Intracranial lipoma. Diagnostic and therapeutic considerations

Anomalies of the Mesenchyme (Meninges and Skull)—Defects of Neural Tube Closure: Cephalocele and Other Calvarial and Skull Base Defects; Intracranial Lipomas; Arachnoid Cysts; Nonsyndromic and Syndromic Craniosynostoses

Within the embryonic head, a layer of mesenchyme envelops the brain beneath the surface ectoderm. This cranial mesenchyme is responsible for the formation of the meninges, the calvaria (upper portion of the skull), and the scalp's dermis. Irregular development of these structures, particularly the meninges and the calvaria, is associated with notable congenital defects in humans, such as defects in neural tube closure. Anencephaly is the most common neural tube defect (NTD) and one of the most severe malformations of the central nervous system; it consists in the complete or partial absence of the brain, associated with the absence of the bones of the cranial vault. Iniencephaly is an uncommon congenital NTD characterized by abnormalities in the occipital region, including rachischisis of the cervicothoracic spine and a fixed retroflexion deformity of the head. Unlike anencephaly, in iniencephaly, there is a skull cavity and a normal-looking skin that entirely covers the head and the medullary retroflex area. Cephaloceles are congenital abnormalities distinguished by the protrusion of meninges and/or brain tissue through a naturally occurring defect in the skull bone. This anomaly is typically covered by skin or mucous membrane. Intracranial lipoma is a relatively uncommon and generally benign tumor that occurs in an abnormal location within the brain; it probably represents a disturbance of the differentiation of the primordial meninges: for unknown causes, the meningeal mesenchyme can differentiate into adipose tissue. Arachnoid cysts are sacs filled with cerebrospinal fluid (CSF) situated between the brain or spinal cord and the arachnoid membrane. Typically, these cysts originate within CSF cisterns and gradually expand their boundaries. Craniosynostosis is the early fusion of one or more cranial sutures. It can occur spontaneously, be associated with a syndrome, or have a familial connection. It can involve one or multiple cranial sutures. Pfeiffer's, Crouzon's, and Apert's syndromes are among the more prevalent syndromic craniosynostoses.

Sylvian fissure lipoma associated with fusiform aneurysm in the middle cerebral artery trifurcation: A case report and literature review

BACKGROUND

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.

CASE DESCRIPTION

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.

CONCLUSION

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.

Frontal subcutaneous lipoma associated with large interhemispheric lipoma and corpus callosum agenesis

Intracranial lipomas are extremely rare fat-containing lesions that comprise 0.1%-0.5% of all primary brain tumors. They are congenital lesions that arise due to persistence and maldifferentiation of the meninx primitive (subarachnoid space precursor). We report a case of a 30-year-old woman who presented with seizures due to an intracranial lipoma and no neurological deficits. CT (computerized tomography) imaging findings demonstrated a large interhemispheric partially calcified lipoma that communicated with a large scalp lipoma and was associated with agenesis of the corpus callosum. Compared to the prior CT imaging, the lipoma increased in size from 3.4 cm to 4.1 cm transversely. A recent CT angiogram done due to suspicion of an aneurysm showed the lipoma now measuring 6 cm by 4.7 cm. Most cases of intracranial lipoma have been reported in the pediatric age group. Here, we report a rare case of interhemispheric intracranial lipoma in the adult age group. This case also demonstrates the importance of imaging modalities for detecting intracranial lipoma without performing invasive brain biopsy.

Evaluating the utility of a scoring system for lipomas of the cerebellopontine angle

BACKGROUND

Cerebellopontine angle (CPA) lipomas are rare, benign, slow-growing masses. Resections are considered in symptomatic patients who are refractory to targeted medical therapies, but at those stages the lipomas have often reached considerable sizes and encompass critical neurovascular structures. The objective of this study is to develop and to evaluate the utility of a scoring system for CPA lipomas. The hypothesis is that CPA lipomas with lower scores are probably best managed with early surgery.

