartoma

Hypothalamic hamartoma (HH) is a congenital malformation diagnosed based on magnetic resonance imaging (MRI) and histological findings; it is often associated with central precocious puberty (CPP), gelastic seizures, abnormal behavior and mental retardation. In the present paper, we report our retrospective hypothesis that there is a relationship between symptoms and therapy, as well as the treatment for HH, and describe two cases of HH associated with CPP. Both cases had sessile masses located in the interpeduncular cistern, with extension to the hypothalamus on MRI (1.2 × 1.5 cm and 2.0 × 2.5 cm, respectively). The first case had intractable seizures, while the second had no seizures with paroxysmal discharge. In both patients, the hamartomas were partially removed, by γ-knife and surgical operation in the first case and surgically in the second, and a gonadotropin releasing hormone (GnRH) analogue was prescribed. One case showed improvement of both intelligence quotient (IQ) score and seizures, and the other showed improvements in IQ and abnormal behavior. It was difficult to determine any topology/symptom relationships. Surgery and GnRH analogue treatment can alleviate seizures, abnormal behavior and mental retardation associated with HH.

Central precocious puberty due to hypothalamic hamartomas correlates with anatomic features but not with expression of GnRH, TGFalpha, or KISS1

BACKGROUND/AIMS

Hypothalamic hamartomas are the most common identifiable cause of central precocious puberty (CPP). Hamartoma characteristics proposed to be associated with CPP include specific anatomic features and expression of molecules such as gonadotropin-releasing hormone (GnRH), transforming growth factor alpha (TGFalpha), and GRM1A, which encodes the type 1 metabotropic glutamate receptor alpha isoform. We sought to determine whether hamartomas that cause CPP could be distinguished by anatomic features, expression of these molecules, or expression of KISS1, whose products signal through the receptor GPR54 to stimulate GnRH release.

METHODS

Clinical records and radiologic images were reviewed for 18 patients who underwent hamartoma resection for intractable seizures; 7 had precocious puberty. Resected tissue was examined for expression of GnRH, GnRH receptor (GnRHR), TGFalpha, KISS1, GPR54, and GRM1A.

RESULTS

Hypothalamic hamartomas associated with CPP were more likely to contact the infundibulum or tuber cinereum and were larger than hamartomas not associated with CPP. GnRH, TGFalpha, and GnRHR were expressed by all hamartomas studied. Expression of KISS1, GPR54, and GRM1A did not differ significantly between hamartomas associated and not associated with CPP.

CONCLUSION

Anatomic features rather than expression patterns of candidate molecules distinguish hypothalamic hamartomas that are associated with CPP from those that are not.

Precocious puberty due to rathke cleft cyst in a child

OBJECTIVE

To report a case of a child with precocious puberty attributable to Rathke cleft cyst (RCC).

METHODS

The clinical features, laboratory results, and findings on ultrasonography of the pelvis and magnetic resonance imaging of the pituitary gland are presented.

RESULTS

A 16-month-old child had breast enlargement, height increase, and an increase in growth velocity. On examination, she was found to have Tanner stage 3 breast development, and her vaginal mucosa was estrogenized. Her height was above the 97th percentile. Biochemically, she was diagnosed as having central precocious puberty, and magnetic resonance imaging of her pituitary gland disclosed RCC. Treatment with leuprolide resulted in normalization of her growth rate and regression of the breast development; the vaginal mucosa also became unestrogenized.

CONCLUSION

Although RCC is a relatively common finding, it is a rare cause of precocious puberty. Magnetic resonance imaging of the pituitary gland should be performed in all children younger than 6 years of age who have precocious puberty, in an effort to detect any organic lesions.

Central precocious puberty due to hypothalamic hamartoma in a 7-month-old infant girl

Hypothalamic hamartomas (HH) are rare congenital lesions of the tuber cinereum presenting with the classic triad of gelastic epilepsy, central precocious puberty (CPP) and developmental delay. In light of the important and diverse consequences of precocious puberty for affected children and their families, a correct diagnosis without delay is imperative. We present here a rare case of a 7-month-old infant girl with CPP and HH who was successfully treated with depot gonadotropin-releasing hormone (GnRH) analogue is presented.

Transcallosal resection of hypothalamic hamartoma for gelastic epilepsy

INTRODUCTION

Hypothalamic hamartomas (HHs) are commonly associated with severe epilepsy resistant to anticonvulsant therapy. Historically, surgical resection of HHs resulted in considerable morbidity.

