Placental alkaline phosphatase levels in cerebrospinal fluid can have a decisive role in the differential diagnosis of intracranial germ cell tumors

OBJECTIVE

Placental alkaline phosphatase (PLAP) in CSF can provide a very high diagnostic value in cases of intracranial germ cell tumors (GCTs), especially in pure germinomas, to the level of not requiring histological confirmation. Unlike other tumor markers, reliable data analysis with respect to the diagnostic value of PLAP serum or CSF levels has not been available until now. This is the first systematic and comprehensive study examining the diagnostic value of CSF PLAP in patients with intracranial GCTs.

METHODS

From 2004 to 2014, 74 patients (average age 19.6 ± 10.6 years) with intracranial GCTs were evaluated using PLAP from their CSF and histological samples. Chemiluminescent enzyme immunoassay was utilized to measure CSF PLAP in the following tumor sites: pineal (n = 32), pituitary stalk, suprasellar (n = 16), basal ganglia (n = 15), intraventricular (n = 9), and cerebellar (n = 5) regions. In addition to classifying GCT cases, all patients underwent tumor biopsy for correlation with tumor marker data.

RESULTS

PLAP in combination with other tumor markers resulted in extremely high sensitivity and specificity of the diagnostic value of intracranial GCTs. Intracranial GCT cases were classified into 1) germinomas, both "pure" and syncytiotrophoblastic giant cell types (n = 38); 2) nongerminomatous GCTs, choriocarcinomas (n = 9) and teratomas (n = 4); and 3) nongerminomas, other kinds of tumors (n = 23). Consequently, all patients received chemoradiation therapy based on elevation of PLAP and the histopathological results. It was also speculated that the level of PLAP could show the amount of intracranial germ cell components of a GCT. PLAP was 100% upregulated in all intracranial germinoma cases. The absence of CSF PLAP proved that the tumor was not a germinoma.

CONCLUSIONS

The current study is the first systematic and comprehensive examination of the diagnostic value of the tumor marker PLAP in pediatric patients with intracranial GCT. Using the level of PLAP in CSF, we were able to detect the instances of intracranial germinoma with very high reliability, equivalent to a pathological diagnosis.

Primary Intracranial Malignant Melanoma with Extracranial Metastasis

We report a case of primary intracranial malignant melanoma (PIMM) with extracranial metastases. The patient was an 82-year-old woman diagnosed with PIMM under the left cerebellar tentorium. We performed a tumor resection followed by gamma knife surgery. An magnetic resonance imaging at 11 months after surgery showed a local intracranial recurrence. At 12 months, vertebral metastasis was suspected, and 2-[fluorine-18]-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (FDG-PET/CT) showed multiple extracranial metastases. She died at 13 months after surgery. Although extracranial metastases of PIMM are extremely rare, we should carefully follow up extracranial metastases together with intracranial ones, especially by FDG-PET/CT, even at an early asymptomatic stage.

[Two Cases of Primary Intracranial Solitary Fibrous Tumor:Genetic Examination of <i>NAB2-STAT6</i> Fusion and Its Association with Hemangiopericytoma]

Using whole exome and transcriptome sequencing, NAB2-STAT6 gene fusions have recently been identified in patients with solitary fibrous tumors (SFT). We report two cases of SFT in which NAB2-STAT6 fusions were identified. The patients were a 32-year-old man with a parasagittal tumor involving the superior sagittal sinus, and a 40-year-old man with a cerebellar convexity tumor partially involving the transverse sinus. Their tumors were gross totally resected and diagnosed to be SFT according to the following pathological findings:the tumors were composed of spindle cells with a patternless architecture, with prominent stromal collagen and staghorn vessels. An immunohistochemical study yielded positive results for CD34, CD99, and Bcl-2 and negative results for EMA, GFAP, and S100. The MIB-1 indexes were 13 and 7%, respectively. NAB2-STAT6 fusions were detected in both cases with a common fusion variant, NAB2ex6-STAT6ex16/17. We also identified NAB2-STAT6 fusions in two hemangiopericytomas diagnosed in the past with a common variant of NAB2ex6-STAT6ex16/17. These findings suggest that solitary fibrous tumor and hemangiopericytoma may be diagnosed based on the presence of NAB2-STAT6 fusion, and not classified separately because of the same genetic background.

Cranial molding helmet therapy and establishment of practical criteria for management in Asian infant positional head deformity

BACKGROUND

The growing number of infants with deformational plagiocephaly (DP) has raised clinical questions about which children, at what age, and how molding helmet therapy (MHT) should be performed especially in Japan.

METHODS

A total of 1,011 Japanese pediatric head deformity infants had undergone MHT after being diagnosed with non-synostotic DP. Three ratios of left to right comparison (anterior, posterior, and overall) were created and analyzed comparing age of starting treatment, helmet wearing period, and severity of skull deformity before with after MHT.

RESULTS

The averages of head symmetry ratios after treatment in all groups (for the occipital region) showed apparent improvement; t(930) = -60.86, p = 0.000. (t(932) = -57.8, p = 0.000.) In the "severe" deformation group, the earlier the treatment was started, the higher symmetry ratio recovery was obtained. Treatment was especially effective when started in 4-month-old infants. In contrast to the "severe" group, the "mild" deformation group showed that MHT was most effective if treatment started before 6 months of age. Again, the earlier the treatment was started, the higher symmetry ratio was achieved, but compared to the "severe" group, it had a modest effect when treatment was started in infants older than 8 months.

