Tumour-like Lesions

The relevant intracranial cysts and tumour-like lesions according to the World Health Organization will be reviewed but most attention will be paid to non tumoral pathology that may behave like a tumour on imaging. It is important to depict these non-tumoral lesions because of the different therapeutic approach.

Usefulness of FDG-PET to diagnose intravascular lymphoma with encephalopathy and renal involvement

Intravascular lymphoma (IVL) is a rare subtype of extranodal diffuse large B-cell lymphoma. It is characterized by proliferation of neoplastic Lymphoid cells almost exclusively within the lumina of small blood vessels. It can affect virtually every organ system. Due to its rarity and its diverse and heterogeneous clinical presentation, diagnosis is difficult and often made post-mortem. When diagnosed early, it is, however, potentially treatable. We present a young woman with longstanding constitutional symptoms, positive antinuclear antibody, elevated LDH levels and rapidly progressive encephalopathy. FDG-PET scan showed intense uptake in the renal cortex, which prompted us to perform a kidney biopsy which was compatible with IVL. The value of PET in establishing the diagnosis of this rare disease will be discussed.

Identification of a novel PEX14 mutation in Zellweger syndrome

BACKGROUND

Peroxisome biogenesis disorders are a clinically and genetically heterogeneous group of very severe autosomal recessive disorders caused by impaired peroxisome biogenesis. The prototype of this group of disorders is the cerebro-hepato-renal syndrome of Zellweger.

METHODS AND RESULTS

Here we report a patient with Zellweger syndrome, who presented at the age of 3 months with icterus, dystrophy, axial hypotonia, facial dysmorphy, posterior embryotoxon, and hepatomegaly. Abnormal findings of metabolic screening tests included hyperbilirubinaemia, hypoketotic dicarboxylic aciduria, increased C(26:0) and decreased C(22:0) plasma levels, and strongly reduced plasmalogen concentrations. In fibroblasts, both peroxisomal alpha- and beta-oxidation were impaired. Liver histology revealed bile duct paucity, cholestasis, arterial hyperplasia, very small branches of the vena portae, and parenchymatic destruction. Immunocytochemical analysis of cultured fibroblasts demonstrated that the cells contain peroxisomal remnants lacking apparent matrix protein content and PEX14, a central membrane component of the peroxisomal matrix protein import machinery. Transfection of fibroblasts with a plasmid coding for wild-type PEX14 restored peroxisomal matrix protein import, indicating that the primary genetic defect affecting the patient is indeed linked to PEX14. Mutational analysis of this gene revealed a genomic deletion leading to the deletion of exon 3 from the coding DNA (c.85-?_170+?del) and a concomitant change of the reading frame (p.[Ile29_Lys56del;Gly57GlyfsX2]).

CONCLUSIONS

This report represents the second PEX14-deficiency associated with Zellweger syndrome and the first documentation of a PEX14-deficient patient with detailed clinical follow-up and biochemical, morphological, and radiological data.

Lacrimal gland and perioptic nerve lesions due to Langerhans cell histiocytosis (2007: 9b)

We report a patient presenting with bilateral lacrimal gland involvement and perioptic nerve sheath lesions due to Langerhans cell histiocytosis (LCH) invasion. LCH is a rare multisystemic disease characterized by a clonal proliferation of Langerhans cells. All organs may be involved with a clinical spectrum ranging from a solitary bone lesion to a severe life-threatening multisystem disease. Osteolytic orbital bone lesions with extension into the adjacent orbital soft tissues have been described. To our knowledge, lacrimal gland involvement has probably been described only once before. Perioptic nerve lesions are also very rare, having been described only three times before.

A diffusion-weighted template for gestational age-related apparent diffusion coefficient values in the developing fetal brain

OBJECTIVE

To determine the pattern of apparent diffusion coefficient (ADC) values in the normal fetal brain obtained with diffusion-weighted images (DWI) on magnetic resonance imaging (MRI) as a template for normal brain development throughout gestation.

