NMR imaging of congenital intracranial germinal layer neoplasms

Correlation of radiological features of white epidermoid cysts with histopathological findings

Epidermoid cysts are benign congenital extra-axial lesions commonly found in the posterior fossa. These lesions have a characteristic imaging appearance on computed tomography (CT) scan and magnetic resonance imaging (MRI), but occasionally they may exhibit atypical radiological features, showing unusual hyperintensity on T1-weighted images (T1WI). Currently, such atypical appearance is referred to as white epidermoid. We present the imaging features of 5 cases of white epidermoid cyst and discuss the possible underlying etiology of this unusual radiological appearance. We retrospectively searched our electronic radiology database from January 2005 to December 2015 for all intracranial epidermoid cysts, which were confirmed either by typical MRI appearance or histopathological examination. All white epidermoid cases were evaluated with non-enhanced CT scan and multisequential MRI. Histopathological correlation was carried out in four white epidermoid cases. A total of 61 patients with epidermoid cyst were found, of those 5 (8%) were considered white epidermoids. These consisted of 3 females and 2 males, ranging in age between 31–63 years (average age was 51.8 years). Three patients had lesions located in the posterior fossa. The 2 other patients had lesions in the suprasellar region, with extension to the right middle cranial fossa in one. All 5 lesions were hyperdense on CT scan and hyperintense on T1WI. One patient demonstrated evidence of transformation of a classic epidermoid to a white epidermoid after partial resection. Histopathologically, cholesterol clefts were seen in 3 epidermoid cysts, each which also showed microcalcifications, proteinaceous material or melanin. Hemorrhage was demonstrated in one additional lesion. White epidermoid cyst is an unusual intracranial lesion that should be considered when encountered with an extra-axial T1 hyperintense lesion. The cause of this hyperintensity is not clearly understood, but the presence of cholesterol, microcalcifications, proteinaceous content and rarely hemorrhage or melanin may be contributing factors.

Infratentorial abscess secondary to dermal sinus associated with dermoid cyst in children: Review of the literature and report of a rare case

Background:

Dermal sinus is usually located at either end of neural tube but most commonly lumbosacral. When occipital, it extends caudally and is mostly localized in the midline position or in the cavity of the fourth ventricle. It could communicate with the skin through a fistula with potential risk of deeper abscesses. Posterior fossa abscess secondary to dermal sinus associated with intracranial dermal cyst is an uncommon pathology.

Case Description:

A 24-month-old girl was admitted to our institution with a cutaneous fistula in the midline of the occipital region. Brain imaging showed an infratentorial intradiploic cyst with peripheral enhancement to contrast medium. The mass showed hyperintensity on T1-weighted sequences, with the lower signal on T2-weighted images. A suboccipital craniotomy was performed with evacuation of the abscess and excision of the capsule. Contextually a 3 cm whitish and encapsulated cystic mass with hair component was extracted. Histology confirmed the diagnosis of abscess associated with dermal cyst and dermal sinus. The patient condition improved and 15 days after excision, was discharged. The postoperative MRI showed total removal of the lesion. A 36-month follow-up highlighted no evidence of recurrence.

Conclusion:

Posterior fossa dermoid cyst should be considered in all children with a cutaneous fistula. Early neurosurgical treatment of these benign tumors should be performed to prevent the development of severe intracranial infection. Best results are associated with early diagnosis and complete removal of the abscess. The present work further reviews the few similar cases that have been reported in the literature confirming the need for future research.

Interdural cavernous sinus dermoid cyst in a child: case report

Interdural dermoid cysts (DCs) of the cavernous sinus (CS), located between the outer (dural) and inner layer (membranous) of the CS lateral wall, are rare lesions in children. The authors report on a 5-year-old boy with third cranial nerve palsy and exophthalmos who underwent gross-total removal of an interdural DC of the right CS via a frontotemporal approach. The patient had a good outcome and no recurrence at the 12-month follow-up. To the best of the authors' knowledge this is the second pediatric case of interdural DC described in the literature.

Role of MRI in Diagnosis of Ruptured Intracranial Dermoid Cyst

Introduction:

Intracranial dermoid cystic tumors account for <1% of all intracranial masses.