CONCLUSION

This is the first large-scale molding helmet study reporting the method and efficacy in Japanese infants. It demonstrated that despite the structural and physiological differences from infants of other races, molding helmet therapy is effective in Asian-born infants, provided that intervention timing and recognition conditions are met.

[A case of cavernous sinus epidermoid: anatomical classification and surgical approach]

Epidermoid rarely appears in the cavernous sinus. We encountered a 41-year-old man with left abducens nerve palsy. A round-shaped, low-density lesion on CT was located lateral to the left cavernous sinus with a compressed and thinned lateral wall of the sphenoid sinus. We could not identify cranial nerves in the cavernous sinus, which was found to be packed with a non-enhanced, high-intensity tumor on both T1 and T2 MRI. Part of the tumor capsule and its pearly contents were removed with an intradural subtemporal approach, and an inner membranous layer with cranial nerves and a tumor capsule were seen at the bottom of the tumor cavity. Postoperatively, complete cure was achieved. Reviewing similar cases, we found 18 cavernous sinus epidermoids:extracavernous type in 5;interdural in 10;and intracavernous in 3. The interdural type could be further divided into two subtypes:superficial cavernous sinus and inner membranous types. The present case belongs to the former. Frontotemporal and subtemporal procedures via both intra- and extradural approaches are relatively safe for lesions except for the intracavernous type, because cranial nerves are not located in the lateral wall of the tumor. MRI provides more useful information on cranial nerves and aid in choosing a better treatment strategy.

[A case of cerebral infarction treated with tissue-plasminogen activator exhibiting prolonged cerebral edema for more than 1 month]

A 62-year-old man with hypertension and diabetes mellitus controlled by medication suddenly noticed slight hemiparesis and was admitted to our hospital. Tissue-plasminogen activator (t-PA) was administered as his NIHSS was 6 and there were no contraindications. His symptoms completely resolved after t-PA injection. He was discharged on Day 9 without neurological deficits despite minor bleeding being detected in a small, low-density area in the right post-central region on CT. However, the hemiparesis gradually recurred subsequently and the low-density area had increased. He was readmitted on Day 38 due to deterioration of symptoms and enhanced CT imaging exhibited a large, low-density area in the central parasagittal region with enhancement was seen. An open biopsy was performed on Day 52 for diagnostic purposes. Histology demonstrated increased small vessels surrounded by many non-specific inflammatory cells and abundant reactive astrocytes. To date, reports of prolonged cerebral edema lasting more than 1 month after cerebral infarction are rare. This condition may be due to angiogenesis induced by t-PA. Another reason may have been the location, i.e., the parasagittal region, which is the most common area for severe cerebral edema after gamma knife surgery.

A highly sensitive and specific chemiluminescent enzyme immunoassay for placental alkaline phosphatase in the cerebrospinal fluid of patients with intracranial germinomas

BACKGROUND

Placental alkaline phosphatase (PLAP) in cerebrospinal fluid (CSF) has been proposed as a tumor marker for intracranial germinomas. The purpose of the present study was to develop a sensitive assay for measuring CSF PLAP and to evaluate the clinical significance of PLAP in patients with germinomas.

METHODS

A chemiluminescent enzyme assay for PLAP was developed using an anti-human-PLAP monoclonal antibody. PLAP concentrations were determined in 37 controls, 36 germinomas, 3 nongerminomatous germ cell tumors, 21 gliomas and 12 other brain tumors.

RESULTS

The assay detection limit was 5 pg/ml. The median PLAP concentration in the control group was below the detection limit. Significantly higher PLAP levels were detected in all 36 germinoma patients, with values ranging from 16 to 3,700 pg/ml. The high PLAP concentrations of 17 germinoma patients decreased to below the detection limit after complete remission had been achieved with radiochemotherapy. The sensitivity and specificity of PLAP for germinomas were 94 and 97%, respectively, with a cutoff value of 30 pg/ml.

CONCLUSIONS

The results of this study suggest that the determination of CSF PLAP by the chemiluminescent method described here provides a clinically useful tumor marker for the diagnosis and monitoring of intracranial germinomas.

Shared molecular targets in pediatric gliomas and ependymomas

BACKGROUND

Recent advances in multidisciplinary treatment approaches have improved the overall prognosis of pediatric brain tumors, but some patients remain refractory to treatment and do poorly. Several molecularly targeted therapies are under development for the treatment of brain tumors, and high-grade gliomas in adults are a particular area of study.

PROCEDURE

To better understand if these new therapies can be used in pediatric populations, we examined the expression of the following seven marker genes involved in signaling pathways targeted by new therapies: β-catenin, suppressor of fused (SUFU), erythroblastic leukemia viral oncogene homolog (ERBB) 2, platelet-derived growth factor receptorα (PDGFRα), proliferating cell nuclear antigen (PCNA), secreted protein acid and rich in cysteine (SPARC), and granulocyte colony-stimulating factor receptor (G-CSFR). Samples from 27 patients with the primitive neuroectodermal tumor (PNET)/medulloblastomas (MBs) (n = 8), ependymomas (n = 5), or gliomas (n = 14) were assessed by quantitative real-time PCR. [Correction made here after initial online publication]. We assigned an EXP score to compare across samples and determined the levels of gene expression among tumor cell types.

