Limited dorsal myeloschisis without extradural stalk continuity to coexisting congenital dermal sinus.

Limited dorsal myeloschisis (LDM) is characterized by a fibroneural tethering stalk linking the skin lesion to the underlying spinal cord. LDM without an extradural stalk is rare. A full-term boy was noted at birth to have a dimple in the upper back (dorsal skin of the lower thoracic region). Computed tomographic scan showed spina bifida at the T9-12 vertebral level and osteochondral tissue at the T10 level. Magnetic resonance imaging (MRI) demonstrated a tiny dorsal lipoma at the T8 vertebral level, but the intradural tethering tract was not apparent. At 18 days of age, the congenital dermal sinus (CDS) tract started from the dimple and terminated at the osteochondral tissue, without continuity of the dura mater, and the osteochondral tissues were resected. At age 2 years 8 months, he developed spastic paresis of the right foot. On MRI, the tethering tract from the dorsal lipoma became apparent. During the second surgery at age 2 years 11 months, the intradural stalk started from the dorsal lipoma and joined the inner surface of the dura mater was untethering from the cord. Postoperatively, right spastic paresis was improved. Histological examination of the intradural stalk revealed the distribution of S100-immunopositive peripheral nerve fibers, which is one of the histopathological hallmarks of LDM. We speculated that the extradural stalk with coexisting CDS originally linked from the skin lesion subsequently regressed and was replaced by fibroadipose tissue with osteochondral tissue migration. Intradural exploration should always be seriously considered in these disorders of persisting neurocutaneous connection.

Multifaceted structural magnetic resonance imaging findings in demented patients with pathologically confirmed TDP-43 proteinopathy.

This short report clarifies the heterogeneity of structural magnetic resonance imaging (MRI) findings in seven demented patients due to pathologically accumulated TAR DNA-binding protein-43 (TDP-43) protein using visual analyses including visual rating scales (i.e., global cortical atrophy and medial temporal atrophy scales). In addition to the well-known frontotemporal lobar atrophy, structural MRI has revealed multifaceted imaging findings including asymmetric atrophy of the frontoparietal lobe and cerebral peduncle, midbrain atrophy, and localized or diffuse white matter T2 hyperintensity. Understanding of these multifaceted neuroimaging findings is important for the precise antemortem diagnosis of TDP-43 proteinopathy.

Sudden death in a case of megalencephaly capillary malformation associated with a de novo mutation in AKT3.

INTRODUCTION: Megalencephaly capillary malformation (MCAP) is a syndrome involving brain overgrowth, characterized by megalencephaly, capillary malformations, asymmetric growth, polymicrogyria, polydactyly, and syndactyly. Cerebellar tonsillar herniation (CTH) and ventriculomegaly are also observed in over half the patients with this syndrome. Early sudden death has been reported in MCAP, but its causes and the surgical strategies for its prevention remain unclear. CASE REPORT: Here, we report on a patient with MCAP who died suddenly at 5 months of age. He presented with progressive macrocephaly and hypotonia. MRI performed at 4 months of age showed tight posterior fossa, bilateral perisylvian polymicrogyria, enlargement of the straight sinus, and a thickened corpus callosum. However, since the patient did not exhibit capillary malformation, polydactyly, or syndactyly, a definitive diagnosis of MCAP could not be made. He died suddenly while asleep at home 1 month later. The sudden death of MCAP patients was previously attributed to CTH, convulsion, or arrhythmia. In this case, progressive cerebellar enlargement appeared to be the underlying cause. After the patient's death, using his preserved DNA, a missense mutation in the AKT3 gene was identified. Vakt murine thymoma viral oncogene homologue (AKT) is a serine-threonine kinase that functions in the mammalian target of rapamycin (mTOR) pathway and plays an important role in cell proliferation. CONCLUSION: Accurate early diagnosis, including imaging and genetic analyses, and the recognition and treatment of critical conditions are required to prevent the sudden death of patients with MCAP.

Magnetic resonance imaging volumetry and clinical analysis of epilepsy patients with unilateral hippocampal abnormality.