DISCUSSION

Two series of patients who successfully underwent resection using a transcallosal approach have now been published; we report the first UK experience of this technique in a series of five patients with HHs and gelastic epilepsy resistant to anticonvulsant therapy. Patients were assessed pre- and postoperatively for seizure activity, endocrine function, ophthalmology, and neurocognitive function. Two patients had precocious puberty and all had evidence of developmental delay and behavioral problems. Postoperatively, all children experienced at least a 50% reduction in seizure frequency with abolition of major seizure types; one child remains seizure-free. One child developed a mild postoperative right hemiparesis and one developed transient diabetes insipidus.

CONCLUSION

There were no adverse developmental effects of surgery. Transcallosal resection of HHs ameliorates resistant epilepsy syndromes associated with HH.

Hypothalamic Hamartoma and Infantile Spasms

PURPOSE

A small number of patients with hypothalamic hamartoma (HH) present with infantile spasms (IS) as an initial or early seizure type. We describe the clinical features of IS associated with HH.

METHODS

Our series of patients with HH and epilepsy was reviewed to identify cases with a history of IS. The clinical features and neuroradiological findings in this study group were compared to a control group of patients with HH and refractory epilepsy, but without a history of IS.

RESULTS

We identified six patients with HH and a history of IS in this series (n = 122, 4.9%). Five of the six are male. Four of the six patients (67%) developed IS as their first seizure type. The mean age for onset of IS was 6.2 months (range 4-9 months). Results of electroencephalographic (EEG) study at the time of IS diagnosis showed hypsarrhythmia in two (33%). Five patients were treated with adrenocorticotropic hormone (ACTH), and four of the five (80%) responded with control of IS. However, these patients developed other seizure types, and were ultimately refractory to medical management. Aside from the IS, no significant differences in clinical and imaging features were determined between the study group and the control group.

CONCLUSIONS

HH should be included in the differential diagnosis for infants presenting with IS. These patients may have hypsarrhythmia on initial EEG, and may respond to ACTH treatment with improvement of IS. However, all became refractory with other seizure types, more commonly seen in HH patients. Focal pathologies associated with IS may be subcortical, as well as cortical, in nature. We have not identified any predictive features for the occurrence of IS in the HH population.

Imaging of sellar and parasellar lesions

The sellar and parasellar region is an anatomically complex area where a number of neoplastic, infectious, inflammatory, developmental and vascular pathologies can occur. Differentiation among various etiologies may not always be easy, since many of these lesions may mimic the clinical, endocrinologic and radiologic presentations of pituitary adenomas. The diagnosis of sellar lesions involves a multidisciplinary effort, and detailed endocrinologic, ophthalmologic and neurologic testing are essential. CT and, mainly, MRI are the imaging modalities to study and characterise normal anatomy and the majority of pathologic processes in this region. We here provide an overview of the most relevant MRI and CT characteristics together with clinical findings of pituitary tumors, vascular, inflammatory and infectious lesions found in the sellar/parasellar region in order to propose an appropriate differential diagnosis.

Early onset of puberty: tracking genetic and environmental factors

Under physiological conditions, factors affecting the genetic control of hypothalamic functions are predominant in determining the individual variations in timing of pubertal onset. In pathological conditions, however, these variations can involve different genetic susceptibility and the interaction of environmental factors. The high incidence of precocious puberty in foreign children migrating to Belgium and the detection in their plasma of a long-lasting 1,1,1-trichloro-2,2-bis(4-chlorophenyl) ethane (DDT) residue suggest the potential role of environmental endocrine disrupting chemicals in the early onset of puberty. This hypothesis was confirmed by experimental data showing that temporary exposure of immature female rats to DDT in vivo results in early onset of puberty. We compared the gene expression profile of hypothalamic hamartoma associated or not with precocious puberty in order to identify gene networks responsible for both hamartoma-dependent sexual precocity and the onset of normal human puberty. In conclusion, pathological variations in the timing of puberty may provide unique information about the interactions of either environmental conditions or genetic susceptibility with the hypothalamic mechanism controlling the onset of sexual maturation, as shown by examples of precocious puberty following exposure to endocrine disrupters or due to hypothalamic hamartoma.