METHODS

The PubMed database was searched using relevant terms. Data on patient and lipoma characteristics were extracted and used to design a scoring system. CPA lipomas were stratified by scores with corresponding managements and outcomes analyzed.

RESULTS

One hundred and seventeen patients with CPA lipomas were identified and 40 CPA lipomas were scored. The remaining CPA lipomas were deficient in data and not scored. No lipomas were scored as 1. Score 2 lipomas (n = 12; 30%) most often underwent serial surveillances (n = 5; 41.6%), with the majority of symptoms remaining unimproved (n = 2; 40%). Patients with score 2 CPA lipomas treated with medical therapies (n = 3; 25%) often experienced symptom resolution (n = 2; 66.6%) (p = 0.0499). Patients with score 2 CPA lipomas undergoing surgical resections (n = 3; 25%) all experienced symptom resolution (n = 3; 100%) (p = 0.0499). Score 3 was most common (n = 16; 40%) and these lipomas were often surgically resected (n = 10; 62.5%). The majority of patients with score 3 CPA lipomas having undergone surgical resections (n = 10; 62.5%) experienced symptom improvement (n = 1; 10%) or resolution (n = 4; 40%).

CONCLUSIONS

Score 2 CPA lipomas are smaller and would be deemed non-surgical in general practice. However, our data suggest that these lipomas may benefit from either medical therapies or early surgical resections. The advantages of early surgery are maximal resection, decreased surgical morbidity, and improved symptom relief.

A symptomatic Sylvian fissure lipoma in a post-traumatic patient

Lipomatous extra-axial lesions in the Sylvian fissure are a rare entity. Their identification, however, is usually simple if a systematic radiological approach is adopted. The best line of management for these lesions is still a matter of controversy and fraught with complications. We present a case of a Sylvian fissure lipoma referred to our neurosurgery services with symptomatic seizures and in a post-traumatic patient. The radiological differentiating features of intracranial lipomas and intracranial dermoids have been discussed. The unusual location of the lesion, in combination with the history of seizures and the nature of presentation (trauma being a red-herring) make this case an interesting find. The lesion was managed conservatively with good outcomes at follow up, on anti-epileptic medications.

A rare case of intraosseous lipoma involving the sphenoclival region

We describe the case of a 23-year-old man whose CT scan revealed a hypodense lesion reshaping the superior and middle third of the clivus and partially invading the sphenoidal sinus. MRI showed an irregular-shaped lesion occupying the body of the sphenoid bone, involving the superior and middle third of the clivus and sprouting into the sphenoid sinus. The lesion was hyperintense on T1- and T2-weighted sequences with a thin peripheral rim of hypointensity, without enhancement after i.v. gadolinium injection. The pathology report confirmed an intraosseus lipoma. Intraosseous lipomas involving the spheno-clival region are extremely rare. CT and MRI scan interpretation can be troublesome but this rare pathology has to be considered in the differential diagnosis.

Interpeduncular fossa lipoma: a novel cause of oculomotor nerve palsy in childhood

Oculomotor nerve palsy is a rare finding in children and, when reported, is most frequently either congenital or acquired from postnatal trauma, infection, aneurysm, or migraine. Intracranial lipomas also represent an uncommon finding in children, and although their development is not completely understood, they are now thought to be congenital in nature. Here, we describe the case of a 23-month-old boy presenting to the emergency department with left-sided, complete, pupil-involving oculomotor nerve palsy. On magnetic resonance imaging, he was found to have an intracranial lipoma of the left interpeduncular fossa. The patient had gradual and spontaneous improvement of symptoms, with complete resolution reported at the 4-month follow-up visit. However, a second magnetic resonance image at 6 months revealed that the lipoma did not change in size. To our knowledge, intracranial lipomas have been previously reported as a possible cause of partial oculomotor nerve palsy in only one adult and have never been reported in a child. In addition, we did not find any reports of intracranial lipomas as a cause of complete, pupil-involving oculomotor palsy, although they are known to cause other cranial nerve pathology. We conclude that intracranial lipomas, although rare, should be considered in the differential diagnosis for oculomotor nerve palsy in children. Further investigation is needed to determine the true incidence of this association.