BACKGROUND: In order to clarify the correlation between morphological characteristics and clinical features in epilepsy patients with unilateral hippocampal abnormality, morphological and morphometric magnetic resonance imaging studies were performed. METHODS: We selected a series of childhood-onset epilepsy patients with unilateral hippocampal abnormality. The volume of hippocampal formation and anterior temporal lobe were measured, and the hippocampal morphology was compared with their clinical features. The morphological characteristics of the hippocampal formation were classified into three groups: group I, diffuse and severe volume reduction of the hippocampal formation and anterior temporal lobe with abnormal signal; group II, focal atrophy or focal abnormal signal in the hippocampal formation; and group III, no significant volume reduction but an enlargement of the temporal horn. RESULTS: All of the patients in group I had a history of status epilepticus in infancy. Temporal lobe epilepsy (TLE) was found in three of four patients. Group II contained TLE in three and frontal lobe epilepsy in one. One patient with intractable TLE had a history of status epilepticus in infancy. Group III contained miscellaneous epilepsies, including benign partial epilepsy with centro-temporal spikes in three of seven patients. Five patients in group III showed some characteristic features of hippocampal malrotation, which refers to incomplete hippocampal infolding. CONCLUSIONS: Diffuse and severe volume reduction of the hippocampal formation and anterior temporal lobe with unilateral hippocampal sclerosis was strongly associated with status epilepticus in infancy. Both hippocampal sclerosis and hippocampal malrotation suggest significant roles in the pathogenesis of epilepsy.

Differences in CT perfusion maps generated by different commercial software: quantitative analysis by using identical source data of acute stroke patients.

PURPOSE: To examine the variability in the qualitative and quantitative results of computed tomographic (CT) perfusion imaging generated from identical source data of stroke patients by using commercially available software programs provided by various CT manufacturers. MATERIALS AND METHODS: Institutional review board approval and informed consent were obtained. CT perfusion imaging data of 10 stroke patients were postprocessed by using five commercial software packages, each of which had a different algorithm: singular-value decomposition (SVD), maximum slope (MS), inverse filter (IF), box modulation transfer function (bMTF), and by using custom-made original software with standard (sSVD) and block-circulant (bSVD) SVD methods. Areas showing abnormalities in cerebral blood flow (CBF), mean transit time (MTT), and cerebral blood volume (CBV) were compared with each other and with the final infarct areas. Differences among the ratios of quantitative values in the final infarct areas and those in the unaffected side were also examined. RESULTS: The areas with CBF or MTT abnormalities and the ratios of these values significantly varied among software, while those of CBV were stable. The areas with CBF or MTT abnormalities analyzed by using SVD or bMTF corresponded to those obtained with delay-sensitive sSVD, but overestimated the final infarct area. The values obtained from software by using MS or IF corresponded well with those obtained from the delay-insensitive bSVD and the final infarct area. Given the similarities between CBF and MTT, all software were separated in two groups (ie, sSVD and bSVD). The ratios of CBF or MTTs correlated well within both groups, but not across them. CONCLUSION: CT perfusion imaging maps were significantly different among commercial software even when using identical source data, presumably because of differences in tracer-delay sensitivity.

Two pediatric cases of epidural hematoma in the posterior fossa with extension along the sigmoid sinus groove: MR evaluation.

To discuss the computed tomography (CT) and magnetic resonance (MR) findings of posterior fossa epidural hematoma (PFEDH) mimicking sinus thrombosis, we present two pediatric cases with the PFEDH extending along the sigmoid sinus groove evaluated by MR imaging (MRI) and MR venography (MRV). T2-weighted coronal MRI can diagnose both patency of the sigmoid sinus and epidural hematoma extending along the sinus groove. Phase-contrast MRV (PC-MRV) is also useful to evaluate the flow state in the dural sinuses but it should be diagnosed carefully whether low visualization of the dural sinus means only functional flow impairment or organized occlusion due to thrombus. To avoid an unnecessary anticoagulant therapy that may worsen epidural hematoma, it is important to recognize the pitfall that PFEDH extending along the sinus groove is easy to misdiagnose for a dural sinus thrombosis.

Infantile macrocephaly and multiple subcutaneous lipomas diagnosed with PTEN hamartoma tumor syndrome: A case report.

A heterozygous loss-of-function mutation of the PTEN gene, one of the tumor suppressor genes, causes a wide variety of disorders, ranging from macrocephaly/autism syndrome to PTEN hamartoma tumor syndrome, including Cowden disease that causes thyroid and breast cancer mainly in the adolescence and young adult generation. An 8-month-old male infant with simple macrocephaly developed a café-au-lait spot and two subcutaneous tumors at the age of 1 year. One of the tumors developed rapidly was resected at the age of 1 year and 9 months and identified as benign lipoma. From the age of 2 years, the patient often threw a tantrum. At the age of 2 years and 9 months, a pathogenic germline mutation was identified in the PTEN gene (NM_000314.7), c.195C>A, p.Y65* in the form of a heterozygous germline variant. Developmental delay was noted but no tumors were found in the thyroid gland and breasts. Immunohistochemistry for PTEN in the resected lipoma demonstrated that the PTEN expression pattern was similar to that in a subcutaneous adipose tissue from a normal subject, suggesting that two-hit was not likely involved in the rapid growth of this lipoma. At the age of 5 years, the patient was diagnosed with autism spectrum disorders with moderate developmental delay. A long-term follow-up is underway to examine developmental changes in psychomotor disorders and possible tumor formation.