Hypothalamic Hamartoma

The incidence of hypothalamic hamartomas (HHs) has increased since the introduction of magnetic resonance (MR) imaging. The etiology of this anomaly and the pathogenesis of its peculiar symptoms remain unclear, but recent electrophysiological, neuroimaging, and clinical studies have yielded important data. Categorizing HHs by the degree of hypothalamic involvement has contributed to the accurate prediction of their prognosis and to improved treatment strategies. Rather than undergoing corticectomy, HH patients with medically intractable seizures are now treated with surgery that targets the HH per se, e.g. HH removal, disconnection from the hypothalamus, stereotactic irradiation, and radiofrequency lesioning. Although surgical intervention carries risks, total eradication or disconnection of the lesion leads to cessation or reduction of seizures and improves the cognitive and behavioral status of these patients. Precocious puberty in HH patients is safely controlled by long-acting gonadotropin-releasing hormone agonists. The accumulation of knowledge regarding the pathogenesis of symptoms and the development of safe, effective treatment modalities may lead to earlier intervention in young HH patients and prevent the decline in their cognitive abilities and quality of life. This review of hypothalamic hamartomas presents current classifications, pathophysiologies, and treatment modalities.

Hypothalamic hamartoma with precocious puberty

Hypothalamic hamartoma is a rare congenital nonneoplastic heterotopia consisting of neurons, glial cells and fiber bundles. Clinically, most patients with hypothalamic hamartomas present with precocious puberty and/or gelastic epilepsy. We report an interesting case of hypothalamic hamartoma causing precocious puberty in a young male. The lesion was excised totally through frontotemporal craniotomy and transSylvian approach without any added morbidity.

Hypothalamic hamartomas: seven cases and review of the literature

Hypothalamic hamartomas constitute rare developmental lesions associated with gelastic epilepsy and/or precocious puberty (PP). We elected to review cases encountered at our center (7 patients) and the existing literature (277 patients) to obtain a better understanding of the clinical aspects, pathogenesis, and treatment of this entity. Evidence suggests that gelastic seizures are due to intrinsic epileptogenicity. The cause of the subsequent development of other seizure types, cognitive decline, and diffuse spike-and-wave pattern remains unresolved and is addressed. Anticonvulsants often fail to control seizures and different surgical options are available. Available evidence suggests that a resection through a subtemporal approach is best for lesions that are pedunculated or with a significant prepontine component, while a transcallosal approach is more appropriate for sessile lesions with an intraventricular component. Gamma knife surgery may be especially useful for small sessile lesions, failed partial resections, or patients not appropriate or refusing open surgery.

Cranial MRI scans are indicated in all girls with central precocious puberty

AIMS

(1) To assess the value of cranial magnetic resonance imaging (MRI) scans in the investigation of girls with central precocious puberty (CPP); and (2) to determine the clinical predictors of abnormal cranial MRI scans in these patients.

METHODS

A retrospective study of 67 girls diagnosed with CPP who underwent cranial MRI scans at diagnosis. Patients with neurological signs or symptoms at presentation were excluded.

RESULTS

The mean age of onset of puberty was 6.2 years (range 2.0-7.9). Intracranial abnormalities were present in 10 (15%) patients (MR+), while 57 (85%) had no abnormalities (MR-). There was no statistical difference between MR+ patients and MR- patients at presentation with respect to age of onset of puberty, pubertal stage, bone age advance, pelvic ultrasound findings, or height or body mass index standard deviation scores (SDS).

CONCLUSION

Girls with CPP should have a cranial MRI scan as part of their assessment since clinical features, including age, are not helpful in predicting those with underlying pathology. Implementation of such an approach may have a substantial effect on clinical practice and healthcare cost.

Central precocious puberty in girls: an evidence-based diagnosis tree to predict central nervous system abnormalities

OBJECTIVE

To identify predictors of central precocious puberty (CPP) that reveal central nervous system (CNS) abnormalities in girls with CPP.

METHODS

A retrospective cohort study was conducted of all girls younger than 8 years with breast development related to CPP, seen between 1982 and 2000, in a university pediatric hospital in Paris, France. For a pilot population (186 idiopathic, 11 revealing CNS abnormalities), the accuracy of the Lawson Wilkins Pediatric Endocrine Society recommendations were evaluated. Potential clinical, radiological, and biological predictors of CNS abnormalities were assessed by univariate and multivariate analyses. A diagnosis tree aiming for 100% sensitivity for the detection of CNS abnormalities was constructed and was tested on a validation population (39 idiopathic, 3 revealing CNS abnormalities).

RESULTS

Applying the Lawson Wilkins Pediatric Endocrine Society recommendations, 2 of 11 girls with CPP that revealed CNS abnormalities would not have been considered to require brain imaging. Independent predictors of CNS abnormalities were age at onset of puberty <6 years (adjusted odds ratio [AOR]: 6.7; 95% confidence interval [CI]: 1.5-29), lack of pubic hair at diagnosis (AOR: 7.7; 95% CI: 1.8-33), and estradiol >110 pmol/L (AOR: 4.1, 95% CI: 1.0-17). The diagnosis tree that was constructed on the basis of these predictors had 100% sensitivity and 56% specificity for the validation population.