Craniofacial features resembling frontonasal dysplasia with a tubulonodular interhemispheric lipoma in the adult 3H1 tuft mouse

Intracranial lipomas are rare, but 45% of them occur along the midline cisterns between the hemispheres and are often associated with corpus callosum hypoplasia and craniofacial defects. They are difficult to detect as they are generally asymptomatic and visible by MRI or by postmortem examination. The exact cause of these interhemispheric lipomas is not known, but they arise from a developmental defect resulting in the maldifferentiation of mesenchymal cells into mesodermal derivatives that are not normally present. We have identified a new mouse mutant called tuft, exhibiting a forebrain, intracranial lipoma with midline craniofacial defects resembling frontonasal dysplasia (FND) that arose spontaneously in our wild-type 3H1 colony. The tuft trait seems to be transmitted in recessive fashion, but approximately 80% less frequent than the expected Mendelian 25%, due to either incomplete penetrance or prenatal lethality. MRI and histologic analysis revealed that the intracranial lipoma occurred between the hemispheres and often protruded through the sagittal suture. We also observed a lesion at the lamina terminalis (LT) that may indicate improper closure of the anterior neuropore. We have mapped the tuft trait to within an 18 cM region on mouse chromosome 10 by microsatellite linkage analysis and identified several candidate genes involved with craniofacial development and cellular differentiation of adipose tissue. Tuft is the only known mouse model for midline craniofacial defects with an intracranial lipoma. Identifying the gene(s) and mutation(s) causing this early developmental defect will help us understand the pathogenesis of FND and related craniofacial disorders.

Sphenoclival intraosseus lipoma: case report and literature review

OBJECTIVE

To present the case of a rare tumor in the sphenoidoclival area and discuss potential pitfalls in diagnosis and management.

DESIGN

Case report with literature review.

SETTING

Tertiary referral center.

CASE SUMMARY

Our patient presented with headache, vertigo, vision problems, and feeling of pressure in the central segment of the face. MR and CT showed a lesion in the body of the sphenoid, with signs of bone destruction and irregular borders. Differential diagnosis included intraosseous meningioma, chordoma, and inflammatory process.

RESULTS

Endoscopic/microscopic transnasal approach was performed to reach clival bone and to biopsy the tumor. Histopathological examination showed intraosseous lipoma.

CONCLUSION

Intraosseous lipoma is a rare tumor, or more accurately a hamartoma, and is usually found in the calcaneus or in the proximal femur. It is even rarer in the skull base. Usually it does not present any symptoms and is an incidental finding during imaging for other symptoms. As a rule it runs an indolent course and does not require any treatment. Since no definitive diagnosis can be made only on the basis of imaging (CT and MRI), it requires an open biopsy that if possible should be made in accordance with the principles of minimally invasive surgery.

Cerebellopontine angle lipoma: a rare differential diagnosis

Intracranial lipomas in an infratentorial and extra-axial location are extremely rare. The presented case of an extensive lipoma of the cerebellopontine angle (CPA) represents 0.05% of all CPA tumors operated on in our department from 1978 to 1996. The lipoma constitutes an important differential diagnosis because the clinical management differs significantly from other CPA lesions. The clinical presentation and management of the presented case are analyzed in comparison to all previously described cases of CPA lipomas. The etiology and the radiological features of CPA lipomas are reviewed and discussed. CPA lipomas are maldevelopmental lesions that may cause slowly progressive symptoms. Neuroradiology enables a reliable preoperative diagnosis. Attempts of complete lipoma resection usually result in severe neurological deficits. Therefore, we recommend a conservative approach in managing these patients. Limited surgery is indicated if the patient has an associated vascular compression syndrome or suffers from disabling vertigo.