METHODS

This was a prospective study of 46 fetuses without suspicion of brain pathology undergoing a total of 66 ultrasound examinations between 17 and 37 weeks of gestation. At T2-weighted MRI, four left and four right brain regions were delineated on transverse slices of the native DWI using a b-value of 0 s/mm2 (b0 images). We examined native b-value images and calculated ADC(avg), ADC(low) and ADC(high) in the basal ganglia, cerebellar hemisphere, frontal parenchyma and occipital parenchyma. Linear regression analysis was used to assess the relationship between gestational age and b0 values as well as the calculated ADC values.

RESULTS

Delineations were successful in all fetuses for all regions except for the cerebellar hemispheres in four fetuses. There was a negative correlation between gestational age and b0 values in all examined anatomical regions (P<0.002). For ADC(avg), there were no significant changes in the basal ganglia with increasing gestational age, a positive correlation in the frontal (P<0.0001) and occipital (P=0.03) parenchyma and a negative correlation in the cerebellar hemispheres (P=0.01). For ADC(low), there was a negative correlation between gestational age and the cerebellum (P=0.0002) and basal ganglia (P=0.047), but no correlation for the frontal or occipital parenchyma. For ADC(high), there was a positive correlation with gestational age for the frontal parenchyma (P=0.004), occipital parenchyma (P=0.02) and basal ganglia (P=0.03) but there was no correlation for the cerebellum.

CONCLUSIONS

DWI b0 values decreased in the left and right basal ganglia, cerebellar hemisphere, frontal parenchyma and occipital parenchyma between 17 and 37 weeks of gestation and ADC(avg) values increased in two out of four cerebral regions. It remains to be determined to what extent these observations differ in fetuses with suspicion of brain anomalies and whether such measurements will be useful and more predictive of outcome compared with standard MRI sequences.

Encephalitis following Mycoplasma pneumonia (2007: 6b)

We report an unusual case concerning encephalitis following Mycoplasma pneumonia. This interpretation corner case showed an unusual pattern of lesion distribution, resembling primary nervous system angiitis. The distribution of the lesions according to the perivascular spaces suggests a predominant leptomeningeal infiltration.

Cerebral ischemia after filter-protected carotid artery stenting is common and cannot be predicted by the presence of substantial amount of debris captured by the filter device

PURPOSE

Protected carotid artery stent placement is currently under clinical evaluation as a potential alternative to carotid endarterectomy. The current study was undertaken to determine the incidence of new ischemic lesions found on diffusion-weighted MR imaging (DWI) in nonselected patients after protected carotid artery stent placement using a filter device and to determine the potential relationship between these new ischemic lesions and the presence or absence of a clear amount of debris captured by the neuroprotection filter device.

MATERIALS AND METHODS

A nonrandomized cohort of 52 patients (40 men, 12 women) presenting with carotid occlusive disease underwent protected carotid artery stent placement using a filter device. DWI obtained 1 day before stent placement was compared with that obtained 1 day after stent placement. In addition, the macroscopic and microscopic analysis of debris captured by the filter device during the carotid stent placement procedure was assessed.

RESULTS

Neuroprotected carotid stent placement was technically successful in all 53 procedures but was complicated by a transient ischemic attack in 3 patients (5.6%). In 22 patients (41.5%), new ischemic lesions were found on DWI, and in 21 filter devices (39.6%), a substantial amount of atheromatous plaque and/or fibrin was found. No clear relationship between the presence of debris captured by the filter device and new lesions detected by DWI was found (P = .087; odds ratio 3.067).

CONCLUSION

Neuroprotected carotid artery stent placement will not avoid silent cerebral ischemia. Systematic microscopic analysis of debris captured by the filter device has no predictive value for potential cerebral ischemia after carotid artery stent placement.

Surgery and adjuvant dendritic cell-based tumour vaccination for patients with relapsed malignant glioma, a feasibility study

Patients with relapsed malignant glioma have a poor prognosis. We developed a strategy of vaccination using autologous mature dendritic cells loaded with autologous tumour homogenate. In total, 12 patients with a median age of 36 years (range: 11–78) were treated. All had relapsing malignant glioma. After surgery, vaccines were given at weeks 1 and 3, and later every 4 weeks. A median of 5 (range: 2–7) vaccines was given. There were no serious adverse events except in one patient with gross residual tumour prior to vaccination, who repetitively developed vaccine-related peritumoral oedema. Minor toxicities were recorded in four out of 12 patients. In six patients with postoperative residual tumour, vaccination induced one stable disease during 8 weeks, and one partial response. Two of six patients with complete resection are in CCR for 3 years. Tumour vaccination for patients with relapsed malignant glioma is feasible and likely beneficial for patients with minimal residual tumour burden.