RESULTS

Gene expression varied among the different tumors, but, within a tumor type, clear expression patterns were seen. The expression of SUFU, ERBB2, and PCNA in metastatic MBs were greater than that seen in non-metastatic MBs. Most glioma cases highly expressed PDGFRα and G-CSFR. Additionally, the expression patterns of gliomas and ependymomas were similar (r = 0.77, P = 0.04), but PNET/MBs substantially differed from gliomas (r = -0.37, P = 0.41) or ependymomas (r = 0.23, P = 0.62).

CONCLUSIONS

The development of new drugs targeting up-regulated pathways may be useful for the treatment of pediatric brain tumors. As new drugs are developed, gliomas and ependymomas may be treated with similar compounds.

A case of corticotroph carcinoma that caused multiple cranial nerve palsies, destructive petrosal bone invasion, and liver metastasis

A 52-year-old woman experienced sudden onset of double vision due to a right abducens nerve palsy and was diagnosed as having a pituitary macroadenoma that invaded into the right cavernous sinus. Otherwise, she was asymptomatic despite marked elevation of ACTH (293 pg/ml) and cortisol (24.6 μg/dl) levels. The patient underwent transsphenoidal surgery followed by γ-knife radiosurgery (GKR), which healed the diplopia and ameliorated the hypercortisolemia. The excised tumor was diffusely stained for ACTH with a high (15%) Ki-67 labeling index. Early tumor recurrence occurred twice thereafter, producing right lower cranial nerve palsies with petrosal bone destruction at 8 months and an ipsilateral oculomotor nerve palsy at 12 months after GKR; all palsies resolved completely with the second and third GKRs. Hypercortisolemia worsened rapidly soon after the third GKR, and the patient developed marked weight gain, hypokalemia, and hypertension. Multiple liver lesions were incidentally detected with computer tomography and identified as metastatic pituitary tumor on immunohistochemistry. An ACTH-producing adenoma should be followed carefully for early recurrence and/or metastatic spread when the tumor is an invasive macroadenoma with a high proliferation marker level. The unique aggressive behavior and high potential for malignant transformation of this case are discussed.

A case of TSH-producing adenoma treated with octreotide in combination with thiamazole for the control of TSH and thyroid hormones after trans-sphenoidal neurosurgery

While TSH-producing adenoma (TSHoma) is rare, the diagnosis is often delayed because the clinical features are heterogeneous. The patient was a 69-year-old woman who had been referred to the Yachiyo Medical Center in August 2008, because of dyspnea, loss of appetite, weight loss of 10 kg, and diarrhea that lasted 4 years. We diagnosed this patient with pituitary TSH-producing macroadenoma. Thyroid hormone concentration was increasing although the serum TSH level was within a normal range after trans-sphenoidal surgery. We considered that because of enlargement of the thyroid gland due to long-term stimulation by TSH, a low concentration of TSH could stimulate the thyroid gland to produce excess T3 or T4. The somatostatin analogue, octreotide was used to control the TSHoma and serum TSH concentration but not thyroid hormone. The octreotide in combination with thiamazole treatment for 14 months controlled thyroid hormone concentration and decreased the thyroid mass, and ultimately, the thiamazole could be stopped. To date, the use of combination therapy of octreotide with thiamazole in patients with remaining TSH-producing adenoma without Basedow's disease is rare, and we suggest that this treatment is one of the therapeutic means to treat recurrence of TSH-producing adenoma after surgery with progressive complications or large thyroid gland.

¹H-MRS of intracranial meningiomas: what it can add to known clinical and MRI predictors of the histopathological and biological characteristics of the tumor?

OBJECTIVE

The main goal of the present study was evaluation of proton magnetic resonance spectroscopy (¹H-MRS) in diagnosis of histopathologically aggressive intracranial meningiomas.

METHODS

Single-voxel ¹H-MRS of 100 intracranial meningiomas was performed before their surgical resection. Investigated metabolites included mobile lipids, lactate, alanine, N-acetylaspartate (NAA), and choline-containing compounds (Cho). According to criteria of World Health Organization (WHO) 82 meningiomas were assigned histopathological grade I, 11 grade II, and 7 grade III. The MIB-1 index varied from 0% to 27.3% (median, 1.6%). In 43 cases tight adhesion of the tumor to the pia mater or brain tissue was macroscopically identified at surgery. The consistency of 49 meningiomas was characterized as soft, 26 as hard, and 25 as mixed.

RESULTS

No one metabolic parameter had statistically significant association with histopathological grade and subtype, invasive growth, and consistency of meningioma. Univariate statistical analysis revealed greater ¹H-MRS-detected Cho content (P=0.0444) and lower normalized NAA/Cho ratio (P=0.0203) in tumors with MIB-1 index 5% and more. However, both parameters lost their statistical significance during evaluation in the multivariate model along with other clinical and radiological variables. It was revealed that non-benign histopathology of meningioma (WHO grade II/III) is mainly predicted by irregular shape (P=0.0076) and large size (P=0.0316), increased proliferative activity by irregular shape (P=0.0056), and macroscopically invasive growth by prominent peritumoral edema (P=0.0021).

CONCLUSION

While ¹H-MRS may be potentially used for the identification of meningiomas with high proliferative activity, it, seemingly, could not add substantial diagnostic information to other radiological predictors of malignancy in these tumors.