Interhemispheric lipoma: Interval development of an associated cyst

We report a case of an 11-year-old patient who underwent CT imaging for complications of sinusitis, and showed incidental development of an interhemispheric cyst in association with an intracranial lipoma over a 10-year interval. Cysts and lipomas are well described in association with dysgenesis of the corpus callosum. We present an uncommon association, of a new cyst in association with an intracranial lipoma, in a patient with a normal corpus callosum.

Rare Bilateral Lipoma of the Internal Auditory Canals

About 10% of all intracranial tumors are localized in the cerebellopontine angle and in the internal auditory canal. Less than 2% of these are lipomas. Furthermore, it can be expected that lipomas in this position with a bilateral localization are exceedingly rare. We describe a 70-year-old-woman with lipomas in both internal auditory canals presented in the literature for the first time and include a detailed literature research.

Interhemispheric osteolipoma with agenesis of the corpus callosum

Osteolipoma is an ossified lipoma with distinct components of fat and bone. We present a case of interhemispheric osteolipoma associated with total agenesis of the corpus callosum. A 20-year-old man complained of severe headache, nausea and vomiting. Brain computed tomography showed a low-density mass in an interhemispheric fissure, with high T1 and T2 magnetic resonance signals compatible with fat. The mass measured 4.9 x 2.9 cm in size and showed peripheral calcifications. There was another small piece of same signal mass within the lateral ventricular choroid plexus. The interhemispheric lesion was removed by an interhemispheric approach. Osteolipoma is rare in interhemispheric region, however, it should be a differential diagnosis of lesions with fat intensity mass and calcifications.

Microsurgical removal of sylvian fissure lipoma with pterion keyhole approach-case report and review of the literature

BACKGROUND

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.

CASE DESCRIPTION

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.

CONCLUSIONS

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.

Problem in diagnostic radiology

The case of a 58-year-old woman is described. She presented with what initially seemed to be a transient ischaemic attack. Clinical imaging, however,revealed an intracranial lipoma of the cisterna magna associated with a defect of the occipital bone and spina bifida occulta of the atlas.

Intracranial lipomas and epilepsy

INTRODUCTION

Intracranial lipomas are rare, mostly congenital lesions. Sporadic case reports suggest an association with focal epilepsy.

METHODS

All admissions to our epilepsy monitoring unit who had had brain MRI were reviewed for intracranial lipomas during 6 consecutive years.

RESULTS

Five patients with intracranial lipomas were identified (0.14%). Lipomas were located in the midline (3 cases), in the tectal region, and over the parietal cortex. Another intracranial pathology was identified in two patients causing the epilepsy in these cases (head trauma and hemimegaencephaly). In two other cases the Video EEG monitoring findings were not congruent with the location of the lipoma, but no other explanation for their epilepsy was found. In one patient a large midline lipoma extending into the right lateral ventricle was thought to be the cause of the patient's right hemispheric seizures. No other clinical symptoms or complications of the lipomas were noted.

DISCUSSION

Intracranial lipomas are rare, incidental, often asymptomatic findings and usually located near the midline. In only one of our five patients was the lipoma interpreted as the definite cause of the epilepsy.

Coexisting intracranial meningeal melanocytoma, dermoid tumor, and Dandy–Walker cyst in a patient with neurocutaneous melanosis

✓ Neurocutaneous melanosis (NCM) associated with Dandy–Walker malformation is a very rare congenital neurodysplasia with the same origin. Primary intracranial melanocytic and dermoid tumors are also benign congenital lesions that usually arise from the leptomeninges and are formed by the inclusion of cutaneous ectoderm at the time of neural tube closure. The authors describe a patient with coexisting intracranial meningeal melanocytoma, NCM with Dandy–Walker malformation, and intraventricular dermoid tumor.

