The intracranial lipomas are rare congenital malformations accounting for approximately 0.1-1.3% of all intracranial tumors, of which Sylvian fissure lipomas account for <5%. These lesions are frequently associated with dysgenesis of neuronal brain tissues and vascular malformations and in the majority are asymptomatic. Intracranial lipomas on magnetic resonance imaging (MRI) may mimic late subacute hemorrhage due to similar radiological features. Due to the tight adhesion of the lipoma to the surrounding nerve structures and vessels, complete removal is difficult and does not guarantee the disappearance of symptoms.

We present the case of a 42-year-old woman with chronic headaches and short-term memory impairment who was admitted to the emergency room after an out-of-hospital brain MRI with suspected ruptured right middle cerebral artery (MCA) aneurysm and late subacute intracranial hemorrhage. In the hospital, after clinical evaluation, emergency computed tomography (CT) angiography was performed, which revealed an unruptured fusiform aneurysm located in the right MCA trifurcation surrounded by an extremely hypodense lesion corresponding to fat in the right Sylvian fissure. No features of intracranial hemorrhage were present. The diagnosis of intracranial lipoma was finally confirmed after the MRI of the brain with a fat suppression sequence. Surgical treatment was not attempted, and the patient was treated conservatively with a satisfactory general outcome.

A Sylvian fissure lipoma may be associated with a fusiform aneurysm in the MCA trifurcation. By modifying the standard MRI protocol and performing a CT scan, an intracranial lipoma can be detected and a late subacute intracranial hemorrhage can be excluded.

Intracranial lipomas account for less than 1% of all brain tumors. Corpus callosum lipoma (CCL) is a rare finding and up until now, documented cases are around 200 patients. These lipomas remain mostly asymptomatic, but when symptoms appear, they present through headache, seizure, dementia and in some cases, rather uncommon neurological disorders such as mirror writing. Fourteen years old girl with history of 8 years headache and recent development of vertigo, extremities trembling and drop attack was referred to neurologist and brain imaging confirmed CCL. Herein, we report another rare case of CCL, with common and uncommon symptoms of latter tumor in detail; in addition to reviewing the previous 80 years case reports aiming to achieve comprehensive perception from CCL. Keywords: Lipoma, Corpus callosum, Brain tumors.

Intracranial lipomas are rare congenital lesions that occur because of abnormal differentiation of embryogenic meninges. These lipomas are usually seen incidentally on brain imaging, and are usually asymptomatic and do not require treatment. The authors present a case of ruptured intracranial lipoma, discovered in an elderly patient presenting with dizziness and episodes of falls.

Intracranial lipomas are thought to be congenital in origin and are very rare, representing 0.1% to 1.7% of all intracranial tumors. Most ICLs are located at midline. Lipomas at sylvian fissure are extremely rare. They are slow growing, and biological course is favorable even without surgical treatment. A Medline search of the literature from 1965 to 2007 revealed only 13 cases of sylvian fissure lipomas reported. Of 9 patients with sylvian fissure lipoma diagnosed during life, 6 patients were operated on with no mortality and got improvement of symptoms. Surgical intervention should be considered if there are problems such as compressive effect or resistance to anticonvulsive medical treatment.

We report a 57-year-old woman with a sylvian fissure lipoma presenting with persistent intractable headache. Imaging study showed a lobular nonenhanced lesion associated with abnormal vessels in the right sylvian fissure. The patient underwent minimally invasive pterion keyhole approach, and the lipoma was successfully and totally removed. Headache and subsided postoperatively.

There are only few cases of sylvian fissure lipomas in which surgical excision has been attempted. Because of improvement of microsurgical techniques, direct surgical approach with total removal of lipomas, via a minimally invasive pterion keyhole approach, is feasible. Therefore, it should be kept in mind that the primary goal of the surgery is adequate decompression; and total removal may be achieved if the lesion permits.

Despite the lipomas are the tumors that more commonly occur in the corpus callosum (CC), its incidence in the population is not common. We report on a 5-year old boy, with history of retardation in the psychomotor development and disturbs in the gait, secondary to generalized hypotony. Magnetic resonance imaging showed a curvilinear lipoma of the CC related to its hypertrophy. In the literature patients with CC lipoma usually have agenesis or hypotrophy of the CC, but in the reported case we have seen, by the first time, a hypertrophy of the CC. We made embryologic, genetic, clinical, radiographic and therapeutic considerations about the patients that have CC lipoma comparing to findings in the case we report.

Three children with complete or partial callosal aplasia and intracranial lipoma in the corpus callosum region were investigated. Two lipomas were tubulonodular; one replaced the entire corpus callosum structure. Accompanying anomalies affected the cingulate gyrus, septum pellucidum, and choroid plexus. In one case, diagnosis was made in utero in the 25th gestational week by ultrasonography; in the second case it was made on the first day of life, also by screening ultrasonography. Two children had mild spastic distal diparesis; one complained of chronic headache. Electroencephalography showed no abnormalities; epilepsy anamnesis was negative. Somatosensory and visual evoked potentials showed prolonged conduction in two cases. Surgery was not indicated. Because of the risk of developing epileptic seizures, regular electroencephalographic follow-up investigations are essential.