CONCLUSION

The identification of girls who have CPP and require cerebral imaging seems possible on the basis of validated, simple, and reproducible predictors: age and estradiol. However, this process needs to be tested on other populations.

The relationship between magnetic resonance imaging findings and clinical manifestations of hypothalamic hamartoma

OBJECT

Hypothalamic hamartoma is generally diagnosed based on its magnetic resonance (MR) imaging characteristics and the patient's clinical symptoms, but the relationship between the neuroradiological findings and clinical presentation has never been fully investigated. In this retrospective study the authors sought to determine this relationship.

METHODS

The authors classified 11 cases of hypothalamic hamartoma into two categories based on the MR findings. Seven cases were the "parahypothalamic type," in which the hamartoma is only attached to the floor of the third ventricle or suspended from the floor by a peduncle. Four cases were the "intrahypothalamic type," in which the hamartoma involved or was enveloped by the hypothalamus and the tumor distorted the third ventricle. Six patients with the parahypothalamic type exhibited precocious puberty, which was controlled by a luteinizing hormone-releasing hormone analog, and one patient was asymptomatic. No seizures or mental retardation were observed in this group. All patients with the intrahypothalamic type had medically intractable seizures, and precocious puberty was seen in one. Severe mental retardation and behavioral disorders including aggressiveness were seen in two patients. The seizures were controlled in only one patient, in whom stereotactically targeted irradiation of the lesion was performed. This topology/symptom relationship was reconfirmed in a review of 61 reported cases of hamartoma, in which the MR findings were clearly described. The parahypothalamic type is generally associated with precocious puberty but is unaccompanied by seizures or developmental delay, whereas the intrahypothalamic type is generally associated with seizures. Two thirds of patients with the latter experience developmental delays, and half also exhibit precocious puberty.

CONCLUSIONS

Classification of hypothalamic hamartomas into these two categories based on MR findings resulted in a clear correlation between symptoms and the subsequent clinical course.

Reproductive axis after discontinuation of gonadotropin-releasing hormone analog treatment of girls with precocious puberty: long term follow-up comparing girls with hypothalamic hamartoma to those with idiopathic precocious puberty

Although the GnRH agonist analogs have become an established treatment for precocious puberty, there have been few long term studies of reproductive function and general health after discontinuation of therapy. To this end, we compared peak LH and FSH after 100 microg sc GnRH, estradiol, mean ovarian volume (MOV), age of onset and frequency of menses, body mass (BMI), and incidence of neurological and psychiatric problems in 2 groups of girls: those with precocious puberty due to hypothalamic hamartoma (HH; n 18) and those with idiopathic precocious puberty (IPP; n = 32) who had been treated with deslorelin (4-8 microg/kg x day, s.c.) or histrelin (10 microg/kg x day, s.c.) for 3.1-10.3 yr and were observed at 1, 2, 3, and 4-5 yr after discontinuation of treatment. The endocrine findings were also compared to those in 14 normal perimenarcheal girls. There were no differences between the HH and IPP groups in age or bone age at the start of treatment, at the end of treatment, or during GnRH analog therapy. We found that whereas the peak LH level was higher in HH than in IPP girls before (165.5 +/- 129 vs. 97.5 +/- 55.7; P < 0.02) and at the end (6.8 +/- 6.0 vs. 3.9 +/- 1.8 mIU/mL; P < 0.05) of therapy, this difference did not persist at any of the posttherapy time points. LH, FSH, and estradiol rose into the pubertal range by 1 yr posttherapy in both HH and IPP. However, the mean posttherapy peak LH levels in both HH and IPP groups tended to be lower than normal, whereas the peak FSH levels were not different from normal, so that the overall posttherapy LH/FSH ratio was decreased compared to that in the normal girls (HH, 2.7 +/- 0.3; IPP, 2.6 +/- 0.1; normal, 5.2 +/- 4.8; P < 0.05). The MOV was larger in HH than IPP at the end of treatment (3.7 +/- 3.5 vs. 2.0 +/- 1.2 mL; P < 0.05) and tended to increase in both groups over time to become larger than that in normal girls by 4-5 yr posttherapy (HH, 14.9 +/- 12.9; IPP, 7.6 +/- 2.2; normal, 5.4 +/- 2.5 mL; P < 0.05). Whereas the onset of spontaneous menses varied widely in both groups, once menses had started, the HH group had a higher incidence of oligomenorrhea. Pelvic ultrasonography revealed more than 10-mm hypoechoic regions in 4 HH patients, 15 IPP patients, and 3 normal girls, all of whom were reporting regular menses. Live births of normal infants were reported by 2 HH and 2 IPP patients, and elective terminations of pregnancy were reported by 1 HH and 2 IPP patients. BMI was greater than normal in HH and IPP both before treatment and at all posttherapy time points and tended to be higher in the HH patients. Marked obesity (BMI, +2 to +5.2 SD score) was observed in 5 HH and 6 IPP patients, 1 of whom had a BMI of +2.5 SD score and developed acanthosis nigricans, insulin resistance, and hyperglycemia. Seizure disorders developed during GnRH analog therapy in 5 HH and 1 IPP patient, and 2 additional HH girls developed severe depression and emotional lability posttherapy. Although the mean anterior-posterior dimension of the hamartoma was larger in the HH patients with seizure than in those who were seizure free (1.7 +/- 1.2 vs. 0.9 +/- 0.4 cm; P < 0.05), no change in hamartoma size was observed either during or after therapy, and no patient has reported the onset of a seizure disorder posttherapy. Other than a tendency toward a larger MOV, a higher incidence of oligomenorrhea, obesity, and frequency of neurological disorders, recovery of the reproductive axis after GnRH analog therapy was not markedly different in HH compared to IPP. Continued follow-up of these patients may determine whether the decreased LH responses and increased BMI in both groups compared to those in normal girls remain clinically significant problems.