Management of pilomyxoid astrocytomas: our experience.

BACKGROUND: Pilomyxoid astrocytoma (PMA) shows a higher rate of recurrence and cerebrospinal fluid (CSF) dissemination than does pilocytic astrocytoma (PA). In this article, we discuss the treatment of PMA. MATERIALS AND METHODS: Between 1992 and 2007, the authors treated 5 patients. Two of these were male, three female. Their ages ranged from 3 months to 11 years. RESULTS: Three patients showed CSF dissemination on the initial radiographic examination. All patients received chemotherapy; the most commonly used combination drugs were cisplatin (CDDP)/carboplatin (CBDCA) and etoposide. When these drugs were unsuccessful, they were changed or other drugs added to the combination. After chemotherapy, four patients showed remarkable tumor regression. Nevertheless, one patient died 22 months after initial diagnosis, due to tumor progression. CONCLUSION: While our series was limited to a small number of patients, we have a positive impression of the value of chemotherapy. Even if initial chemotherapy is ineffective, we recommend continued CDDP/CBDCA-based chemotherapy with new drug combinations.

Functional connectivity change between posterior cingulate cortex and ventral attention network relates to the impairment of orientation for time in Alzheimer's disease patients.

Alzheimer's disease (AD) patients exhibit various cognitive dysfunctions, including impairment of orientation for time (OT). The brain regions underlying OT impairment remain to be elucidated. A previous single-photon emission computed tomography study has indicated hypoperfusion of the posterior cingulate cortex (PCC) in relation to deterioration of OT. In this study, we investigated whole brain functional connectivity changes of PCC using resting-state functional magnetic resonance imaging. Voxel-based functional connectivity with PCC was analyzed in OT-poor or OT-good AD patients, classified according to the mean OT scores of the Mini-Mental State Examination subscale. The connectivities of dorsal frontal lobe, and lateral parietal and lateral temporal lobes with PCC in the right hemisphere were reduced in the OT-poor AD group compared with the OT-good AD group. A subtraction connectivity map of OT score differences (OT-good minus OT-poor) revealed the right middle temporal gyrus near the temporo-parietal junction as a significantly connected region with PCC. These results suggest that the right posterior part of the middle temporal gyrus may play an important role in OT in conjunction with PCC, and that disconnection between PCC and the right ventral attention network may cause OT disturbance in AD patients.

Congenital medulloblastoma with atypical MRI appearance.

A 13-day-old female infant was admitted with hydrocephalus that had been diagnosed on prenatal ultrasound at 33 weeks' gestation. She was delivered by Caesarean section at 34 weeks with an Apgar score of 10. On admission, she weighed 2,103 g. The head circumference was 32.3 cm, and the fontanelle was tense. T(1)- and T(2)-weighted MR images revealed an isointense mass occupying the fourth ventricle with multiple cysts in the vermis. The mass was not enhanced after gadolinium administration. CT showed no definite calcification in the lesion. Preoperatively, vermian tumors, including medulloblastoma, ependymoma, astrocytoma, and hamartomas, were considered in the differential diagnosis. Hamartoma was strongly suspected due to the lack of enhancement on MRI. After a suboccipital midline craniotomy, subtotal resection of a soft grayish tumor with areas of hematoma was carried out. The pathological diagnosis was medulloblastoma. Despite chemotherapy, CSF dissemination resulted in death at 11 months. We report this case of congenital medulloblastoma with atypical MRI findings and discuss the clinical characteristics of this lesion.

Migrainous infarction in an adult: evaluation with serial diffusion-weighted images and cerebral blood flow studies.