A case-case study of mobile phone use and acoustic neuroma risk in Japan

Results of case-control studies of mobile phone use and acoustic neuroma have been inconsistent. We conducted a case-case study of mobile phone use and acoustic neuroma using a self-administered postal questionnaire. A total of 1589 cases identified in 22 hospitals throughout Japan were invited to participate, and 787 cases (51%) actually participated. Associations between laterality of mobile phone use prior to the reference dates (1 and 5 years before diagnosis) and tumor location were analyzed. The overall risk ratio was 1.08 (95% confidence interval (CI), 0.93-1.28) for regular mobile phone use until 1 year before diagnosis and 1.14 (95% CI, 0.96-1.40) for regular mobile phone use until 5 years before diagnosis. A significantly increased risk was identified for mobile phone use for >20 min/day on average, with risk ratios of 2.74 at 1 year before diagnosis, and 3.08 at 5 years before diagnosis. Cases with ipsilateral combination of tumor location and more frequently used ear were found to have tumors with smaller diameters, suggesting an effect of detection bias. Furthermore, analysis of the distribution of left and right tumors suggested an effect of tumor-side-related recall bias for recall of mobile phone use at 5 years before diagnosis. The increased risk identified for mobile phone users with average call duration >20 min/day should be interpreted with caution, taking into account the possibilities of detection and recall biases. However, we could not conclude that the increased risk was entirely explicable by these biases, leaving open the possibility that mobile phone use increased the risk of acoustic neuroma.

Two cases of precocious puberty associated with hypothalamic hamartoma

Hypothalamic hamartoma (HH) is a congenital malformation diagnosed based on magnetic resonance imaging (MRI) and histological findings; it is often associated with central precocious puberty (CPP), gelastic seizures, abnormal behavior and mental retardation. In the present paper, we report our retrospective hypothesis that there is a relationship between symptoms and therapy, as well as the treatment for HH, and describe two cases of HH associated with CPP. Both cases had sessile masses located in the interpeduncular cistern, with extension to the hypothalamus on MRI (1.2 × 1.5 cm and 2.0 × 2.5 cm, respectively). The first case had intractable seizures, while the second had no seizures with paroxysmal discharge. In both patients, the hamartomas were partially removed, by γ-knife and surgical operation in the first case and surgically in the second, and a gonadotropin releasing hormone (GnRH) analogue was prescribed. One case showed improvement of both intelligence quotient (IQ) score and seizures, and the other showed improvements in IQ and abnormal behavior. It was difficult to determine any topology/symptom relationships. Surgery and GnRH analogue treatment can alleviate seizures, abnormal behavior and mental retardation associated with HH.

Optimal treatment strategy for craniopharyngiomas based on long-term functional outcomes of recent and past treatment modalities

Although many authors have described treatment strategies for craniopharyngiomas, the optimal treatment of craniopharyngiomas remains controversial. This study aimed to define an adequate surgical strategy for craniopharyngiomas by reviewing the long-term functional performance of patients treated by current and past treatment modalities. Fifty-five patients with longer than 5 years of follow-up were selected for the present long-term study. The duration of follow-up ranged from 5.5 to 33 years (median, 14.8 years). There were 28 adult patients (14 males; median age, 44.4 years) and 27 children younger than 16 years of age (15 males; median age, 8.1 years). The patients were divided into the following treatment groups: single surgery (group A; n=14 multiple surgeries (group B; n=8), surgery or surgeries followed by radiotherapy (group C; n=23), surgery or surgeries (partial removal) followed by radiotherapy + additional treatments (multiple surgeries and/or re-irradiation; group D; n=10). In addition to the routine assessments of neurological, endocrine, and visual outcomes, the level of daily functioning was analyzed using the Karnofsky Performance Scale (KPS). Statistical analysis of relationship between KPS score and treatment mode demonstrated that group D had a significantly lower KPS score (F=5.82, p=0.0017). Furthermore, mortality, cognitive function, and visual function were significantly better in groups A, B, and C than in group D. Multiple regression analysis demonstrated that cognitive dysfunction, visual disturbance, and treatment mode were independent covariates that significantly affected postoperative KPS score. Adequate primary treatment for craniopharyngiomas is important to avoid subsequent multiple treatments. Craniopharyngiomas should be removed surgically as far as possible but without further deteriorating cognitive and visual functions, either as total resection or subtotal resection with a small remnant that is controllable by radiation therapy.

Hemangiopericytoma in the lateral ventricle

A 31-year-old female presented with a particularly rare hemangiopericytoma (HPC) in the right lateral ventricle manifesting as a 6-month history of visual disturbance and headache. Left hemianopsia and choked disc were identified by an ophthalmologist who referred her to us. Magnetic resonance imaging demonstrated a 5-cm homogeneously enhanced mass in the trigone of the right lateral ventricle. The tumor was totally removed by two stage surgery. The histological findings were consistent with HPC. HPC is very important to differentiate from meningioma and solitary fibrous tumors because HPC is more aggressive. The histological and immunochemical findings are important for the differential diagnosis. The present case showed no local recurrence or metastasis without radiation therapy for 4 years, indicating that radiation therapy is not absolutely imperative for patients with intraventricular HPC showing low MIB-1 staining index after total removal.

Risk factors for regrowth of intracranial meningiomas after gamma knife radiosurgery: importance of the histopathological grade and MIB-1 index

INTRODUCTION

The influence of histopathological grade and MIB-1 index of intracranial meningioma on the results of its radiosurgical management is not clear. The objective of the present retrospective study was to make an evaluation of these factors along with an analysis of other variables associated with progression-free survival after gamma knife radiosurgery (GKR).