Hypothalamic hamartoma: report of a case with unusual histologic features

A rare case of hypothalamic hamartoma with unusual radiologic and histopathological features is described, possibly the first of its type in English literature. A 1.5-year-old female child presented with precocious puberty. MR scan of the brain revealed a pedunculated hypothalamic mass, most of which was isointense with normal brain on T1- and T2-weighted images. However, a sizeable component of the lesion was hyperintense on T1-weighted images, suggestive of adipose tissue. Microscopically, the lesion was a hamartoma composed of an admixture of neuroectodermal elements, namely glial cells, neurons, and nerve bundles along with mesenchymal elements in the form of fibroadipose tissue.

Gonadotrophin and prolactin secretory dynamics in girls with normal puberty, idiopathic precocious puberty and precocious puberty due to hypothalamic hamartoma

OBJECTIVE

This study was designed to test the hypothesis that hypothalamic hamartoma causes precocious puberty through a different neuroendocrine mechanism than that of normal puberty or of idiopathic precocious puberty.

DESIGN AND PATIENTS

We compared the pattern of gonadotrophin secretion among 4 girls with precocious puberty due to hypothalamic hamartoma, 27 girls with idiopathic precocious puberty, and 14 girls with normal puberty. All subjects were breast stage 3 or 4. Blood samples were obtained every 20 min for 4 h during the day (1.000 hours to 1400 h) and night (22.00 hours to 0200 h).

MEASUREMENTS

LH, FSH, and prolactin were measured in each blood sample. Girls also underwent LHRH-stimulation with measurement of LH and FSH before and after stimulation.

RESULTS

There were no significant differences in mean LH level, LH peak amplitude, or LH or FSH peak frequency during either the day or the night among the three diagnostic groups. However, the mean +/- SD LHRH-stimulated peak LH levels were greater in girls with hypothalamic hamartoma than in girls with normal puberty or with idiopathic precocious puberty (194 +/- 142 vs 85 +/- 60 or 66 +/- 54 IU/l, respectively, P < 0.05). The LHRH-stimulated peak FSH level in girls with hypothalamic hamartoma exceeded the level for the normal pubertal girls (31 +/- 19 vs 17 +/- 7 IU/l, P < 0.05), but not the level for the girls with idiopathic precocious puberty (25 + 12 IU/l). The peak LH to peak FSH ratio in the girls with hypothalamic hamartoma exceeded the ratio for the girls with idiopathic precocious puberty (7.3 +/- 3.9 vs 2.6 +/- 3.0 IU/l, P < 0.05), but not the ratio for the normal pubertal girls (5.0 + 2.9). There were no significant differences in mean prolactin level, peak amplitude or frequency, or in the ratio of mean night to mean day prolactin, among the 3 diagnostic groups.

CONCLUSIONS

We conclude that spontaneous gonadotrophin and prolactin secretion are similar among girls with hypothalamic hamartoma, idiopathic precocious puberty, or normal puberty. However, the increased LHRH-stimulated peak LH in the girls with hypothalamic hamartoma suggests subtle differences in neuroendocrine regulation that may underlie their more rapid pubertal maturation.