We report the case of a 64-year-old man with migrainous infarction, giving special attention to chronological changes in neuroimaging findings. Five days after the onset, diffusion-weighted imaging showed slightly high intensity, and the apparent diffusion coefficient map showed increased diffusion in the right occipital lobe, which indicated vasogenic edema. Perfusion magnetic resonance imaging (MRI) and MR angiography demonstrated hyperperfusion of the ipsilateral hemisphere. Follow-up MRI showed irreversible brain damage. These images may reflect chronological changes in cerebral edema due to prolonged hyperperfusion with migraine.

[Wernicke encephalopathy in a chronic peritoneal dialysis patient--correlation between diffusion MR and pathological findings].

Wernicke encephalopathy (WE) is a neurologic disorder caused by a nutritional deficiency of thiamine. Since the lesion in WE consists of brain edema, diffusion weighted imaging (DWI) is quite useful for detecting the pathologic changes in WE, and can differentiate between reversible extracellular (vasogenic) and irreversible cellular (cytotoxic) edema. We report here a 16-year-old man with WE who had been treated with continuous ambulatory peritoneal dialysis for chronic renal failure. He underwent repeated DWI and postmortem examination. DWI, which was performed 8 days after the onset of neurological symptoms, showed high intensity areas in the bilateral thalami, mammillary bodies, tegmentum mesencephali and pons. Apparent diffusion coefficient (ADC) map also showed slightly high intensity in the periaqueductal gray matter and pons, which indicated extracellular edema. On the other hand, ADC map showed low intensity areas in the most medial part of the thalami and marginal area of the tegmentum mesencephali, which indicated cellular edema. In the postmortem examination, the areas that showed low intensity on ADC map exhibited mild neuronal loss. Based on the correlation between the DWI and pathologic findings, the cytotoxic edema of the bilateral medial thalami and marginal tegmentum mesencephali in this patient was considered to be glial cell edema which may protect against neuronal cell damage.

Preoperative extracranial carotid artery examination with ultrasonography in patients undergoing coronary artery bypass grafting in Japan.

PURPOSE: We investigated the incidence, degree, and plaque characteristics of extracranial carotid stenosis with carotid ultrasonography (CUS) in patients undergoing coronary artery bypass grafting (CABG). MATERIALS AND METHODS: Preoperative CUS was performed on 221 patients (442 carotid arteries) undergoing CABG. The degree of extracranial carotid stenosis was calculated based on the area stenosis, and it was classified into six grades as follows: grade (G) 0, G1 (1%-29%), G2 (30%-49%), G3 (50%-69%), G4 (70%-99%), and G5 (occlusion). RESULTS: The incidence of G4 was 4.1% and G5 1.6%. There were 48 arteries rated G3 or G4. Hypoechoic plaque was detected in 28 of the 48 arteries (58%), and heterogeneous plaque was detected in 37 arteries (73%). Ulcerative plaque was detected in 27 arteries (56%); when comparing the G3 and G4 groups, ulcerative plaque was found more frequently in G4 than in G3 (14/18 vs 13/30 arteries, P < 0.02). CONCLUSION: Our study demonstrated that patients undergoing CABG with extracranial severe carotid stenosis tend to have heterogeneous, hypoechoic, and ulcerative plaque. We believe that preoperative CUS should be used to evaluate the plaque characteristics of extracranial carotid stenosis.

Midline cystic malformations of the brain: imaging diagnosis and classification based on embryologic analysis.

This article describes a classification and imaging diagnosis of intracranial midline cystic malformations based on neuroembryologic analysis. Midline cystic malformations are classified into two categories from an embryologic point of view. In one category, the cyst represents expansion of the roof plate of the brain vesicle, and in the other the cyst consists of extraaxial structures such as an arachnoid membrane or migrating ependymal cells. Infratentorial cysts, such as the Dandy-Walker cyst or Blake's pouch cyst, and supratentorial cysts, such as a communicating interhemispheric cyst with callosal agenesis or a dorsal cyst with holoprosencephaly, are included in the first category. Infratentorial arachnoid cavities, such as the arachnoid cyst, arachnoid pouch, and mega cisterna magna, are in the second category. Noncommunicating interhemispheric cysts, such as interhemispheric arachnoid cyst or ependymal cyst, with callosal agenesis are also in the second category. A careful review of embryologic development is essential for understanding these midline cysts and for making a more accurate radiologic diagnosis.

[Serial MRI findings of intracranial tuberculomas: a case report and review of the literature].