PATIENTS AND METHODS

Thirty-four intracranial meningiomas with known detailed histopathological diagnosis were analyzed. Tumors of WHO histopathological grades I, II, and III were diagnosed in 24, 3, and 7 cases, respectively. The median MIB-1 index was 1.3% (range: 0-31.9%). In 14 cases the MIB-1 index was 3.0% and more. In 26 cases the treatment was done at the time of tumor recurrence. Median volume of the neoplasm at the time of GKR was 4.1 mL (range: 0.4-43.1 mL). Median marginal dose was 12 Gy (range: 8-19 Gy). Median length of follow-up constituted 63 months (range: 19-132 months).

RESULTS

Actuarial progression-free survival at 1, 3, 5, and 10 years constituted 100, 94, 83, and 58%, respectively. Histopathological grade II or III (p<0.0001), MIB-1 index 3% and more (p=0.0004), and non-skull base location (p=0.0026) of the tumor showed negative associations with progression-free survival in multivariate analyses. Actuarial progression-free survival at 5 years after GKR for benign and non-benign meningiomas constituted 100 and 45%, respectively (p<0.0001).

CONCLUSION

Radiosurgery is a highly effective management option for benign intracranial meningiomas, but growth control of non-benign ones is significantly worse. It requires close neuroradiological follow-up and necessitates the search for modified treatment strategies.

[A case of gangliocytoma: a six-year follow-up of cyst formation]

We report a case of gangliocytoma at a cortical and subcortical area in the right parietal lobe. The patient had a generalized seizure at 11 years of age. The MRI shows an ill-demarcated high intensity area in T2 weighted images including an enhancing tumor of 10 mm in diameter. At first, the tumor was carefully followed up because of its small size and the surgical risk. Three years after the onset, a cyst formed at the area of the brain edema adjacent to the tumor. The cyst gradually grew to 21 mm in diameter, the edema had disappeared, and the size of the tumor became smaller (7 mm) within the next 3 years. A mural nodule, jelly-like tumor with calcification was totally removed and diagnosed as gangliocytoma. The cyst fluid was watery-clear, its wall did not contain any tumor. This is the first report of a six-year follow-up of cyst formation of gangliocytoma supporting the concept that edema is a precursor to central nervous system peritumoral cyst formation based on the similar observation of hemangioblastomas.

Clinical presentation of intracranial epidermoids: a surgical series of 20 initial and four recurred cases

Epidermoids are generally recognized as benign tumors; however, total resection is often difficult. The recurrence from the residual capsule, dissemination of the tumor, and aseptic meningitis are common problems. The aim of the present study was to analyze and report on the clinical characteristics of intracranial epidermoids, particularly complications and cases with a poor clinical outcome. 24 patients with intracranial epidermoids who were treated surgically at Tokyo Women's Medical University Hospital between 1997 and 2007 were examined. The location and size of the tumor, pre-and postoperative symptoms, adherence of the tumor to cranial nerves, and proliferative capacity were determined. The most frequent site of the tumor was the cerebello-pontine (C-P) angle (16/24); eight of these patients presented with hearing loss and six presented with trigeminal neuralgia. In many cases, hearing loss and diplopia persisted after surgery. All epidermoids located in the C-P angle were attached to and/or compressed the trigeminal nerves, therefore, the origin is suggested to be the dura mafer of petrous bone around the trigeminal nerve. Of all 24 patients, the tumor recurred in four (after 3, 5, 10 and 20 years). One patient had a poor prognosis, with dissemination and brain stem infarction. Epidermoids can recur from residual capsule adhering to the brain stem or cranial nerves up to 10-20 years after the initial surgery. Long-term follow-up imaging studies are required when complete resection of the tumor capsule is not possible. In rare cases, spontaneous cyst rupture, dissemination, and brain stem infarction result in a poor prognosis.

Power-frequency magnetic fields and childhood brain tumors: a case-control study in Japan

Background

The strength of the association between brain tumors in children and residential power-frequency magnetic fields (MF) has varied in previous studies, which may be due in part to possible misclassification of MF exposure. This study aimed to examine this association in Japan by improving measurement techniques, and by extending measurement to a whole week.

Methods

This population-based case-control study encompassed 54% of Japanese children under 15 years of age. After excluding ineligible targeted children, 55 newly diagnosed brain tumor cases and 99 sex-, age-, and residential area-matched controls were included in the analyses. The MF exposures of each set of matching cases and controls were measured in close temporal proximity to control for seasonal variation; the average difference was 12.4 days. The mean interval between diagnosis and MF measurements was 1.1 years. The weekly mean MF level was defined as the exposure. The association was evaluated using conditional logistic regression analysis that controlled for possible confounding factors.

Results

The odds ratios (95% CI) for exposure categories of 0.1 to 0.2, 0.2 to 0.4, and above 0.4 µT, against a reference category of <0.1 µT, were 0.74 (0.17–3.18), 1.58 (0.25–9.83), and 10.9 (1.05–113), respectively, after adjusting for maternal education. This dose-response pattern was stable when other variables were included in the model as possible confounding factors.

Conclusions

A positive association was found between high-level exposure—above 0.4 µT—and the risk of brain tumors. This association could not be explained solely by confounding factors or selection bias.