Quadrigeminal cistern lipoma

Intracranial lipomas are rare benign congenital neoplasms accounting for 0.1 to 0.5% of all primary brain tumours. Approximately 50% are associated with other cerebral developmental disorders. These slow growing benign lesions are usually asymptomatic and rarely require surgery. We report the case of a 37 year old woman presented with signs of raised intracranial pressure. Computerized tomography and magnetic resonance imaging demonstrated a quadrigeminal cistern lipoma compressing the aqueduct of Sylvius. The patient underwent surgery and a distinct plane of cleavage between the lipoma and the adjacent neural structures was found, allowing total removal of the lesion. Postoperatively, the patient was relieved of her original symptoms but developed akinetic mutism which lasted for two weeks. Intracranial lipomas rarely become symptomatic and surgery is seldom required. If the lesion progresses and causes symptoms of raised intracranial pressure or compression of neural structures, surgical intervention is indicated. Total removal should not be attempted unless a plain of cleavage between the lesion and adjacent neural structures is present. Surgical manipulation should be minimised to avoid complications.

Cerebral lipoma and the underlying cortex of the temporal lobe: pathological features associated with the malformation

Intracranial lipomas are believed to be congenital malformations rather than true neoplasms, resulting from the abnormal differentiation of the meninx primitiva, the undifferentiated mesenchyme. We report here the surgical pathological features of a lipoma that was located on the cerebral surface of an abnormally formed fissure, and the underlying cortex of the middle temporal gyrus of a 20-year-old woman. The mass was composed of typical adipose tissue in which a large number of blood vessels were present. Thick connective tissue associated with the arachnoid membrane covered the cortical surface. The cortex exhibited a polymicrogyric configuration in which the cortical ribbon was abnormally undulated and excessively folded. Reelin-immunolabeled Cajal-Retzius-cell-like cells were observed frequently in the fused molecular layer. The cortical lamination underlying the molecular layer was poorly defined. Along the border between the connective tissue and cortical surface, there was a narrow zone in which the mesenchymal and neuronal tissues were intermingled, and where immunohistochemical and ultrastructural investigations disclosed disruption of the basal lamina, prominent astrocytosis, and abundant axonal and synaptic profiles. These findings suggest that focal disturbances in cerebral cortical development occur in association with the development of lipomas.

Intraosseous lipoma of the body of the sphenoid bone

A case of intraosseous lipoma arising from the body of the sphenoid bone with intrasellar and suprasellar components is reported. This is the first report of this uncommon tumour occurring in an atypical intracranial site, producing the locally invasive and pressure effects of visual failure and hypopituitarism. The diagnosis was based on computed tomographic (CT) and magnetic resonance (MR) imaging with histological confirmation following frontal craniotomy.

Posterior pericallosal lipoma extending through the interhemispheric fissure into the scalp via the anterior fontanelle

We report an unusual pericallosal lipoma presenting as scalp mass at birth. The patient had no obvious neurological deficit, but CT and MRI revealed a striking lipoma extending extracranially into the scalp from the interhemispheric fissure via the anterior fontanelle. The corpus callosum was distorted but not dysplastic.

Lipomas of the pineal region

BACKGROUND

Intracranial lipomas are rare lesions, representing 0.02% of operated intracranial lesions. Lipomas of the pineal region are even rarer and are reported occasionally in the literature. This is possibly because of the fact that they may give rise to clinical symptoms rather infrequently. When they become symptomatic, some form of management must be contemplated.

METHODS

Four cases of lipomas of the pineal region observed in our institute during a 5-year period were investigated, and clinical-diagnostic features were studied. Two of the cases were symptomatic and were submitted to direct surgical treatment.