Multiple vertebral fluid-fluid levels

We present a case of multiple vertebral metastases, with multiple fluid-fluid levels, from a moderately to poorly differentiated carcinoma of unknown origin. We suggest that fluid-fluid levels in multiple vertebral lesions are highly suggestive of bone metastases.

Fetal trauma: brain imaging in four neonates

The purpose of this paper is to describe brain pathology in neonates after major traffic trauma in utero during the third trimester. Our patient cohort consisted of four neonates born by emergency cesarean section after car accident in the third trimester of pregnancy. The median gestational age ( n=4) was 36 weeks (range: 30-38). Immediate post-natal and follow-up brain imaging consisted of cranial ultrasound ( n=4), computed tomography (CT) ( n=1) and post-mortem magnetic resonance imaging (MRI) ( n=1). Pathology findings were correlated with the imaging findings ( n=3). Cranial ultrasound demonstrated a huge subarachnoidal hemorrhage ( n=1), subdural hematoma ( n=1), brain edema with inversion of the diastolic flow ( n=1) and severe ischemic changes ( n=1). In one case, CT demonstrated the presence and extension of the subarachnoidal hemorrhage, a parietal fracture and a limited intraventricular hemorrhage. Cerebellar hemorrhage and a small cerebral frontal contusion were seen on post-mortem MRI in a child with a major subarachnoidal hemorrhage on ultrasound. None of these four children survived (three children died within 2 days and one child died after 1 month). Blunt abdominal trauma during pregnancy can cause fetal cranial injury. In our cases, skull fracture, intracranial hemorrhage and hypoxic-ischemic encephalopathy were encountered.

MRI findings in acute cerebellitis

Acute cerebellitis is an inflammatory process involving the cerebellum. We report the clinical, CT and MRI features of four cases and a review of the literature. Bilateral diffuse hemispheric abnormalities represent the most common imaging presentations. Our observations demonstrate the various imaging appearances of acute cerebellitis. Simultaneous involvement of both hemispheres and the vermis has not been reported previously. The development of cerebellar atrophy following an initial normal MR imaging examination is also a new finding. In atypical clinical presentation, MR imaging can lead to the diagnosis. MR imaging findings have, however, no prognostic value.

A case of hemiparesis associated with cranial nerve lesions due to intravascular lymphomatosis(2003:4b)

Intravascular lymphomatosis is a rare variant of non-Hodgkin's lymphoma with an unusual predilection for the central nervous system. Most cases are not diagnosed until postmortem because of variable clinical presentation and non-specific laboratory findings. We studied a 41-year-old lady who presented with progressive neurological symptoms. MR showed multifocal grey and white matter lesions. Brain biopsy showed an intravascular lymphoma of the B-cell lineage. This report illustrates the ischaemic origin of the radiological lesions, as they are all hyperintense on the diffusion-weighted images. This has, to our knowledge, never been published before. MR did not show any enhancement after intravenous Gadolinium-DTPA (parenchymal or meningeal)which is a very uncommon finding in this entity. Intravascular lymphomatosis should be taken into account in the differential diagnosis of repeated cerebral ischemia of unclear aetiology.