Case report:

A 52-year-old male, having headaches, nausea and is presented with a history of 2 episodes of new onset seizures. On presentation, the patient had a normal physical exam, including a complete neurological and cranial nerve exam.

Methods:

Precontrast MRI; TSE/T2Wsequence in axial/coronal planes; 3D – HI-resolution T1W sagittal; FLAIR/T2W axial; FLAIR/T2W, Flash/T2W oblique coronal plane, GRE/T2W axial. Post-contrast TSE/T1W sequence in axial, coronal and sagittal planes. Diffusion weighted and ADC mapping, postcontrast: TSE/T1W sequence in axial, coronal and sagittal planes.

Results:

Subsequent MRI of the brain revealed an oval and lobulated 47x34x30mm (TRxAPxCC) non-enhancing T1-hyperintense mass in right cavernous sinus, with compression of surrounding mesial temporal lobe and right anterolateral aspect of mesencephalon. Findings are consistent with ruptured dermoid cyst, given the evacuated sebum content at its lower half. Sebum particles in millimetric sizes are seen within right Sylvian fissure, anterior horns of lateral ventricles and to a lesser extent within left Sylvian fissure, right parietal sulci, cerebral aqueduct, and basal cisterns. No restricted diffusion is seen, eliminating the possibility of epidermoid. A shunt catheter is evident traversing between right lateral ventricle and right parietal bone; besides, slit-like right lateral ventricle is noted (likely secondary to over-draining shunt catheter).

Conclusion:

Intracranial dermoid cysts are benign rare slow-growing tumors that upon rupture, however, widespread presence of T1 hyperintense droplets and leptomeningeal enhancement can be noted–making MRI the best imaging modality for diagnosis of this rare entity.

Epidermoid tumors of the temporal lobe as epileptogenic foci

Intracerebral epidermoid tumors of the temporal lobe are exceedingly rare. The vast majority of these slow-growing tumors remain clinically silent while only a select few are associated with overt symptomatology. We report two patients with epidermoid tumors whose unique location in the temporal lobe resulted in secondarily generalized seizures. Our first patient, a 19-year-old female, presented with a secondarily generalized tonic-clonic seizure and MRI revealed a superior temporal lobe lesion that was subsequently treated with an awake craniotomy and gross total resection. Our second patient was a 71-year-old male with a recent seizure history and known left temporal lobe lesion. The patient underwent craniotomy for gross total resection of the mass. In these two patients, we found that MRI proved diagnostic and surgical resection was curative. Our clinical experience and review of the literature indicate that gross total resection of these lesions confers control of localization-related epilepsy.

Ruptured intracranial dermoid cyst manifesting as new onset seizure: a case report

Intracranial dermoid cysts are rare tumors derived from ectopic epithelial cells. They are slow-growing benign entities, but can cause significant morbidity through compression of neurovascular structures and, rarely, rupture into the subarachnoid space. We present a rare case of a spontaneously ruptured intracranial dermoid cyst presenting as new onset seizures due to chemical meningitis caused by dissemination of fat droplets.

A supratentorial, hemorrhagic, intraparenchymal epidermoid cyst

Epidermoid cysts are slow growing benign tumors that represent < 1-2% of all intracranial tumors and rarely present as supratentorial, intraparenchymal masses. We present the first report of a supratentorial, hemorrhagic, intraparenchymal epidermoid cyst with its presentation, our operative approach, post-operative course, radiographic features, and a literature review.

Epidermoids of the cerebellopontine angle: a 20-year experience

BACKGROUND

There is considerable debate within the current literature whether total or subtotal removal of CPA epidermoids yields better long-term outcomes. The aim of this study was to review our experience with cerebellopontine-angle epidermoid tumors, as well as the current literature, focusing on the correlation between long-term outcome and the extent of surgical removal.

METHODS

We performed a retrospective review of 24 patients with epidermoid tumors of the CPA surgically treated at our institution between 1985 and 2005.

RESULTS

The mean duration from onset of symptoms to surgery was 3.1 years. Cranial nerve dysfunction was noted in 83% of patients preoperatively. Total removal was achieved in 13 patients, near total removal in 6 patients, and subtotal removal in 5 patients. Patients who underwent total removal had a median MRS score of 0, whereas those who underwent near/subtotal removal had a median MRS score of 1. The rate of recurrence was 23% in tumors considered totally removed and 27% in those near/subtotally removed. Of the 6 patients with recurrences, 5 underwent a second operation. The mean duration of follow-up was 4.2 years.