RESULTS

Computed tomography (CT) scanning was performed in 3 cases and magnetic resonance imaging (MRI) in all 4. MRI angiography was performed in the last case. The appearance of the lipoma was quite pathognomonic in the neuroimaging diagnostic test. The infiltrative character of the lesion was better defined by MRI. MRI angiography gave evidence of the upward displacement of the deep veins. Direct surgical approach was performed via a right occipital transtentorial approach in one case and supracerebellar route in another. Neither approach appeared to be superior to the other one. Total removal of the lesion seemed to be impossible because of the infiltrative character of the lesion. Postoperative results were satisfactory even with incomplete removal of the lesion.

CONCLUSION

Lipomas of the pineal region are rare. Modern neuroimaging permits a straightforward diagnosis of the nature of intracranial lipomas in general and of these lipomas in particular. Some form of management must be contemplated when these lesions become symptomatic. Direct surgical approach, either via an occipital transtentorial or an infratentorial supracerebellar approach, is feasible. Tumor removal must be dealt with cautiously because total removal is impossible without unacceptable postoperative deficits, and generous partial removal warrants long-term symptomatic improvement.

Cerebellopontine Angle Lipomas: Report of Four Cases and Review of the Literature

OBJECTIVE:

To define the management of internal acoustic meatus and cerebellopontine angle (CPA) lipomas according to their clinical, histological, and surgical characteristics.

METHODS:

We report four new cases of CPA lipomas diagnosed in the Department of Otorhinolaryngology–Head and Neck Surgery of Hôpital Pitié-Salpêtrière and review 94 cases reported previously in the literature.

RESULTS:

Lipomas represented 0.14% of CPA and internal acoustic meatus tumors. Localization was on the left side in 59.9%, on the right side in 37%, and bilateral in 3.1% of the patients. The diagnosis was confirmed radiologically in 33 of 98 patients, surgically in 60 patients, and by autopsy in 5 patients. The most frequent associated symptoms were of cochleovestibular origin, such as hearing loss (62.2%), dizziness (43.3%), and unilateral tinnitus (42.2%). Other associated symptoms involved the facial nerve (9%) or the trigeminal nerve (14.4%). Complete resection was performed in only 32.8% of the patients with frequent cranial nerve involvement. Frequent cranial nerve involvement was seen in 95.4% of all patients. After surgery, patient symptomatology was unchanged in 9.2% of the patients, and 50% were improved; however, new postoperative deficits occurred in two-thirds of the patients. Overall, 72.2% of the patients experienced new postoperative deficits such as hearing loss (64.8%). Preservation of hearing was possible in only 26% of the patients. Only 18% of patients were improved after surgery without any new postoperative deficits.

CONCLUSION:

Preoperative diagnosis of internal acoustic meatus/CPA lipomas is based on magnetic resonance imaging. The aim of surgery in these cases is not tumor removal but cranial nerve decompression or vestibular transection, and surgery is performed only in patients with disabling and uncontrolled symptoms.

Fetal pericallosal lipoma: US and MR findings

We report a case of fetal pericallosal lipoma occurring at the anterior interhemispheric fissure and associated with agenesis of the corpus callosum. During targeted prenatal ultrasonography at 26 weeks' gestation, the lesion was seen as a highly echogenic mass. MR imaging performed at 35 weeks' gestation and during the postnatal period revealed a pericallosal fatty mass and agenesis of the corpus callosum.

Intracranial lipoma of the sylvian fissure. Case report and review of the literature

The authors present a rare case of lipoma of the sylvian fissure found in a 34-year-old man who presented with seizures. The patient underwent craniotomy and an attempted resection of the lesion, which was initially believed to be a dermoid tumor. The imaging characteristics of dermoids and lipomas are extremely similar. Given the difference in the natural history and resectability of these lesions, lipomas should be included in the differential diagnosis of lesions with imaging characteristics similar to dermoids. Currently, tumor location, density of the lesion or computerized tomography scans, and signal homogeneity of the lesion on magnetic resonance images can help one to distinguish these radiographically similar, but pathologically different, entities. As this case confirms, resection of a sylvian fissure lipoma is extremely difficult and potentially dangerous; in addition it is unlikely to improve symptoms. A short review of 10 cases reported in the literature and therapeutic options for these lesions are also discussed.

