Asymptomatic hypothalamic hamartoma associated with an arachnoid cyst--case report

Infantile Hypothalamic Hamartoma: A Rare Presentation of Isolated Obesity

Hypothalamic hamartomas (HHs) are rare, benign brain tumors or lesions of the hypothalamus that are predominantly identified in cases of epilepsy and central precocious puberty (CPP), whereas isolated manifestations of infantile obesity are atypical. We herein report an 8-month-old boy with severe obesity (Kaup index 26.4 [>100th percentile]) and uncontrollable hyperphagia. His growth chart demonstrated remarkable weight gain that exceeded the length gain in magnitude. Brain magnetic resonance imaging identified a lesion consistent with HH. There were no episodes or clinical findings of epilepsy, CPP, or Cushing disease. Hypothalamic obesity should be considered in the diagnosis even in infants with excessive weight gain due to overeating.

Interpeduncular Heterotopia and Brain Stem Cleft: An Isolated Finding Not Associated with Joubert Syndrome

Interpeduncular heterotopia is a new neuroimaging finding reported in association with Joubert syndrome (JS) in a few cases in the literature. Nodular interpeduncular tissue was termed as interpeduncular heterotopia and anterior mesencephalic cap dysplasia in the literature in relation to gray and white matter content. We described the imaging findings and diffusion tensor imaging data of a case with interpeduncular heterotopia and brain stem cleft. This is the first case, in which interpeduncular heterotopia was an isolated finding not associated with JS.

Pre- and postnatal MR imaging of an asymptomatic giant hypothalamic hamartoma

Hypothalamic hamartomas are rare tumors that are most often diagnosed in early childhood. These lesions are classified as giant hypothalamic hamartomas when they exceed 4 cm in any 1 dimension. The most common presenting symptoms associated with these lesions are precocious puberty, gelastic seizures, and (less commonly) syndromic conditions such as Pallister-Hall syndrome. We present a unique case of an asymptomatic giant hypothalamic hamartoma diagnosed prenatally by fetal magnetic resonance imaging and followed throughout infancy. This case demonstrates the utility of multimetric analysis using difference sequences, including diffuse-weighted imaging, to assess specific properties of intracranial lesions detected in utero and to aid in accurate diagnosis prior to birth.

Giant hypothalamic hamartoma associated with an intracranial cyst in a newborn

We report the case of a giant hypothalamic hamartoma with a large intracranial cyst in a neonate. On ultrasonography, the lesion presented as a lobulated, mass-like lesion with similar echogenicity to the adjacent brain parenchyma, located anterior to the underdeveloped and compressed left temporal lobe, and presenting as an intracranial cyst in the left cerebral convexity without definite internal echogenicity or septa. The presence of a hypothalamic hamartoma and intracranial neurenteric cyst were confirmed by surgical biopsy. The association of a giant hypothalamic hamartoma and a neurenteric cyst is rare. Due to the rarity of this association, the large size of the intracranial cyst, and the resulting distortion in the regional anatomy, the diagnosis of the solid mass was not made correctly on prenatal high-resolution ultrasonography.

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.

Suprasellar hamartoma and arachnoid cyst

OBJECTIVE

The differential diagnosis for suprasellar masses includes a variety of pathologies, ranging from stable and benign lesions to aggressive and malignant ones. We report a case of a suprasellar hamartoma associated with an arachnoid cyst and review the literature surrounding the topic.

CASE DESCRIPTION

A 32-year-old man who presented with headaches and nonspecific vision loss was found to have a cystic, calcified, and minimally contrast enhancing lesion of the suprasellar region. Intraoperative inspection revealed a discrete mass in the right side of suprasellar region that resembled normal brain completely enveloped by the basal arachnoid membranes including the membrane of Lillequist and was not connected to the brain. Fenestration and exploration of the cystic portion demonstrated a simple arachnoid cyst filled with what appeared to be cerebrospinal fluid. Given the adherence of the lesion to numerous perforating arteries arising from the posterior communicating artery, a biopsy with intraoperative confirmation was taken. Pathology was consistent with neuroglial tissue without evidence of neoplasia.

CONCLUSIONS

To our knowledge this is only the third case of an isolated suprasellar hamartoma described in the literature and the first of its kind to be associated with an arachnoid cyst.

Interpeduncular heterotopia in Joubert syndrome: a previously undescribed MR finding

The so-called molar tooth sign is the radiologic hallmark of JSRD. Joubert syndrome is a rare, most often autosomal-recessive disorder with a characteristic malformation of the midhindbrain. We describe 3 patients with JSRD and the additional MR finding of tissue resembling heterotopia in the interpeduncular fossa, which in one patient was combined with a more extensive intramesencephalic heterotopia. Interpeduncular heterotopia has not been reported previously, either in the context of JSRD or as a separate entity. This new imaging feature enlarges the spectrum of brain stem abnormalities in JSRD. In view of the underlying ciliopathy, it seems likely that the interpeduncular heterotopia results from misdirected migration.