Role of surgical resection in the treatment of hypothalamic hamartomas causing precocious puberty. Report of six cases

Hypothalamic hamartomas (HHs) are benign tumors that are often associated with central precocious puberty. Resection of HHs has been recommended as a treatment option for selected cases of pedunculated lesions, especially in young children. The role of surgery has to be evaluated in the light of the availability of effective medical treatment with gonadotropin-releasing hormone analogs (GnRHas). The authors report the long-term results of total resection of HHs in two children with central precocious puberty and compare it with medical management in four children. The two surgically treated patients underwent total resection of pedunculated HHs at 1.75 (Case 1) and 3.25 years (Case 2) and have received follow-up care for 9 and 8 years, respectively. There were no postoperative complications and computerized tomography scanning confirmed complete tumor removal in both patients. Both patients subsequently experienced some regression of secondary sexual characteristics. The response of luteinizing hormone to GnRH became prepubertal in one patient and was diminished in the other. However, the growth velocity remained elevated (> 7 cm/year), bone age remained advanced (> +2 standard deviations) 5 years after surgery, decreasing adult height prediction. In one child, GnRHa therapy was initiated 7 years postsurgery. Four children were treated solely with GnRH agonists and have received follow-up care for 2.3, 6, 9, and 9 years, respectively. These patients have had a complete regression of endocrinological abnormalities, including a normalization of growth velocity and reduction in the rate of skeletal maturation. No side effects were noted with decapeptyl treatment, and one child developed sterile abscesses while receiving Lupron-Depot. The proven efficacy of GnRHa in suppressing puberty and reducing bone age advancement leads the authors to advise against surgery as the initial management of central precocious puberty caused by HHs.

Role of surgical resection in the treatment of hypothalamic hamartomas causing precocious puberty

Hypothalamic hamartomas (HHs) are benign tumors that are often associated with central precocious puberty. Resection of HHs has been recommended as a treatment option for selected cases of pedunculated lesions, especially in young children. The role of surgery has to be evaluated in the light of the availability of effective medical treatment with gonadotropin-releasing hormone analogs (GnRHas). The authors report the long-term results of total resection of HHs in two children with central precocious puberty and compare it with medical management in four children.

The two surgically treated patients underwent total resection of pedunculated HHs at 1.75 (Case 1) and 3.25 years (Case 2) and have received follow-up care for 9 and 8 years, respectively. There were no postoperative complications and computerized tomography scanning confirmed complete tumor removal in both patients. Both patients subsequently experienced some regression of secondary sexual characteristics. The response of luteinizing hormone to GnRH became prepubertal in one patient and was diminished in the other. However, the growth velocity remained elevated (gt 7 cm/year), bone age remained advanced (gt +2 standard deviations) 5 years after surgery, decreasing adult height prediction. In one child, GnRHa therapy was initiated 7 years postsurgery.

Four children were treated solely with GnRH agonists and have received follow-up care for 2.3, 6, 9, and 9 years, respectively. These patients have had a complete regression of endocrinological abnormalities, including a normalization of growth velocity and reduction in the rate of skeletal maturation. No side effects were noted with decapeptyl treatment, and one child developed sterile abscesses while receiving Lupron-Depot.

The proven efficacy of GnRHa in suppressing puberty and reducing bone age advancement leads the authors to advise against surgery as the initial management of central precocious puberty caused by HHs.

New aspects in the diagnosis and treatment of pubertal disorders

Recent developments in biochemistry, genetics, and clinical research have produced a profound effect on the understanding of normal and abnormal puberty. This article is intended to point out selected new developments that affect the understanding of puberty and clinical practice in disorders of puberty.

Salivary gland-like tumors of the sellar region

Herein we present a group of rare tumors of the sella region that have not been previously recognized. Although clinically and radiographically the tumors resemble nonfunctioning pituitary adenomas, their histologic, immunohistochemical, and ultrastructural features differ and indicate a salivary gland origin. The lesions cover a morphologic spectrum that includes cellular pleomorphic adenoma, monomorphic adenoma, oncocytoma, and low-grade adenocarcinoma of the salivary gland. All tumors except the oncocytoma were immunoreactive for cytokeratin and were negative for pituitary hormones and synaptophysin. Ultrastructural characteristics in the cases examined include hypodense stromal material, basal lamina, and tonofilament bundles. The single oncocytoma was packed with mitochondria and lacked membrane-bound secretory granules. DNA ploidy based on image analysis and MIB-1 labeling indices showed diversity within this group of tumors, with labeling indices ranging from 0.06% to 15%. The presumed origin of these rare neoplasms is from salivary gland rests related to the normal pituitary gland. Despite their varied morphology, such tumors are easily confused with pituitary adenoma. Although rare, tumors of salivary gland origin should be considered in the differential diagnosis of unusual adenohypophyseal tumors.