A case of intracranial lipoma located in the interpeduncular fossa of a young woman is presented. Since the patient suffers only nonspecific headache, no treatment was performed. To our knowledge this is the only which was demonstrated by magnetic resonance images (MRI) in the English language literature.

The agenesis and lipoma of the corpus callosum is a very rare association. We report the case of a 18-years old woman with rare epileptic seizures since the age of 6 years, normal neurological examination, as well as normal electroencephalogram. The brain computed tomography scanning and the magnetic resonance showed the lipoma and the agenesis of the corpus callosum.

A case of symptomless, solitary lipoma of the choroid plexus is described. The tumour was found in the left lateral ventricle of an adult female baboon (Papio papio) in the course of post-mortem examination. Routine histological investigation showed that the tumour was composed exclusively of characteristic adipose cells with scarce collagen septa and without other hamartoma-like constituents, such as glial cells, neurons, cartilage or muscle fibres. The tumour mass was lined by a typical single layer of cuboidal cells; no calcifications were observed either inside the tumour or in the adjacent periventricular regions. This case is reported in view of the rarity of such tumours of the choroid plexus in man and animals, and to throw light on their possible origin.

A 4-year-old Japanese boy with an intracranial lipoma above the surface of the left centroparietal lobes is reported. Paresthesia occurred in the right lower extremity. This symptom continued for 30 min and recurred several times a day. Three weeks after onset, the paresthesia disappeared spontaneously. Ten months after onset, generalized tonic seizures occurred. Routine cranial computed tomography at onset revealed no remarkable lesion, but subsequently full scans, including the slice at the top of the cerebrum, revealed low-density areas on the surface of the left centroparietal lobes. T1-weighted magnetic resonance imaging revealed a hyperintense area in the same regions. The intensity of these areas was decreased by the fat saturation technique; therefore, an intracranial lipoma at a very rare site was diagnosed.

Intracranial lipomas are very rare lesions, which are probably congenital. Though they can occur anywhere in the intracranial space, a high proportion of cases tend to be ++located around the midline. They are usually asymptomatic. When symptoms do occur, they are frequently the result of co-existing general clinical conditions. Lipomas used to be reported mainly as incidental findings at autopsy, but advances in neuroimaging techniques have greatly improved the likelihood of their being discovered during life. Surgical extirpation is not necessary in the majority of patients, many of whom show remarkable clinical improvement following shunt procedures for obstructive hydrocephalus (when present) as well as vigorous treatment of co-existing conditions.

Intracranial lipomas are very rare, probably congenital lesions. Though they can occur anywhere in the intracranial space, a good proportion of cases tend to be located around the midline. Review of the literature as well as our own three cases--which forms the basis of this article--shows that they are mostly asymptomatic. When symptoms occur, they are frequently the result of coexisting general clinical conditions. Lipomas used to be reported mainly as incidental findings at autopsy. Advances in neuro-imaging techniques have vastly improved the likelihood of their being discovered during life. At present however, significant increase in the reported incidence of these tumours is yet to be seen. Surgical extirpation of the tumour is not considered necessary in the majority of patients, many of whom show remarkable clinical improvement following shunt procedures for obstructive hydrocephalus as well as treatment of coexisting conditions such as epilepsy.

Computed tomographic and plain X-ray observations in a patient with corpus callosum lipoma associated with frontal encephalocele are reported. The rarity of the lesion and the specific diagnostic criteria on CT are emphasised.

An exceptional case of lipoma of the sylvian region is described and the other seven reported cases are reviewed. The sylvian fissure is the most rare site of intracranial lipomas. Sylvian lipomas may be asymptomatic or present with epileptic seizures due to irritation of the cortex of the sylvian fissure. Only two previous cases have been diagnosed during life by computerized tomography and operated on; the deep location of these lipomas and their adherences to the sylvian cortex and the branches of the middle cerebral artery make radical removal impossible and dangerous.

A lipoma of the corpus callosum in an infant is evaluated by ultrasound and magnetic resonance. The appearances are correlated as a diffuse but continuous aspect of this midline anomaly.