CONCLUSIONS

Total removal of CPA epidermoids does not result in significantly increased morbidity and mortality and should be the goal of surgical treatment. However, near/subtotal resection of lesions that extend far beyond the CPA or are densely adherent to neurovascular structures is justified, as there is no significant difference in the rate of recurrence.

Dermoid lesion of the cavernous sinus: case report and review of the literature

Intracranial dermoids are rare congenital tumors. Supratentorial dermoid cysts were more frequently reported in the last decade, and they are known to have a predilection for the cavernous sinus. Interdurally localized dermoids presenting with ophthalmoplegia is uncommon. Previously, the association of dermoid lesions with the cavernous sinus and the complexity of the operative procedure were emphasized only by a few authors. We report a case of a dermoid cyst that was embedded fully in the cavernous sinus and review the related cavernous dermoid lesions in the literature. Fronto-orbitozygomatic craniotomy was performed, and despite adherence of the tough capsule to the cranial nerves, the lesion was grossly removed in total. The patient was doing well 1 year after the operation, and there was no recurrence of signs and symptoms. Interdural growth of cavernous dermoid tumors must be considered, and careful evaluation of preoperative computed tomography and magnetic resonance images aids in making the decision concerning the operative approach. Upon review of the literature, we detected only eight similar cases concerning cavernous dermoid cysts. Although total excision of these cavernous lesions has been reported previously, we believe that total excision can sometimes be hazardous and not feasible.

Pathogenesis of intraparenchymal epidermoid cyst in the brain: a case report and review of the literature

BACKGROUND

Intracranial epidermoid cysts are relatively common; however, epidermoid cysts in the brain parenchyma are rare. In addition, the etiology of intraparenchymal epidermoid cysts is not clear.

CASE DESCRIPTION

A 61-year-old woman presented with convulsive seizures. CT and MRI revealed a mass lesion in the right parietal lobe. With low-grade glioma as a preoperative diagnosis, the tumor was totally excised, but the subsequent pathologic diagnosis was epidermoid cyst.

CONCLUSION

Exact preoperative diagnosis of this disease would be helpful in preventing chemical meningitis. The etiology is likely related to the time and locus of sequestration of ectodermal tissue during fetal development. Clarifying the pathogenesis will lead to effective preventive measures.

Expanding experience with spontaneous dermoid rupture in the MRI era: diagnosis and follow-up

With widespread use of CT and MR imaging, experience with spontaneous dermoid rupture has significantly increased. What was previously believed to be a generally severe or even fatal accident, being the diagnosis made either at surgery or autopsy, or in patients with such consequent conditions as chemical meningitis or obstructive hydrocephalus, now appears to be more frequent than previously thought, and there is some evidence that it may also cause only a slight symptomatology or even be quite asymptomatic. We reviewed the clinical and imaging data of our series of five patients with spontaneously ruptured dermoids, spinal in one case, and intracranial supratentorial in four. These had their diagnosis following mild symptoms (number two cases) or incidentally (number two cases); the spinal tumor caused acute bladder dysfunction, possibly while undergoing rupture, and was associated with indolent intracranial fat spread. Three of the patients also had MR demonstration of asymptomatic persistence of fat spread in the subarachnoid spaces, respectively, 3, 4, and 5 years after rupture. One of the five cases, concerning a parasellar dermoid followed up over 6 years, provides the first demonstration of MR signal intensity change of the tumor prior to rupture.

Ruptured intracranial dermoid cysts

BACKGROUND

Intracranial dermoid cysts are rare congenital neoplasms that are believed to arise from ectopic cell rests incorporated in the closing neural tube. The rupture of an intracranial dermoid cyst is a relatively rare event that typically occurs spontaneously. In the past it was believed that rupture is always fatal, a hypothesis that is not supported by more recently reported cases. The symptoms associated with rupture vary from no symptoms to sudden death.

METHODS

The present paper analyzes published cases of ruptured intracranial dermoid cysts in terms of their age profile and their clinical presentation and describes an additional case.