Intracranial tuberculoma is an infectious disorder, occurring with or without tuberculous meningitis. Although intracranial tuberculoma is rare in developed countries, its frequency has increased in recent years in association with aging and immunocompromised hosts. Because of the low sensitivity of Mycobacterium tuberculosis cultures or of DNA detection from cerebrospinal fluid, diagnosis of intracranial tuberculoma is often difficult. Conventional magnetic resonance (MR) imaging of the tuberculoma yields variable results and is indistinct from other inflammatory lesions or brain tumors. We report the case of a 74-year-old woman with progressive neurologic deterioration. MR imaging of the brain showed multiple ring-like enhancing lesions in the supra- and infra-tentorial regions, mimicking multiple metastatic brain tumors. Diffusion-weighted imaging (DWI) of the brain showed homogeneous high signals in each lesion. A cavity in the lung suggested systemic involvement of tuberculosis. Despite extensive examination, tuberculosis could not be detected. Nevertheless, anti-tuberculosis treatment was administered. The patient's neurologic condition initially deteriorated for 4 weeks, then gradually improved. MRI showed marked improvement of the lesions after anti-tuberculosis treatment. Whereas conventional MRI is not specific in such cases, DWI might be useful for early assessment of intracranial tuberculosis.

[Two case mimicking cerebral tuberculoma in MRI diffusion weighted-images with difficult preoperative diagnosis].

Two cases with a high signal intensity core with laminar structure based on diffusion weighed-images (DWI) mimicking intracerebral tuberculoma were herein reported. Both patients were suspected to have pulmonary tuberculosis in their past history and/or based on chest X-ray findings. DWI demonstrated a high signal intensity core with laminar structure, thus suggesting the presence of an intracerebral tuberculoma. As initial therapy, both patients received anti-tuberculous drugs, however, their symptoms did not improve, and the lesions were observed to have increased in MRI. As a result, a biopsy was carried out to clarify the nature of the disease. A pathological examination showed the former to be a brain abscess while the latter was metastatic carcinoma. In such cases mimicking intracerbral tuberculoma based on DWI, anti-tuberculous drugs are first treatment of choice, however, a biopsy should be performed as early as possible if the medication dose not show a significant response.

A case of optic-nerve hypoplasia and anterior segment abnormality associated with facial cleft.

INTRODUCTION: The incidence of facial cleft is rare and ranges between 1.43 and 4.85 per 100,000 births. To date, there have been few reports of detailed ophthalmologic examinations performed in cases of facial cleft. Here, we report a case of optic-nerve hypoplasia and anterior segment abnormality associated with facial cleft. CASE REPORT: A 9-day-old female infant was delivered by cesarian section at 34 weeks of gestational age (the second baby of twins) and weighed 2,276 g upon presentation. She had a facial cleft and ectrodactyly at birth. Right eye-dominant blepharophimosis was obvious. Examination of the right eye revealed inferior corneal opacity with vascularization, downward corectopia, and optic-nerve hypoplasia. The corneal diameter was 8 mm in both eyes, and tonometry by use of a Tono-Pen(®) XL (Reichert Technologies, Depew, NY, USA) handheld applanation tonometer revealed that her intraocular pressure was 11-22 mmHg (Oculus Dexter) and 8 mmHg (Oculus Sinister). B-mode echo revealed no differences in axial length between her right and left eyes. When she was 15-16 months old, we attempted to examine her eyes before she underwent plastic surgery under general anesthesia. She had a small optic disc in both eyes and the right-eye disc was tilted. After undergoing canthotomy, gonioscopy and ultrasound biomicroscopy revealed that almost all directions were open except for the peripheral anterior synechia. Since magnetic resonance imaging revealed ventriculomegaly associated with an interhemispheric cyst at birth, a ventriculoperitoneal shunt was inserted at 12 days of age. At 25 months of age, her condition suddenly deteriorated due to occlusion of the ventricular shunt catheter, and she died 5 days later. In this patient, amniotic band syndrome was presumed to be the primary cause due to the clinical findings. CONCLUSION: We experienced a case of optic-nerve hypoplasia and anterior segment abnormality that occurred with facial cleft. The cause of these abnormalities is unclear, yet amniotic band syndrome is a possible candidate.

In vitro characterization of neurite extension using induced pluripotent stem cells derived from lissencephaly patients with TUBA1A missense mutations.