Histological findings at the boundary of craniopharyngiomas

Although a craniopharyngioma is grossly well circumscribed, microscopically the borders are frequently irregular and may be associated with gliosis in the adjacent brain tissue. In the current study, we investigated the histology of the interface between craniopharyngiomas and surrounding normal structures such as the hypothalamus and pituitary gland. Histologically, we classified the findings at the boundary of craniopharyngiomas into three types. In type 1, a relatively thick capsule-like tissue was identified at the boundary between the craniopharyngioma and surrounding normal structure composed of tumor cells and inflammatory changes. In type 2, a craniopharyngioma had a relatively clear cleavage between the surrounding gliosis. In type 3, the boundary had some interdigitation of the tumor in the surrounding gliotic layer adjacent to the craniopharyngioma. In types 1 and 3, surgeons may fail to accomplish complete resection of the tumor. These histological features may result in recurrence of craniopharyngioma even after gross total resection.

Role of proton magnetic resonance spectroscopy in preoperative evaluation of patients with mesial temporal lobe epilepsy

A retrospective study was conducted for evaluation of the role of single-voxel proton magnetic resonance spectroscopy (1H-MRS) in preoperative investigation of patients with mesial temporal lobe epilepsy (MTLE). Eighteen cases, including both non-lesional and lesional MTLE, were analyzed. Selective amygdalohippocampectomy was performed in 8 cases, selective amygdalohippocampectomy combined with lesionectomy in 6 cases, lesionectomy in 3 cases, and anterior temporal lobe resection in one case. The length of follow-up varied from 24 to 71 months (median, 35 months). Before surgery, (1)H-MRS disclosed decrease of N-acetylaspartate (NAA) content (P=0.01) and more frequent (P=0.07) presence of lactate (Lac) on the side of the epileptogenic zone. Decrease of NAA content below 0.75 and/or unilateral presence of Lac provided 86% (95% CI: 68%-100%) lateralization accuracy. Metabolic parameters did not differ in subgroups with hippocampal sclerosis and brain tumors. On the long-term follow-up 12 patients (67%) were free of disabling seizures. There was a trend (P=0.05) for worse seizure outcome in cases with significant bilateral metabolic alterations characterized by predominance of choline-containing compounds' peak on 1H-MR spectra on both sides. In conclusion, 1H-MRS-detected reduction of NAA content and unilateral presence of Lac in the mesial temporal lobe structures may serve as additional diagnostic clues for lateralization of the epileptogenic zone in MTLE. Metabolic imaging has limited usefulness for differentiation of the hippocampal sclerosis and low-grade intraaxial brain tumor. Presence of significant bilateral metabolic alterations in the mesial temporal lobe structures is associated with worse postoperative seizure control.

Dynamics of metabolic changes in intracranial metastases and distant normal-appearing brain tissue after stereotactic radiosurgery: a serial proton magnetic resonance spectroscopy study

The present study evaluated the dynamics of metabolic changes in intracranial metastases and distant normal-appearing brain after stereotactic radiosurgery (SRS). Forty neoplasms were evaluated with single-voxel proton magnetic resonance spectroscopy ((1)H-MRS) both before and after treatment. From one to six examinations (median, 3) were done in each individual case during follow-up. At the time of each investigation additional (1)H-MRS was obtained from the normal-appearing brain distant from the radiosurgical target. Investigated metabolites included N-acetylaspartate (NAA), choline-containing compounds (Cho), creatine (Cr), and mobile lipids (Lip). Within the first month after SRS responded tumors showed a statistically significant increase in NAA/Cho ratio, and decrease of Cho content and Lip-to-normal brain Cr (nCr) ratio. By contrast, statistically significant metabolic alterations were not detected in stabilized tumors. Statistically significant volumetric and metabolic changes were not marked between three and 12 months after treatment in non-progressing lesions. Alternatively, decrease of NAA/Cho ratio, NAA content and Cr content, and increase in Lip/nCr ratio and Cho content were evident in progressive neoplasms, and subtle metabolic alterations could be revealed even before the increase in the lesion volume. Metabolic characteristics of normal-appearing brain distant from the radiosurgical target did not show statistically significant changes within the first year after treatment. In conclusion, additional use of serial (1)H-MRS during follow-up after SRS for intracranial metastases permits detailed evaluation of the metabolic tumor response and may be potentially helpful for early prediction of recurrence.

Coincidence of central neurocytoma and multiple glioblastomas: a rare case report

Coincidence of parenchymal primary brain tumors of different histogenesis is extremely rare. To the best of our knowledge, the present case of simultaneous appearance of a central neurocytoma and multiple glioblastomas is the first to be reported. Multiple intraaxial brain neoplasms were disclosed in a 39-year-old man and were surgically resected. Histological diagnosis of the tumor located in the right lateral ventricle was central neurocytoma whereas two tumors of the left temporal lobe were glioblastomas. The latter were located in close proximity to the subarachnoid space, had atypical radiological appearance, and were slightly positive for synaptophysin and neurofilament protein. It can be speculated that both malignant neoplasms were, in fact, dedifferentiated central neurocytoma, which developed from distant tumor deposits. This case seems to be in agreement with the hypothesis that central neurocytoma arises from the progenitor cells with potential for both neuronal and glial differentiation. Better understanding of histogenesis of this tumor is definitely needed.