Intracranial lipomas: demonstration by computed tomography and magnetic resonance imaging

We present two cases of a very rare tumor, intracranial lipoma, diagnosed by computed tomography (CT) and magnetic resonance imaging (MRI). In one case, the lipoma was in the superior cerebellar cistern, the other was in the periphery of the corpus callosum. In the case in which MRI was used, identification of the lipoma using a routine MRI examination was difficult. These cases are reported now because the incidental diagnosis of intracranial lipoma is likely to increase due to advanced neuroradiological techniques such as CT and MRI.

[Lipoma of the corpus callosum associated with the hypertrophy of the corpus callosum: case report]

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.

[Lipoma of the cerebellopontine angle: case report]

Lipoma of the cerebellopontine angle is a very rare tumor. We report the case of a 14-years-old female, with left side deafness during three years, associated with headache. CT scan showed an hypodense mass, without enhancement at the cerebellopontine angle. The patient was treated surgically by left retrosigmoid approach. The lesion involved the eighth and seventh cranial nerves and only a partial removal was performed. The postoperative course was uneventful. She had no more headache; the deafness of the left side remained unchanged. Asymptomatic lipoma of the cerebellopontine angle can be treated conservatively, although those with progressive symptoms should be treated surgically, with total or partial remove based on their neurovascular involvement.

Midline developmental anomalies with lipomas in the corpus callosum region

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.

Suprasellar osteolipoma: case report

BACKGROUND

Osteolipomas are distinguished from other intracranial lipomas by their arrangement of central adipose and peripheral osseous tissues and by characteristically arising in the suprasellar/interpeduncular region.

METHODS

We report computed tomography (CT), magnetic resonance imaging (MRI), and pathology findings from this 34-year-old man who underwent surgical removal of this benign lesion.

RESULTS

This case displays the distinctive histopathology that has been reported in 13 of 31 (42%) lipomas in this region. In contrast, ossification of lipomas at other intracranial sites is relatively rare.

CONCLUSIONS

Ossification should be expected in many suprasellar/interpeduncular lipomas, and osteolipoma should be included in the radiologic differential diagnosis of fat-intensity masses with calcification in this region.

Lipoma of the interpeduncular fossa: demonstration by CT and MRI

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.

Multiple intracranial lipoma: a case report

We report on a male epileptic patient, presently 27 years old, who has suffered complex-partial attacks for 19 years. Under treatment with carbamazepine the seizures were completely controlled. In addition, the patient exhibited partial hypopituitarism. CT and MRI revealed the presence of 2 lipomas, one located within the optico-chiasmatic cistern and the other one in the medial temporal lobe. To our knowledge, this combination of the generally rare lesions has not been described yet.

Dorsal mesencephalic lipoma with inferior collicular hypoplasia: a case report and review of literature

Intracranial lipomas are rare lesions the pathogenesis of which is still a matter of debate. We report the case of a patient presenting an asymptomatic lipoma located in the quadrigeminal and supra-cerebellar cisterns. The lipoma was associated with hypoplasia of the right inferior colliculus and of the rostral part of the vermis. Analysis of the relationships between neural tube and meninges prompts us to propose that the primary event of this malformation is a defect of the neural anlage which gives rise to both nervous dysplasia and lack of meningeal induction responsible for lipoma development.