BACKGROUND: Lissencephaly, or smooth brain, is a severe congenital brain malformation that is thought to be associated with impaired neuronal migration during corticogenesis. However, the exact etiology of lissencephaly in humans remains unknown. Research on congenital diseases is limited by the shortage of clinically derived resources, especially for rare pediatric diseases. The research on lissencephaly is further limited because gyration in humans is more evolved than that in model animals such as mice. To overcome these limitations, we generated induced pluripotent stem cells (iPSCs) from the umbilical cord and peripheral blood of two lissencephaly patients with different clinical severities carrying alpha tubulin (TUBA1A) missense mutations (Patient A, p.N329S; Patient B, p.R264C). RESULTS: Neural progenitor cells were generated from these iPSCs (iPSC-NPCs) using SMAD signaling inhibitors. These iPSC-NPCs expressed TUBA1A at much higher levels than undifferentiated iPSCs and, like fetal NPCs, readily differentiated into neurons. Using these lissencephaly iPSC-NPCs, we showed that the neurons derived from the iPSCs obtained from Patient A but not those obtained from Patient B showed abnormal neurite extension, which correlated with the pathological severity in the brains of the patients. CONCLUSION: We established iPSCs derived from lissencephaly patients and successfully modeled one aspect of the pathogenesis of lissencephaly in vitro using iPSC-NPCs and iPSC-derived neurons. The iPSCs from patients with brain malformation diseases helped us understand the mechanism underlying rare diseases and human corticogenesis without the use of postmortem brains.

Differential expression of cytokines, chemokines and their receptors in follicular lymphoma and reactive follicular hyperplasia: assessment by complementary DNA microarray.

Follicular lymphoma (FL) is pathologically categorised as a low-grade B-cell lymphoma and histopathologically shows follicular proliferation of neoplastic B cells. In the neoplastic follicles of FL, the presence of T cells, macrophages and follicular dendritic cells (FDCs) suggests that these cells may promote a favourable environment for the growth of FL cells. Because FL cells are generally associated with FDCs, FDCs may be considered an important source of cytokines and chemokines. FDCs form the framework for germinal centres and also provide networks for nodules of FL. To evaluate the gene expression in neoplastic follicles of FL and reactive follicles of reactive follicular hyperplasia (RFH), we performed gene expression profiling of FL (n=5) and RFH (n=5) using complementary DNA (cDNA) microarray of cytokines/chemokines and their receptors. FL and RFH exhibited a diffuse down-regulated profile compared with normal peripheral blood cells, which were used as controls, although some genes displayed up-regulated profiles. Hierarchical clustering analysis separated FL and RFH into two distinct groups based on their gene expression profiles. FL cases exhibited significantly higher expression of interleukin 3 receptor alpha (IL-3Ralpha) than RFH. Immunohistochemically, neoplastic follicles of FL frequently expressed IL-3Ralpha, especially in FDCs, but not in FL cells. However, IL-3Ralpha expression was rare or weak in the reactive follicles of RFH. These findings suggest the importance of the micro-environment for FL cell growth. Further studies of cDNA microarray should provide new insight into the molecular pathology of FL and may allow the design of improved therapies.

Differential expression of chemokines, chemokine receptors, cytokines and cytokine receptors in diffuse large B cell malignant lymphoma.

Host immunity, particularly T cell immunity (Th1/Th2 balance), plays an important role in clinicopathological features of malignant disease. However, the T cell immunity has not been fully investigated in patients with lymphoid malignancies. Recent studies suggested the important role of dysregulation of the endogenous immune system in lymphomagenesis. The relationships between cytokines/chemokines and their receptors, are important in determining the selectivity of local immunity. To investigate differences in the endogenous immune system of diffuse large B cell lymphoma (DLBL), we performed gene expression profiling using cDNA microarrays of cytokines/chemokines and their receptors. We studied 5 cases each of primary central nervous system lymphomas (PCNSL), extranodal and nodal lymphomas. PCNSL exhibited diffuse down-regulated profiles, compared to normal peripheral blood lymphocytes. While extranodal and nodal lymphomas also exhibited diffuse down-regulated profiles, some genes displayed up-regulated profiles. Hierarchical clustering analysis separated PCNSL and extranodal lymphomas into distinct groups based on their gene expression profiles, as well as extranodal and nodal, but not PCNSL and nodal. PCNSL exhibited significantly lower expression of BLC/BCA-1 and CCR-3 (Th2 type), and higher expression of IL-8 and MIP-1beta (Th1 type) than extranodal lymphomas. Immunohistochemistry and RT-PCR revealed frequent CCR-3 and BLC/BCA-1 expression in extranodal lymphomas, compared with PCNSL. Our results provide new insights into the pathogenesis of each DLBL. A better understanding of the immune response in each DLBL could help in the design of novel therapeutic strategies based on cytokines/chemokines and their receptors.