Seven hundred five cases of agenesis of the corpus callosum (ACC) are reviewed from the literature (n = 660) and from our own observations (n = 45). The diagnosis was made or confirmed using neuroradiological techniques (n = 519) and necropsy or surgery (n = 231). Association with abnormalities often of chromosomes 8, 11, 13-15 and 18 suggests their involvement in abnormal corpus callosum (CC) morphogenesis. Four syndromes (e.g. Aicardi, acrocallosal, Andermann and Shapiro) are characterized by ACC, while others are only sporadically associated (e.g. fetal alcohol syndrome, Dandy-Walker syndrome, Leigh disease, Arnold-Chiari II syndrome). In non-Aicardi patients, the male-to-female ratio was 3:2 and X-linked recessive inheritance is postulated to play a role in some cases. Common abnormalities in acallosal patients included: mental retardation (MR), 73% [corrected]; seizures, 42%; ocular anomalies, 42%; gyral abnormalities, 32%; hydrocephalus, 23%; other central nervous system (CNS) lesions, 29%; costovertebral defects, 24%. Developmental disabilities are not attributable to absence of the CC per se, but due to other CNS malformation or dysfunction, which may be genetic or non-genetic. Future research using recombinant DNA techniques will enable isolation and identification of specific chromosomal defects in those cases with a genetic abnormality.

Lipoma of corpus callosum and choroid plexus lipoma are rare developmental anomalies arising as a result of maldifferentiation of primitive meningeal tissue. Two cases are reported along with a brief review of literature. The first case presented with chronic headache, and a large lipoma of corpus callosum associated with choroid plexus lipoma was discovered. The second case had no symptoms before the discovery of corpus callosal lipoma on computed tomography, which was done for a head injury. None of the lipomas showed any calcification.

A longitudinal study was performed of eight patients with fronto-nasal dysplasia. The follow-up exceeded 15 years in some patients. The eight cases showed lipoma of the corpus callosum. The only clinical alterations observed were cosmetic ones. No neurological abnormality was found, although their intellectual level was just within normal limits, the average IQ being 95, ranging from 82-103. No relationship between the IQ and the type of facies or the size of the lipoma was found. All the children presented psychological alterations, especially misanthropy and shyness. The lipoma was diagnosed by computerised tomography. Two otherwise unidentifiable small lipomas were found with this technique. Pneumoence-phalography and carotid arteriography, which had been performed on nearly all the patients before CT scanning, had demonstrated some alterations. These anomalies slightly deformed the anterior portion of the lateral ventricles and anterior cerebral arteries, but a lipoma in the corpus callosum had not been considered. Only in one case was hypogenesis of the corpus callosum clearly demonstrated. The presence of an extra-osseous lipoma on the forehead and of a vertical bony bar in the intracranial midline in contact with the frontal bone are definite signs of the presence of a lipoma in the corpus callosum. The lipoma is in anterior contact with the vertical bony bar. The neurological alterations presented by the patients in this series are minor compared with those described by other authors writing of children with lipoma of the corpus callosum without FND. Because of mild clinical alteration in these children we have not considered removing the lipoma.

This report concerns a case of lipomas in the corpus callosum, possibly both lateral ventricles, and the forehead, which were associated with a defect in the frontal bone. It is thought that the lipoma originated in the interhemispheric fissure and extended to the forehead by at least the second month of gestation. It interfered with the development of the corpus callosum, and the collagenous capsule of the lipoma remained till birth. It caused a defect in the frontal bone in the midline, in spite of the development of both frontal bones.

Cephaloceles are congenital malformations with herniation of intracranial structures through a defect in the cranium. On the basis of a review of the literature and 31 personal observations the authors discuss the clinical and neuroradiological presentation of their various anatomical locations: sphenoidal, ethmoidal, frontal, occipital and parietal.

Lipoma of the corpus callosum is a rare intracranial condition, possibly congenital. It is often asymptomatic, but may present with headaches, seizures, hemiplegia, or dementia. An example of this disease is reported, and the condition reviewed. The radiological appearance is described, with emphasis on the value of computerized tomography in making the diagnosis. Surgery is of limited value but may be required in specially selected cases.

A patient with spontaneous periodic hypothermia who had both a lipoma and agenesis of the corpus callosum is described. Spontaneous periodic hypothermia associated with corpus callosum abnormalities is a distinct entity and although the mechanism underlying the hypothermic episodes is unexplained, the term "diencephalic autonomic epilepsy" does not seem appropriate.

The value of CT in the easy diagnosis of lipomas and associated anomalies of the corpus callosum, thus avoiding angiography and pneumoencephalography, is reported in five cases. An angiogram was performed in only one of the five cases and provided no additional diagnostic information.

Eleven cases of intracranial lipoma, diagnosed during life by computerized tomography (CT) scanning, are presented. Clinical symptoms related to the lesions were present in eight. The CT scan established the diagnosis of intracranial lipoma on the basis of typical x-ray absorption and location. Only dermoid cysts and teratomas may produce a similar CT appearance. In cases of intracranial lipoma, a direct surgical approach is seldom necessary, although in certain locations, lipomas may cause blockage of cerebrospinal fluid pathways and require a shunt operation.

A case is reported in which systemic Weber-Christian disease presented as a dural mass causing the signs and symptoms of increased intracranial pressure. The literature and possible pathogenesis of this entity are discussed.