The Neurosurgical Clinic at the Ludwig-Maximilians University in Munich

ThE NEUROSURGICAL CLINIC at the Ludwig-Maximilians University in Munich began as a small unit of the university's surgical clinic. Eduard Weber, who in 1952 became the first surgeon fully trained in the specialty of neurosurgery to join the surgical clinic's faculty, worked, until his death in 1962, to advance the new specialty. Neurosurgery became an independent department of the university in 1965, and the neurosurgical clinic moved to a new location at Beethovenplatz. Further expansion led the neurosurgical clinic to move again, in 1975, to the newly constructed Klinikum Grosshadern at the periphery of Munich. Frank Marguth, chairman of the department of neurosurgery from 1964 to 1991, had superb skill as an organizer and greatly enhanced the reputation of the department of neurosurgery. Today, the faculty of the department consists of 10 full-time staff members, 10 joint appointment staff members, and 16 residents and fellows. Annually, 2200 to 2300 procedures are performed in the neurosurgical clinic. The current philosophy in the department places heavy emphasis on subspecialization and academic training. Political and economic changes in Germany during recent years have affected the nation's public health system and pose major challenges to the department of neurosurgery.

Dorsal brain stem lipomas: case report

Intracranial lipomas are uncommon and rarely symptomatic lesions accounting for 0.06 to 0.46% of intracranial lesions. The management of symptomatic dorsal brain stem lipomas was once limited to cerebrospinal fluid diversion, but with recent advances in microsurgery, they now may be directly treated. We report three patients with dorsal brain stem lipomas, two of which involved the quadrigeminal cistern and one of which was in the cisterna magna region. Antenatal documentation by ultrasound examination in one patient represents the first reported in utero diagnosis of quadrigeminal cistern lipoma. Computed tomographic and magnetic resonance imaging scans were diagnostic. The surgical experience in two symptomatic patients is discussed. Microsurgical decompression was performed in each without neurological deficit, and clinical symptoms postoperatively subsided. No patient required a permanent cerebrospinal fluid shunt. The management of symptomatic dorsal brain stem lipomas is discussed, and an algorithm is proposed.

Nasal lipomas presenting as part of a syndromic diagnosis

An important part of the initial assessment of children presenting with congenital nasal masses is to exclude an intracranial extension using either magnetic resonance imaging (MRI) or computed tomography (CT) imaging. We present three patients with such lesions in which unusual radiological findings were noted as part of the investigations.

Lipomatous meningioma: characteristic computed tomographic appearance

A case of lipomatous meningioma is reported. This is a rare variant of meningioma in which metaplasia of meningoepithelial cells occurs and mature adipocytes are present within the tumour. The heterogeneous attenuation and heterogeneous enhancement visualized on computed tomography (CT) can mimic necrotic malignant tumours. However, the demonstration of fat attenuation within the tumour explains the heterogeneity and suggests a benign process. The differential diagnosis of an extra-axial fat-containing tumour should include lipomatous meningioma.

Lipomas of the frontal lobe

An extremely rare case of lipomas on the cerebral surface in a 65-year-old female is reported. The tumors were located both in an unusual fissure of the right frontal convexity and under the right frontal lobe associated with and surrounded by areas of focal cortical dysplasia. Angiograms revealed dilated branches of the right anterior cerebral artery associated with angiomatous tumor blushes. The etiology of the combination of the lipomas and the anomalies, and the angiographic features, are briefly discussed.

Agenesis and lipoma of corpus callosum. Case report

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.

O, Matushita H, Plese JPP. Lipoma do corpo caloso com extensão extracraniana através de falha óssea frontal

Os lipomas intracranianos geralmente se localizam no corpo caloso e raramente apresentam expansão para a região subgaleal. Revisão da literatura mostrou que apenas oito casos foram descritos em que o lipoma do corpo caloso se estendia para localização extracraniana através de falha óssea frontal. As manifestações clínicas mais comuns nesses pacientes eram crises convulsivas e retardo mental. A literatura mostra que a ressecção do lipoma de corpo caloso geralmente leva a resultados catastróficos, devendo ser restrita a porção extracraniana do tumor. O caso relatado é de uma criança portadora desta entidade, sem manifestação clínico-neurológica e que foi submetida a ressecção cirúrgica da porção subcutânea do lipoma com finalidade cosmética.