Prospective study of high-dose cabergoline treatment of prolactinomas in 150 patients

CONTEXT

Cabergoline fails to normalize hyperprolactinemia in a considerable proportion of prolactinomas, especially macroadenomas.

OBJECTIVE

We examined the effect of individualized high-dose cabergoline treatment on hyperprolactinemia in prolactinomas.

PATIENTS

The study included 122 women and 28 men (93 microadenomas and 57 macroadenomas). Forty-seven had undergone transsphenoidal surgery. According to the preceding medical treatment, the participants were separated into untreated (group U; n = 60), intolerant (group I; n = 64), and resistant (group R; n = 26) groups.

INTERVENTIONS

We promptly increased cabergoline dose on the basis of individual prolactin levels. Length of treatment was 1 yr.

RESULTS

Cabergoline normalized hyperprolactinemia in all patients except one. The proportion of prolactin normalization in both groups U and I was 83% at 3 months and 95% at 6 months. By contrast, that in group R was 35% at 3 months and 58% at 6 months. Mean cabergoline dose in milligrams per week at the time of prolactin normalization was 2.0 +/- 0.3 in group U, 0.9 +/- 0.1 in group I, and 5.2 +/- 0.6 in group R. Prolactin normalization rate at the 3 mg/wk dose was 84% overall but only 35% in group R. Serum progesterone or testosterone levels, diminished in 122 women or 16 men, respectively, were recovered in all except one resistant and four postmenopausal or panhypopituitary patients.

CONCLUSION

Individualized high-dose cabergoline treatment can normalize hyperprolactinemia and hypogonadism in nearly all prolactinomas irrespective of tumor size or preceding treatments. Hyperprolactinemia could be controlled in poor responders within 1 yr with doses higher than 3 mg/wk.

Oral administration of choline does not affect metabolic characteristics of gliomas and normal-appearing white matter, as detected with single-voxel (1)H-MRS at 1.5 T

INTRODUCTION

The present study was done for evaluation of the possible influence of the oral administration of choline on metabolic characteristics of gliomas detected with proton magnetic resonance spectroscopy ((1)H-MRS).

MATERIALS AND METHODS

Thirty patients (22 men and eight women; mean age 38 +/- 15 years) with suspicious intracranial gliomas underwent single-voxel long-echo (TR 2,000 ms, TE 136 ms, 128-256 acquisitions) (1)H-MRS of the tumor, peritumoral brain tissue, and distant normal-appearing white matter before and several hours (median, 3 h; range, 1.2-3.7 h) after ingestion of choline with prescribed dose of 50 mg/kg (median actual dose, 52 mg/kg; range, 48-78 mg/kg). Investigations were done using 1.5 T clinical magnetic resonance imager. The volume of the rectangular (1)H-MRS voxel was either 3.4 or 8 cm(3). At the time of both spectroscopic examinations, similar voxels' positioning and size and technical parameters of (1)H-MRS were used. Surgery was done in 27 patients within 1 to 68 days thereafter. In all cases, more than 80% resection of the neoplasm was attained.

RESULTS

There were 12 low-grade gliomas and 15 high-grade gliomas. MIB-1 index varied from 0% to 51.7% (median, 13.8%). Statistical analysis did not disclose significant differences of any investigated metabolic parameter of the tumor, peritumoral brain tissue and distant normal-appearing white matter between two spectroscopic examinations.

CONCLUSION

Single-voxel (1)H-MRS at 1.5 T could not detect significant changes of the metabolic characteristics of gliomas, peritumoral brain tissue, and distant normal-appearing white matter after oral administration of choline.

Possible role of single-voxel (1)H-MRS in differential diagnosis of suprasellar tumors

The objective of the present study was investigation of the possible role of proton magnetic resonance spectroscopy ((1)H-MRS) for differential diagnosis of suprasellar tumors. Forty patients (23 men and 17 women; median age, 45 years) with suprasellar, hypothalamic, and third ventricle neoplasms underwent long-echo (TR: 2000 ms, TE: 136 ms, 128-256 acquisitions) single-voxel (1)H-MRS before surgical treatment. The volume of the voxel was either 3.4 cc or 8 cc. Spectroscopic data were analyzed by calculation of the various metabolite ratios as well as by determination of the type of the pathological (1)H-MR spectra. There were 19 pituitary adenomas, 7 gliomas, 5 craniopharyngiomas, 3 chordomas, meningioma, hemangiopericytoma, malignant lymphoma, germinoma, Rathke cleft cyst, and hypothalamic hamartoma (one of each). Six tumors were recurrent after initial surgical resection with or without irradiation. Comparison of the individual metabolite ratios revealed only few subtle differences among neoplasms. In the same time, pattern analysis with determination of the type of the pathological (1)H-MR spectra disclosed certain specific characteristics, which seemingly can be used for tumor typing. Meanwhile, metabolic imaging was less effective for characterization of recurrent neoplasms. In conclusion, in cases of initially diagnosed suprasellar tumors with involvement of the hypothalamus and extension into the third ventricle pattern analysis of the single-voxel (1)H-MRS can provide valuable information, which, in addition to structural MRI, can be effectively used for diagnostic purposes.