The value of fast MR imaging as an adjunct to ultrasound in prenatal diagnosis

The aim of this study was to evaluate the role of MR imaging of the fetus to improve sonographic prenatal diagnosis of congenital anomalies. In 40 fetuses (not consecutive cases) with an abnormality diagnosed with ultrasound, additional MR imaging was performed. The basic sequence was a T2-weighted single-shot half Fourier (HASTE) technique. Head, neck, spinal, thoracic, urogenital, and abdominal fetal pathologies were found. This retrospective, observational study compared MR imaging findings with ultrasonographic findings regarding detection, topography, and etiology of the pathology. The MR findings were evaluated as superior, equal to, or inferior compared with US, in consent with the referring gynecologists. The role of these findings in relation to pregnancy management was studied and compared with postnatal follow-up in 30 of 40 babies. Fetal MRI technique was successful in 36 of 39 examinations and provided additional information in 21 of 40 fetuses (one twin pregnancy with two members to evaluate). More precise anatomy and location of fetal pathology (20 of 40 cases) and additional etiologic information (8 of 40 cases) were substantial advantages in cerebrospinal abnormalities [ventriculomegaly, encephalocele, vein of Galen malformation, callosal malformations, meningo(myelo)cele], in retroperitoneal abnormalities (lymphangioma, renal agenesis, multicystic renal dysplasia), and in neck/thoracic pathology [cervical cystic teratoma, congenital hernia diaphragmatica, congenital cystic adenomatoid lung malformation (CCAM)]. This improved parental counseling and pregnancy management in 15 pregnancies. In 3 cases, prenatal MRI findings did not correlate with prenatal ultrasonographic findings or neonatal diagnosis. The MRI provided a more detailed description and insight into fetal anatomy, pathology, and etiology in the vast majority of these selected cases. This improved prenatal parental counseling and postnatal therapeutic planning.

Abnormalities of cerebellar foliation and fissuration: classification, neurogenetics and clinicoradiological correlations

Several genes have been found to influence the different cells involved in the processes of foliation and fissuration in the mouse and rat cerebellum. In the light of these new concepts and on the basis of the imaging findings in 42 patients, a classification is proposed for abnormalities of foliation and fissuration. On the basis of recent genetic and experimental evidence on mechanisms which control the origin of the cerebellum, it is suggested that abnormalities of foliation and fissuration form a single group, with a spectrum of severity. Some patients have only abnormal fissuration of the anterior lobe (type 1a) and others additional dysplasia of the anterior and part of the posterior lobe (type 1b). Extension of abnormalities into the hemispheres is often seen in the latter group. A second group has vermian and hemisphere abnormalities (type 2). In addition to the malformation of the anterior lobe of the vermis, three different hemispheric lesions can be seen in this group: cortical dysgenesis, hypertrophy of the cerebellar cortex, and malorientation of the folia. The mild abnormalities (type 1a) can be considered an incidental observation without clinical relevance. The moderate and severe cerebellar anomalies (type 1b and 2) are always associated with cerebellar symptoms and/or signs.

Spontaneous regression of an intraspinal disc cyst

We present a patient with a so-called disc cyst. Its location in the ventrolateral epidural space and its communication with the herniated disc are clearly shown. The disc cyst developed rapidly and regressed spontaneously. This observation, which has not been reported until now, appears to support focal degeneration with cyst formation as the pathogenesis.

Familial temporal lobe epilepsy with febrile seizures

Described are the clinical, EEG, MR, and genetic characteristics of 106 members of a family with autosomal dominant temporal lobe epilepsy (TLE) and febrile seizures (FS), with 22 affected individuals. Eleven patients had a history of FS, and 10 patients had TLE. EEG showed epileptic activity in five. None had hippocampal sclerosis. There was no evidence for linkage to 13 candidate loci. This large family with autosomal dominant TLE has a distinct phenotype and shows no linkage to known candidate regions for familial partial epilepsy and FS.

Cranial imaging in child abuse

Serious head injury in children less than 2 years old is often the result of child abuse. The role of the different neuroimaging modalities in child abuse is reviewed. Skull X-ray and cranial CT are mandatory. Repeat or serial imaging may be necessary and brain MR imaging may contribute to the diagnostic work-up, particularly in the absence of characteristic CT findings. The radiologist plays an important role in accurately identifying non-accidental cranial trauma. The clinical presentation can be non-specific or misleading. The possibility should be considered of a combined mechanism, i.e., an underlying condition with superimposed trauma. In this context, the radiologist is in the front line to suggest the possibility of child abuse. It is therefore important to know the spectrum of, sometimes subtle, imaging findings one may encounter. Ophthalmological examination is of the greatest importance and is discussed here, because the combination of retinal hemorrhages and subdural hematoma is very suggestive of non-accidental cranial trauma.