Synchronous occurrence of a hemorrhagic hypothalamic hamartoma and a suprasellar teratoma

Hypothalamic hamartomas have been reported to coexist with lesions like Rathke's cleft cyst and arachnoid cysts in the suprasellar or temporo-sylvian regions. This is the first report in indexed literature describing its association with a suprasellar teratoma. A 7-year-old girl presented with long-standing precocious puberty and generalized tonic-clonic seizures and recent-onset raised intracranial pressure. MRI done prior to the onset of symptomatic raised intracranial pressure revealed 2 distinct lesions in the suprasellar region. One was a midline, pedunculated lesion arising from the hypothalamus, with evidence of an old bleed within it. A separate lesion, with a wide base near the tuberculum sellae and a posteriorly directed conical tip, was noted in an adjacent sagittal cut. CT scan done at the time of admission demonstrated a re-bleed in the suprasellar region with blood in the lateral and third ventricles and gross hydrocephalus. The child was taken up for a ventriculoperitoneal shunt followed by complete excision of the lesions. Histopathologic examination confirmed the pedunculated lesion to be a hypothalamic hamartoma with evidence of hemorrhage, and the other to be a mature teratoma. Postoperative MRI confirmed complete excision of both the lesions. The child reported regression of precocious puberty and remained seizure-free until the last follow-up 6 months after surgery. A hypothesis based on a dysontogenetic mechanism is discussed to explain the unusual occurrence of the dual, seemingly unrelated pathologies. Hemorrhage into the hamartoma was an added oddity in this case.

Reassessment of holoprosencephaly–diencephalic hamartoblastoma (HDH) association

We report on a 23-week fetus with a hypothalamic hamartoma, lobar holoprosencephaly, right anophthalmia, and facial asymmetry, features which are consistent with the holoprosencephaly-diencephalic hamartoblastoma (HDH) association. In an attempt to better delineate HDH, we reviewed 19 published patients with similar features. The HDH clinical spectrum ranges from classic holoprosencephaly with micro/anophthalmia, multiple additional findings in non-contiguous structures and early lethality, to isolated microforms of holoprosencephaly. Associated cephalic features mainly include cortical/neuronal migration defects (39%), meningeal anomalies (28%), brainstem/posterior fossa malformations (22%), dysmorphic ears (41%), facial asymmetry (35%), and hypoplastic mandible (29%). Fifty-three percent of patients have additional extra-cephalic malformations, for example, vertebral/rib segmentation defects (50%), hypo/aplastic lungs (38%), congenital heart defect (29%), and urinary anomalies (29%). HDH shows etiological heterogeneity, that is, teratogenic exposure, chromosome imbalances, autosomal recessive as well as dominant "de novo" mutations. Several features could directly result from a disruptive sequence caused by an early hamartoma which alters the development of forebrain, hindbrain, meninges, and 1st-2nd branchial arches, although the pleiotropic action of genetic/environmental factors cannot be excluded. HDH does not emerge as a distinct syndrome, but other hypotheses, including separate conditions within a common pathway and the developmental field defect theory, are discussed.

Hypothalamic hamartoma in association with a suprasellar arachnoid cyst: a case report

A 5-year-old female presented with a history of precocious puberty and increased height. MRI of the brain revealed a nonenhancing hypothalamic mass and associated suprasellar arachnoid cyst. The patient underwent a right frontal craniotomy with orbital osteotomy for wide fenestration of the cyst. Intraoperatively, it was clear the mass represented a hamartoma with a very smooth glistening surface. For this reason, no biopsy of the wall was performed. Postoperatively, the patient remains neurologically intact and without any medication dependence. This case highlights the occurrence of a suprasellar arachnoid cyst in association with a hypothalamic hamartoma.

Suprasellar arachnoidal cyst as a cause of precocious puberty--report of three patients and literature overview

The authors present three boys--3 years old, 5.8 years old and 10.4 years old--who were diagnosed with isosexual precocious puberty (IPP) triggered by a rare developmental disorder of suprasellar arachnoid cyst (SAC) accompanied by corpus callosum and fornix dysgenesis as well as anterior commissura magna agenesis (patient 1) and empty sella (patients 2, 3). The reason for diagnostic management recommendation was a rapid progression of IPP signs over one year (patients 1, 2) or 6 months (patient 3) prior to hospitalization, these signs having been present but less intense since infancy (patient 1), 4th year of life (patient 2) and approximately 8 years of age (patient 3). Neurological signs (spastic paresis in patient 1, postural tremor in patient 2 and head bobbing and behavioral changes in patient 3), as well as slowly progressing increased head circumference were observed since neonatal period (patient 1), 1 year old (patient 2) and approximately 4 years old (patient 3). None of the patients manifested hypophyseal-hypothalamic axis dysfunction other than IPP prior to and after surgical management. Shunt implantation resulted in gradual resolution of neurological signs in all patients and in patient 3 also in partial normalization of serum testosterone levels and growth rate. Regression of IPP in patients 1 and 2 was achieved by administration of a long-acting GnRH analogue. Our observations are in accord with data reported by other investigators and confirm the often slow, insidious development of subsequent SAC signs, the type and intensity of which differ from patient to patient. We suggest that some of the neuroanatomical anomalies coexisting with SAC may have a common genesis, or they could under certain conditions be an additional trigger for IPP and possibly other hypothalamopituitary dysfunction.

Hypothalamic hamartoma associated with an arachnoid cyst

A hypothalamic hamartoma associated with an arachnoid cyst in an 8-year-old boy is reported herein. He presented with precocious puberty, and neuroimaging studies demonstrated a solid mass in the prepontine cistern and a huge arachnoid cyst in the left cranial fossa. The mass appeared isointense to the surrounding cerebral cortex on T1-weighted magnetic resonance images, hyperintense on T2-weighted images, and was not enhanced after administration of Gd-DTPA. The patient underwent a left frontotemporal craniotomy and a cyst-peritoneal shunt was inserted. Histological features of the cyst wall and the mass were characteristic of an arachnoid cyst and hamartoma, respectively. While a hypothalamic hamartoma associated with an arachnoid cyst is rare, such a case may help clarify the geneses of both anomalous lesions.

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.