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

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.

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.

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.

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.