Targeting transforming growth factor alpha expression to discrete loci of the neuroendocrine brain induces female sexual precocity

Precocious puberty of cerebral origin is a poorly understood disorder of human sexual development, brought about by the premature activation of those neurons that produce luteinizing hormone-releasing hormone (LHRH), the neuropeptide controlling sexual maturation. An increased production of transforming growth factor alpha (TGF alpha) in the hypothalamus has been implicated in the mechanism underlying both normal and precocious puberty. We have now used two gene delivery systems to target TGF alpha overexpression near LHRH neurons in immature female rats. Fibroblasts infected with a retroviral construct in which expression of the human TGF alpha gene is constitutively driven by the phosphoglycerate kinase promoter, or transfected with a plasmid in which TGF alpha expression is controlled by an inducible metallothionein promoter, were transplanted into several regions of the hypothalamus. When the cells were in contact with LHRH nerve terminals or in the vicinity of LHRH perikarya, sexual maturation was accelerated. These results suggest that precocious puberty of cerebral origin may result from a focal disorder of TGF alpha production within the confines of the LHRH neuron microenvironment.

Precocious puberty

Puberty occurring before the age of 8 years in girls and 9 years in boys in considered precocious. The numerous causes of precocity can be classified as central or peripheral. Central or true precocious puberty (CPP) is due to premature activation of the hypothalamopituitary-gonadal axis and is isosexual. Peripheral or pseudoprecocious puberty (PPP) results from the production of sex steroids independent of the H-P-G axis and may be isosexual or heterosexual. CPP is the most common form of precocity involving more than 50% of children and is much more common in girls than boys. CPP is more common between 4 and 8 years. A peak serum LH levels > 10 iu/l following GnRH stimulation is the absolute evidence of CPP. Serum IGF-I levels are predictive of the outcome. Availability of CT and MRI has helped to determine the cause of CPP in most cases. Hypothalamic hamartoma is the most common tumour causing CPP especially in boys. Adrenal causes, particularly CAH, are the commonest cause of PPP in boys whereas ovarian causes are more likely in girls. Long acting GnRH analogues provide a safe and effective form of treatment of CPP.

Differentiating neuroblastoma of pituitary gland: neuroblastic transformation of epithelial adenoma cells. Case report

The authors report the case of a 40-year-old woman with a 12-year history of irregular menses, amenorrhea, infertility, galactorrhea, a slightly elevated prolactin level, and a slowly growing pituitary adenoma. She developed recent onset of visual symptoms, prompting craniotomy for removal of an intrasellar tumor. Following surgery, her vision and prolactin levels returned to normal. Light microscopic and immunohistochemical examination of the tumor revealed it to be a neuroblastoma, which was immunohistochemically positive for synaptophysin, S-100 protein, and oxytocin. The neoplasm contained prolactin-positive neuroblastic and pituitary epithelial cells. No other pituitary hormones were found. Electron microscopy demonstrated two cell types: one with frequent neuritic processes containing neurosecretory granules and showing synaptic specialization, and another one compatible with epithelial adenohypophyseal cells. A few cells had ultrastructural features that were transitional between neuronal cells and granulated epithelial cells. Agranular folliculostellate cells were also identified. Immunoelectron microscopy demonstrated prolactin granules in the cytoplasm of the epithelial cells, in a few transitional cells, and in scattered neuritic processes. Ultrastructural and immunohistochemical features of the tumor suggested a transformation of pituitary epithelium to neuroblastic cells. Hyperprolactinemia and associated clinical symptoms may in part be attributed to selective prolactin secretion by neoplastic cells that were differentiating into adenomatous pituitary cells and, to a lesser extent, to cells differentiating into a neuroblastic line. Compression of pituitary stalk might also have been a contributory factor to the increased prolactin levels. Moreover, the oxytocin produced by the neuroblastic cells was considered an additional stimulus for prolactin secretion by neoplastic cells or by the normal pituitary.

[Precocious puberty and hypothalamic hamartoma: treatment with triptorelin during eight years]

BACKGROUND

Hypothalamic hamartoma, a rare cause of true sexual precocity, may develop slowly so that its diagnosis may be late.