RESULTS

Analysis of published cases revealed headache (14 out of 44 patients; 31.8%) and seizures (13 out of 44 patients; 29.5%), to be the most common signs of rupture followed by, often temporary, sensory or motor hemisyndrome (7 out of 44 patients; 15.9%), and chemical meningitis (3 out of 44 patients; 6.9%).

CONCLUSION

Headache occurred primarily in younger patients (mean age 23.5 +/- 9.3 years), whereas seizures primarily occurred in older patients (mean age 42.8 +/- 11.3 years). The patients with sensory or motor hemisyndrome associated with rupture of an intracranial dermoid cyst showed a more homogeneous age distribution (mean age 38.4 +/- 23.5 years).

Mobile intracranial oily substances from a ruptured teratoma

A patient with a ruptured intracranial teratoma is presented. The distinctive imaging and neuroendoscopic findings of mobile fatty or oily globules in the subarachnoid or ventricular space are described. Fat suppression magnetic resonance imaging (MRI) and MRI performed with the patient prone was helpful in distinguishing tumour tissue from floating oil.

Pineal epidermoid cysts: diagnosis and management

OBJECT

The results of surgical treatment of epidermoid cysts of the pineal region in six cases are presented.

METHODS

Six patients with pineal epidermoid cysts underwent surgery at the Institute of Neurosurgery "N. N. Burdenko," in Moscow, during the period 1976 to 1995. The duration of the patients' preadmission clinical history varied from 6 months to 2 years (average 1.4 years). Headache, diplopia, and vertigo were the most frequently occurring symptoms. Neurological examination demonstrated papilledema, impaired pupillary reaction, ataxia, and long-pathways deficit; Parinaud's syndrome was found in only one case. Computerized tomography and magnetic resonance imaging constituted the primary diagnostic tools. Surgery was performed using either an infratentorial-supracerebellar approach (two cases) or an occipital-transtentorial approach (four cases).

CONCLUSIONS

Surgical results can be excellent if a removal, as extensive as possible, is performed using either the supracerebellar or occipital-transtentorial approach.

Magnetic resonance imaging of a medullary dermoid cyst with secondary hydrocephalus in a dog

Magnetic resonance images were acquired of the brain of a 7-year-old male Golden Retriever with hydrocephalus secondary to a medullary lesion. Images were acquired prior to and 4 weeks following surgical treatment for the hydrocephalus, and the dog was euthanased following the second imaging session. The MR images demonstrated a medullary lesion with patchy but predominantly hyperintense signal with both T1- and T2-weighting, within which small areas of low signal were scattered. There was little edema associated with this lesion and no enhancement with gadolinium. Postmortem examination revealed the medullary mass to be a dermoid cyst. Several small nodular lesions were identified within the central nervous system on the magnetic resonance images whose origin was uncertain on postmortem examination.

Assessment and surgical management of posterior fossa epidermoid tumors: report of 28 cases

OBJECTIVE

The management of a series of 28 patients operated on for posterior fossa epidermoids is reviewed, emphasizing the need for long-term follow-up. We discuss the rationale for a comprehensive classification system that may allow the comparison of results from homogeneous series.

METHODS

We grouped the tumors to differentiate the surgical management according to various tumor sites and the degree of extension. Twenty patients harbored tumors located in the cerebellopontine angle, five patients harbored tumors in the fourth ventricle, and three patients harbored tumors in the posterior fossa basal. In 17 patients, extensions of tumors outside the posterior fossa included the following regions: the suprasellar/ chiasmatic (n = 5), the parasellar/temporobasal (n = 5), and the mesencephalic/pineal (n = 7). Tumor extension was also defined by the number of regions involved. Pre- and postoperative magnetic resonance imaging and computed tomographic findings collected in 17 and 28 patients, respectively, were carefully evaluated.

RESULTS

Clinical features and surgical approaches varied according to location and growth pattern. Fifty-seven percent of the tumors were completely removed. A higher total removal rate was achieved in patients with tumors confined to the primary location. One patient (3%) died in the perioperative period. Approximately half of the patients presented with transient mild focal deficit impairments resulting from the manipulation of the nervous structure over a wide area. There was a higher rate of surgical complications with fourth ventricle and mesencephalic extended cerebellopontine angle tumors. The mean follow-up period was 8.6 years. Thirty percent of the patients with subtotal removal experienced symptomatic recurrences after 8.1 years, whereas all patients with total removal were still asymptomatic. The recurrence-free survival rate was 95% at 13 years for patients with total removal compared with 65% for patients with subtotal removal. Problems of identification of tumor regrowth are discussed.