Intermediate short-term outcomes after brain computed tomography and magnetic resonance imaging in neurology outpatients

OBJECTIVE

The purpose of this study was to assess and compare the impact of magnetic resonance imaging (MIR) and computed tomography (CT) on diagnostic and therapeutic decision making, taking into account the real cost of both techniques at the authors' institution.

METHOD

Brain CT and routine and rapid MRI were compared, and case files were prepared with either the CT or the MRI findings. These files were separately presented to a neurologist, and different questions were asked about further management. The real cost of CT and MRI was calculated. A questionnaire was sent to the patients 3 months after imaging.

RESULTS

More lesions were detected on MRI than on CT Routine and rapid AIRI were comparable. The analysis of the CT case files revealed an additional request for MRl in 33% of the patients. An analysis of the MRI case files revealed that 20% more technical examinations were requested after MRI than after CT In the majority of the patients (90%), neuroimaging had no impact on therapy except by means of reassurance of the physician. The scan was considered useful for therapeutic planning by excluding the presence of a space-occupying lesion. The real cost of the MP! strategy was 9% higher than that of the CT strategy.

CONCLUSION

In this patient population, neuroimaging was normal in the majority of the patients. Undergoing an imaging examination was of benefit to the patients and improved their sense of well-being mainly by the reassurance they experienced, as reported by 91% of the patients. At the authors' institution, the real cost of MMI in this patient population was only slightly higher than the real cost of CT The statistical analysis favors the use of MRI as a 1st imaging examination.

Lhermitte-Duclos disease is a clinical manifestation of Cowden's syndrome

BACKGROUND

Lhermitte-Duclos disease (LDD) is a hamartomatous overgrowth of cerebellar ganglion cells, which replace granular cells and Purkinje cells. In recent years several cases involving the association between LDD and Cowden's syndrome (CS), an autosomal dominant condition characterized by multiple hamartomas and neoplastic lesions in skin and internal organs, have been reported.

METHODS

We reviewed the medical records and imaging studies of six patients with LDD who were treated at our institution, and we looked at other possible symptoms of CS.

RESULTS

Other clinical findings suggestive of CS were apparent in five patients: These included mucocutaneous lesions, acral keratosis, thyroid adenoma, fibrocystic disease, ovarian cyst, intestinal polyposis, and arteriovenous malformation. Only in the youngest patient, a 5-year-old boy, were no cutaneous or other signs found, despite extensive clinical and ultrasound examination.

CONCLUSION

Our observations strengthen the hypothesis that LDD is a neurological manifestation of CS. Patients with LDD should receive a thorough dermatological and systemic screening, because some of the lesions (breast, etc...) can develop into malignant tumors.

Interobserver variations in gross tumor volume delineation of brain tumors on computed tomography and impact of magnetic resonance imaging

PURPOSE

(1) To assess the interobserver variability of brain tumor delineation on computed tomography (CT). (2) To assess the impact of the addition of magnetic resonance imaging (MRI) information.

METHODS

Nine physicians were asked to delineate the gross tumor volume (GTV) of five patients with supratentorial inoperable brain tumors on CT scans and 2 weeks (or more) later on MRIs. The delineations were performed on a computer screen. During delineation on MRI, the registered CT images (without delineation) were displayed on the screen (MRI+CT).

RESULTS

A high interobserver variability in GTV delineation on CT is found: the ratio of the largest to the smallest defined volumes varies for the five patients by factors of resp. 2.8, 1.8, 1.8, 1.9 and 1.7. The interobserver variability is as large on MRI+CT as on CT alone (ratio largest/smallest volume: 2.4, 1.7, 1.9, 2.7 and 1.5). Volumes delineated on MRI+CT (mean: 69.6 cm(3)) are larger than on CT alone (mean: 59.5 cm(3)). Residual volumes (volume delineated on one image modality but not on the other) are >0 for CT alone and for MRI+CT.

CONCLUSIONS

A large interobserver variability in GTV delineation of brain tumors is demonstrated. The addition of MRI to CT does not reduce interobserver variability. GTVs delineated on MRI+CT are larger than on CT alone, but some volumes are delineated on CT and not on MRI. Therefore, a combination of the two image modalities is recommended for brain tumor delineation for treatment planning.