CASE REPORT

A 7 1/2-month-old girl was admitted because she suffered from development of physical pubertal changes. Laboratory tests were consistent with premature activation of the hypothalamic-pituitary axis. Initial neuroradiological investigation failed to find any cause. The patient was given medroxyprogesterone that resulted in regression of secondary sexual characteristics but growth rates and skeletal maturity remained accelerated. For that reason, the patient was given triptorexine, LH-RH analogue, 18 months later that resulted in a deceleration of puberty growth rate and skeletal maturity. MRI performed at the age of 9 years showed a small hypothalamic hamartoma and the LH-RH analogue was stopped at the age of 10 years.

CONCLUSION

MRI is now the best technique for investigating the hypothalamo-hypophyseal area.

A super long-acting LH-RH analogue induces regression of hypothalamic hamartoma associated with precocious puberty

We treated a 1-year-old female with a hypothalamic hamartoma and precocious puberty with leuprolide acetate depot, a super long-acting hormone-releasing hormone analogue (Tap-144-SR; [D-Leu6-[des-Gly10-NH2] LH-RH ethylamide acetate). The infant's major symptoms were genital bleeding and gynaecomastia. The LH-RH analogue (30 micrograms/kg) was injected subcutaneously once every 4 weeks. Clinical and laboratory manifestations of precocious puberty showed marked improvement. A follow-up after 16 months of treatment, the size of the tumour decreased significantly and remained unchanged for 2 years of further follow-up. To the best of our knowledge, this is the first hypothalamic hamartoma case in whom a decrease of tumour size under treatment with LH-RH analogue has been documented. But, because diagnosis of hamartoma is only based on neuroradiological and not on histological examinations, the possibility of a gangliocytoma cannot be excluded with certainty.

Cerebral and cerebellar gangliocytomas: a morphological study of nine cases

Hypothalamic gangliocytomas have been shown to contain immunoreactivity for hypophysiotropic peptides and some have been associated with endocrine dysfunction. Extrahypothalamic gangliocytomas are usually not associated with endocrine abnormalities. We studied nine cerebral or cerebellar gangliocytomas from six men and three women; none of the patients had detectable alterations of endocrine homeostasis. On histological examination, the tumor cells resembled hypothalamic neurons. Electron microscopy disclosed the presence of dense-core vesicles in neuronal cytoplasm and processes resembling Herring bodies, and there were synaptic contacts between tumor cells. All but two tumors contained immunocytochemical positivity for at least one peptide hormone or amine; these included somatostatin, corticotropin-releasing hormone, beta-endorphin, galanin, vasoactive intestinal peptide, calcitonin, serotonin, catecholamines or met-enkephalin. These tumors have been thought to represent neoplasms arising in ectopic autonomic neural tissue. Their morphological features, their similarity to hypothalamic gangliocytomas and the multiple immunoreactivities shown here suggest that they can be regarded as tumors of peptidergic neurons that are widely distributed throughout the central nervous system.

Hypothalamic hamartomas: with special reference to gelastic epilepsy and surgery

This study presents six patients with hypothalamic hamartomas diagnosed on the basis of magnetic resonance imaging. Histological confirmation was performed in three patients who underwent surgery. Immunohistological assays were used to determine the neurosecretory pattern. Four patients presented with epilepsy, including gelastic seizures. Other symptoms included behavioral abnormalities in four patients and precocious puberty and visual impairment in two patients. One patient presented associated developmental defects. Good results without morbidity were achieved with surgical resectioning in two patients with large hamartomas associated with behavioral abnormalities and gelastic epilepsy that was unresponsive to conventional medical treatment and in one patient with visual impairment. We propose a classification of the hypothalamic hamartomas based on topographical and clinical data obtained from 36 selected cases in the literature and six of our own cases. This classification should help to classify the various treatment methods and the surgical risks into four subgroups (Types la, lb, lla, and llb). We conclude that the surgical approach is a realistic alternative in certain cases, including large and broad-based Type llb hamartomas associated with gelastic epilepsy and behavioral disorders.

Hypothalamic hamartoma in oral-facial-digital syndrome type VI (Váradi syndrome)

Oral-facial-digital syndrome (OFDS) type VI (Váradi syndrome) is an autosomal recessive trait of orofacial anomalies, cerebellar dysgenesis, and polysyndactyly. Developmental anomalies of the posterior fossa, including cerebellar hypoplasia and variants of the Dandy-Walker complex, are the most common central nervous system malformations reported in patients with this syndrome. We report hypothalamic hamartoma, supernumerary maxillary incisor, and precocious puberty in a boy with OFDS type VI. We propose that hypothalamic hamartoma is an occasional manifestation of OFDS type VI.