CONCLUSION

By assessing posterior fossa epidermoids, we determined that location and extension play a major role in the prognosis. Our data suggest that more aggressive surgery is called for at first operation, and that a second operation should be planned when regrowth becomes symptomatic and/or tends to extend outside its original site.

Pineal region tumors and the role of stereotactic biopsy: review of the mortality, morbidity, and diagnostic rates in 370 cases

OBJECTIVE

It is classically considered that the morbidity and mortality rates are greater for stereotactic biopsies of pineal region tumors, compared with tumors in other regions. However, to date, the number of cases studied in the literature has been insufficient to evaluate these parameters and compare them with the morbidity and mortality rates for stereotactic biopsies of tumors located elsewhere.

METHODS

With the aim of evaluating these parameters, we reviewed 370 stereotactic biopsies of pineal region tumors, from 15 French neurosurgical centers. We statistically verified the absence of heterogeneity of the different French centers with regard to diagnostic, mortality, and morbidity rates. In contrast, statistical heterogeneity was clearly seen for the large stereotactic biopsy series (for all tumor locations) in the literature.

RESULTS

The mortality rate was 1.3% (5 patients of 370), and 3 patients suffered severe neurological complications. This study is the first to clearly demonstrate that the mortality, morbidity, and diagnostic rates for stereotactic biopsies are not different in the pineal region.

CONCLUSION

Our conclusion is that stereotactic biopsy must remain a main diagnostic modality for tumors of the pineal region.

Three-dimensional chemical shift-selective MRI of a ruptured intracranial dermoid cyst

We report a man with a ruptured intracranial dermoid cyst, suffering from headache, nausea, vomiting and a generalised seizure. MRI was performed before and 2 weeks after surgical resection. On T1-weighted images the tumour gave high signal, as did fatty material in the frontal and parietal brain sulci. Identification of this hyper-intense material as lipids was possible by chemical-shift-selective 3D gradient-echo imaging, which provided excellent contrast between the subarachnoid lipids and the adjacent normal brain, with a good spatial resolution. Possible complications of subarachnoid and intraventricular lipid particles after dermoid cyst rupture are discussed and the diagnostic value of 3 D chemical-shift-selective additional to conventional T-1-weighted spin-echo images in identification of even small amounts of fat is emphasised.

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.

Spinal dermoid cysts originating intracranial fat drops causing obstructive hydrocephalus: case reports

The authors report two cases of spinal dermoid cysts whose rupture originated the migration of free fat drops into the ventricles and intracranial subarachnoid spaces. In both cases the fat drops caused obstructive hydrocephalus, which represents a quite exceptional complication. Moreover, one of the cases is unique, since the finding of intracranial fat causing hydrocephalus considerably preceded the discovery of the spinal neoplasm. The authors suggest that the finding of intracranial fat in the absence of a local source makes the search for a intraspinal dermoid or epidermoid tumor mandatory.

Familial hypercholesterolemia and intracavernous venous spilling of cholesterol in a child with large suprasellar dermoid cyst. Case report

A unique case of suprasellar dermoid cyst and familial hypercholesterolemia in a child is reported. Such an association, which strengthens the congenital hypothesis of dermoid cysts, could be a manifestation of a complex dyslipidemic inherited syndrome, at least in children. Surgical removal of the dermoid cyst which spilled cholesterol into the cavernous and intercavernous sinuses, allowed reduction of cholesterol levels in the postoperative period.

Craniocerebral epidermoid and dermoid tumours: a review of 32 cases

We reviewed 22 epidermoid and 10 dermoid tumours of the skull and brain from patients operated on consecutively at Henry Ford Hospital between 1975 and 1991. There were 19 intradural (16 epidermoid, 3 dermoid) and 13 extradural (6 epidermoid, 7 dermoid) lesions. The average age at presentation was 35 years for patients with epidermoids and 15 years for those with dermoids. Common clinical presentations for patients with intradural lesions included headache, visual deficits, and seizures, whereas patients with extradural lesions harbored asymptomatic scalp masses. All patients with intradural lesions were investigated with computed tomography (CT) and cerebral angiography, and 8 patients underwent magnetic resonance imaging (MRI). Total resection was possible in 12 (92%) of 13 extradural tumours, all with excellent outcomes. Eight (42%) of the intradural tumours were completely resected. Overall, with the intradural tumours we had good to excellent results in 17 patients (90%), poor results in 1 (5%), and 1 death (5%). Re-operation was needed in 5 intradural recurrences (26%) with deterioration in only one patient's neurologic status postoperatively. From a review of ours and others' data, we conclude that 1) these tumours have an insidious onset despite significant size and mass effect as demonstrated by imaging studies; 2) CT, angiography, and particularly MRI help to define the extent of subarachnoid tumour spread and involvement of neurovascular structures, thus permitting better surgical planning; 3) a significant number of intradural tumours are difficult to excise because of their adherence to neurovascular structures, and thus are related to higher morbidity and mortality; and 4) because of extremely slow growth, complete tumour resection should not be the goal at the risk of injury to neurovascular structures.

Dermoid tumor with persistently low CSF glucose and unusual CT and MRI findings

A patient with dermoid tumor, presenting with persistent hypoglycorrhachia in the absence of cerebrospinal fluid pleocytosis is reported. The presence of ring enhancements without infection, surrounding edema, and mass effect on computed tomography and magnetic resonance imaging are unusual findings for these tumors.

Signal intensity patterns in intraspinal dermoids and epidermoids on MR imaging

Retrospective evaluation of MR images of nine intraspinal dermoid (n = 4) and epidermoid (n = 5) tumours was undertaken. T1-weighted images were available in all the patients while proton density (PD) and T2-weighted images were available in seven patients. Except for one lesion (only T1-weighted images were available in this case), all the lesions were clearly delineated on MR images. Most (5 out of 7) were better appreciated on T1- and PD-weighted images than on T2-weighted images. On T1-weighted images, the epidermoids were either iso- to mildly hypointense to the cord (n = 3), isointense to CSF (n = 1) or markedly hyperintense (n = 1). On the PD images, the epidermoids were either isointense to cord (n = 3) or markedly hyperintense (n = 1). All the lesions were iso- to hyperintense to CSF on T2-weighted images. Of the four dermoids three showed a mixed intensity pattern on all sequences; the dominant component gave short T1 and short T2 values, consistent with fat. The fourth lesion showed homogenous material with a signal intensity intermediate between that of CSF and cord on T1-weighted images. Dermal sinus tracts were present in four of the nine patients; three patients had an intraspinal component. This study shows that although MR imaging is excellent for their detection, it cannot differentiate the two tumour types.

Dermoid of cavernous sinus resulting in isolated oculomotor nerve palsy

Intracranial dermoid cysts and acquired oculomotor nerve palsies are individually rare in childhood. This report describes a 4-year-old boy with acute oculomotor nerve palsy and pupillary sparing secondary to a dermoid within the lateral wall of the cavernous sinus. The clinical signs resolved after complete surgical excision of the tumor with no evidence of recurrence on computed tomography 1 year later. This is the first case report in childhood of a dermoid within the cavernous sinus and of an isolated oculomotor nerve palsy due to a dermoid cyst.

Congenital inclusion cysts over the anterior fontanel in Japanese children: a study of five cases

Congenital inclusion cysts over the anterior fontanel are rare in children in Asia and Europe. However, recent evidence of an increase in cases in both areas has been presented. In the period from 1980 to 1989, four patients with a dermoid cyst and one with an epidermoid cyst have undergone total excision in our department. Including the previously reported Japanese cases, the number of recorded Japanese cases is now 15, the number of Asian cases thus corresponding to the number in Europe. Although these lesions are unlikely to have intracranial extensions, noninvasive neuroimaging methods such as computed tomography and magnetic resonance imaging are recommended for preoperative investigations.

Intraventricular fat from a ruptured sacral dermoid cyst: clinical, radiographic, and pathological correlation. Case report

The authors report a unique case of a dermoid cyst that ruptured into the lumbosacral subarachnoid space following trauma, resulting in dissemination of cyst contents into the ventricles and cerebrospinal subarachnoid spaces. An intraspinous source should be considered when intraventricular fat is identified without a clear intracranial source.

Intracranial tumours in the first year of life. A report on 51 cases

The authors report on 51 infants with intracranial tumours treated in an eleven-year period; these infants represent 13% of the total population of children with intracranial tumours who have been operated on in the same institution during the same period of time. Males (28 cases) were slightly more frequent. Astrocytomas (17 cases), medulloblastomas (12 cases), and ependymal tumours (5 cases) were the commonest histologic types. Signs and symptoms of increased intracranial pressure were by far the most frequent clinical manifestations, followed by seizure disorders. Thirty tumours were localized within the supratentorial, and 21 within the subtentorial compartment. The parasellar region (10 cases) and the lateral cerebral ventricles (8 cases) for the supratentorial tumours, the inferior cerebellar vermis and fourth ventricle (13 cases) for the infratentorial tumours appeared to be the preferred topographic locations. Craniotomies were carried out in 44 infants, with a total or radical removal of the tumour in 19 cases, a subtotal removal in 6 cases, and a partial removal in 17 cases. In 3 cases only a biopsy procedure was performed. Twenty-nine of these patients required an ancillary procedure such as CSF shunting. Three subjects underwent a biopsy procedure and 1 infant the insertion of a CSF shunting device only. Surgery was not performed in 5 cases. Overall, there were two surgical deaths. Two infants died before any surgical treatment could be performed. Radiation therapy was administered to 9 patients when they had reached three years of age. Chemotherapy was given to 21 infants, according to various chemotherapeutic protocols. During the postoperative period 20 deaths (39%) were recorded. Two patients were lost to follow-up. From 1 to 10 years after the operation, 29 patients are still alive, 14 of them (28%) with a normal psychomotor development, 10 (20%) with some neurological or mental deficits, and 5 (10%) with severe psychomotor retardation. There was no apparent correlation in this series between late outcomes and the histological type of the tumour.

Ruptured suprasellar dermoid associated with middle cerebral artery aneurysm: case report

Dermoid tumor associated with cerebral aneurysm is extremely rare. We report here a case of ruptured suprasellar dermoid cyst associated with middle cerebral artery (M1) aneurysm and stenosis of adjacent arterial trunks. The characteristic feature of this association is the tight adhesion of the vascular lesion to the tumor capsule.

Transtentorial epidermoid cysts

Epidermoid cysts may occur simultaneously above and below the tentorium. Eleven patients with involvement of both infra- and supra-tentorial cisterns are presented. In two cases the epidermoid, located mainly in the cerebello-pontine angle, spread into the middle cranial fossa; in three the epidermoid extended from the parasellar cisterns to the posterior cranial fossa; in six patients the epidermoid, enlarging the tentorial notch, occupied extensively both cranial fossae. The surgical approach was influenced both by the experience of the surgeon and by the main extension of the epidermoid. Total removal was feasible in two patients only but only one of the eleven patients had a recurrence of the epidermoid. The long term results appear to be unrelated to the size of the epidermoid and to the choice of approach.

Magnetic resonance of intracranial epidermoids

The magnetic resonance images of seven patients with biopsy-proven epidermoids were evaluated. The epidermoids were hypointense on T1-weighted images. Intermediate density images revealed the tumors to be heterogeneous in signal intensity consisting of areas of hypo- and isointensity. Signal intensity on T2-weighted images was hyperintense and inhomogeneous in all but one case. CT performed in five patients demonstrated the tumors to be well-defined hypodense lesions without contrast enhancement.

Supratentorial dermoid cysts

Supratentorial dermoid cysts are rare lesions. In eight cases presented here, the lack of recurrence after subtotal removal of the capsule and the good long-term prognosis are emphasized. This finding is in agreement with the literature. The frequent relationship of these lesions with the cavernous sinus suggests a vascular genesis in the development of intracranial dermoid cysts.

CT and MRI of ruptured intracranial dermoids

Two patients with ruptured intracranial dermoids, examined with both CT and MRI are reported. Clinical presentation was transient cerebral ischemia in one patient and acute meningeal signs in the other. CT scan showed typical fat density of the tumor and the subarachnoid space. On MRI both the tumor and the subarachnoid fat, were strongly hyperintense on T1-weighted images.

Long-term results of surgical treatment of cerebello-pontine angle epidermoids

The long term surgical results in a series of 17 epidermoids of the cerebello-pontine angle are reported. In 11 cases the capsule was removed subtotally and in 6 totally. The absence of mortality among the patients who underwent subtotal removal and the onset of recurrences, if any, only long after the first operation, justify subtotal removal when tight capsular adhesions are present.

Dermoid cysts of the posterior cranial fossa in children. Report of nine cases and review of the literature

Dermoids of the posterior cranial fossa in children are rare. We report the clinical and pathological data on nine children with these lesions. A mean follow-up of 17.3 years after total removal confirms the excellent prognosis irrespective of whether the presenting symptom is meningitis or intracranial hypertension. A brief review of 39 published cases follows.

Huge pineal teratoma mimicking a dermoid cyst. Case report

A case of huge pineal teratoma mimicking a dermoid cyst is reported. Although both computed tomography and surgical findings were entirely similar to those of a dermoid cyst, close histological examinations using the serial sectioning technique of a small solid portion attached to the pineal region revealed tissue components of both mesodermal and entodermal origins among mostly epidermal and dermal components. The importance of serial sectioning of the surgical specimens of seemingly a dermoid cyst is stressed.

Magnetic resonance imaging of calvarial eosinophilic granuloma

A small calvarial eosinophilic granuloma is demonstrated with T2 weighted magnetic resonance imaging.

Magnetic resonance imaging of the brain and spine

The efficacy of magnetic resonance imaging (MRI) in the diagnosis of diseases of the central nervous system is reviewed. MRI, computed tomography (CT) and certain radionuclide studies are compared in the evaluation of intracranial tumours, cerebral vascular disease, multiple sclerosis and other white matter diseases, dementia, head injury, infection, epilepsy, spinal lesions and in paediatric central nervous system disorders. The measurement of cerebrospinal fluid volumes and dynamics by MRI is discussed. MRI most clearly has advantages where CT is degraded by bone hardening and streak artefacts (spine, skull base, posterior and temporal fossa, sella and parasellar regions) and in diseases in which the X-ray attenuation of the suspected lesion differs little from normal parenchyma (paediatric brain disorders, demyelination and dysmyelination, early oedema associated with infarction, infection or low-grade infiltrating neoplasm, subacute and chronic haemorrhage and lesions in the spinal subarachnoid space and cord). Elsewhere MRI and CT should be seen as complementary rather than competitive methods of imaging. In spite of an absence of information about the contribution of MRI to management decisions and a lack of rigorous, prospective controlled trials, MRI will play an increasing role in the diagnosis of diseases of the central nervous system.

MR imaging of epidermoid cysts

After a short review of literature, MRI assessments of four cases of epidermoid cysts (EC) are reported. EC, (characterized in computed tomography by hypo or iso-density areas non-enhanced by contrast), are characterized in MRI by: 1) an important variability of signal intensity between the different cases, and sometimes between the different parts of the same cyst, 2) the absence of edema in surrounding parenchyma, in spite of important mass effect, 3) well defined limits, permitting certainty of the extra-cerebral nature of this tumor, 4) the presence of calcifications easily perceptible in MRI. It is proposed that the variability of signal intensity of EC is caused by different relaxation time values corresponding to different concentrations of keratin, cholesterol and water content.

Magnetic resonance imaging and management of a pineal region dermoid

We report the case of a 19-year-old man harboring a pineal region dermoid, of which only eight other cases have been reported. A diagnosis was made with magnetic resonance imaging (MRI), which showed a marked high signal intensity on both T-1 and T-2 weighted images that is consistent with the lipid character of the lesion. Residual tumor could be seen on postoperative MR images. MRI is an accurate, noninvasive modality for the diagnosis and follow-up evaluation of these tumors.

Magnetic resonance imaging of the brain in children

Differences between MRI of the brain in children and adults are discussed. These include the need for sedation, greater difficulties in obtaining normal controls and substantial differences in pulse sequences due to changes in T1 and T2 with age. The common features in the major pathological entities are presented and the need to relate them to physiological changes is emphasized.