Intracranial epidermoid tumor after subcutaneous lipoma excision

A 66-year-old man presented with complaints of numbness for the past 5 years and progressive motor weakness of the right leg for the previous 2 months. Magnetic resonance imaging revealed large intra- and extracranial tumors in the frontoparietal region. Physical examination suggested the extracranial lesion was a subcutaneous lipoma, which had been partially resected 60 years before, connected to the intracranial lesion via a defect of the skull. Gross total removal of the tumors was performed. Histological examination showed the intracranial lesion was epidermoid tumor, and connected to the extracranial lipoma by a lipoma bridge. The symptoms improved remarkably following surgery. This case of intracranial epidermoid tumor associated with intra-extracranial lipoma indicates that implantation of skin tissue in childhood carries the risk of epidermoid tumor even after several decades. Neuroimaging screening is recommended to detect the development of any intracranial components.

Differentiation of High-Grade and Low-Grade Gliomas Using Pattern Analysis of Long-Echo Single-Voxel Proton Magnetic Resonance Spectroscopy ((1)H-MRS)

The usefulness of proton magnetic resonance spectroscopy ((1)H-MRS) for glioma grading is not clear, particularly due to the absence of standard criteria for data analysis. Previously we had developed an original classification of the pathological (1)H-MRS spectra based on the identification of the predominant metabolite peak, N-acetylaspartate (NAA) for Type I, choline-containing compounds (Cho) for Type II, and mobile lipids (Lip) for Type III, and presence or absence of other metabolite peaks: lactate (Lac), Lip, or Cho. The present study evaluated the effectiveness of this classification in grading of previously non-treated gliomas. A total of 38 low-grade and 33 high-grade neoplasms were investigated. Four tumors had (1)H-MRS spectra Type I, and all of those were low-grade. Three tumors had (1)H-MRS spectra Type III, and all those were glioblastomas. Fifteen tumors with (1)H-MRS spectra Type II had a Lip/NAA ratio more than 1 (Type II C with moderate elevation of lipids), and 12 of those neoplasms were high-grade. The differences in distribution of high-grade and low-grade gliomas among another 49 gliomas with (1)H-MRS spectra Type II did not depend on the presence of Lac and/or Lip peaks, and in this subgroup NAA/Cho ratio was also evaluated. Inclusion of both characteristics (type of the (1)H-MRS spectrum and NAA/Cho ratio with defined cut-off level of 0.6) into the diagnostic algorithm yielded 72% diagnostic accuracy (95% confidence interval: 62%-82%) in discriminating high-grade and low-grade neoplasms. In conclusion, pattern analysis of the pathological (1)H-MRS spectra using the proposed classification along with evaluation of NAA/Cho ratio might be helpful for non-invasive glioma grading.

Usefulness of intraoperative magnetic resonance imaging for glioma surgery

BACKGROUND

Radical resection of gliomas can increase patient's survival. There is known concern, however, that aggressive tumour removal can result in neurological morbidity. The objective of the present study was to evaluate the usefulness of low magnetic field strength (0.3 Tesla) open intraoperative magnetic resonance imaging (iMRI) for complete resection of glioma with emphasis on functional outcome.

METHODS

From 2000 to 2004, 96 patients with intracranial gliomas underwent tumour resection with the use of iMRI in Tokyo Women's Medical University. There were 50 men and 46 women; mean age was 39 years. Tumour volume varied from 1.2 ml to 198 ml (median: 36.5 mL). Resection rate and postoperative neurological status were compared between control group (46 cases, operated on during the initial period after installation of iMRI), and study group (50 most recent cases, in whom surgery was done using established treatment algorithm and improved image quality).

FINDINGS

Overall, mean resection rate was 93%, and medial residual tumour volume was 0.17 ml. Total tumour removal was achieved in 44 cases (46%). Compared to control group, resection rate in the study group was significantly higher (91%, vs. 95%; P < 0.05), whereas residual tumour volume was significantly smaller (1.7 mL vs. 0.025 mL; P < 0.001). Nine patients in the control group (20%) and 24 in the study group (48%) experienced temporary postoperative neurological deterioration (P < 0.01), however, the rate of permanent morbidity evaluated 3 months after surgery did not differ significantly between the groups investigated (13% vs. 14%).

CONCLUSIONS

Use of iMRI during surgery for intracranial gliomas permits to attain aggressive tumour resection with good functional outcome. Nevertheless, surgical experience with the iMRI system, establishment of treatment algorithm, and improvement of image quality are of paramount importance for optimal results.

Management and prognosis of cysts developed on long-term follow-up after Gamma Knife radiosurgery for intracranial arteriovenous malformations

BACKGROUND

Delayed cyst formation is a well-recognized complication after radiosurgery for intracranial AVM. The objective of the present study was the evaluation of the different management options for these lesions and the corresponding prognosis of patients.

METHODS

Between 2000 and 2005, 12 patients with intracranial AVM initially treated by GKR were reevaluated at Tokyo Women's Medical University because of delayed cyst formation in the vicinity of the target area. There were 7 men and 5 women. The mean age of the patients was 31.8 years at the time of GKR and 41.1 years at the time of complication. The average period between treatment and diagnosis of the complication constituted 6.7 years. All AVMs had lobar location and showed complete angiographic obliteration after GKR.

RESULTS

The most common neurological signs and symptoms at the time of cyst presentation were headache (10 cases) and seizures (4 cases). Two patients were asymptomatic. Three patients underwent surgery soon after the diagnosis of the cyst, whereas initial observation was done in another 9. Among the latter, 5 patients had to be treated surgically thereafter because of persistent or aggravated neurological symptoms associated with radiological cyst expansion. Four other patients, including both asymptomatic ones, are in stable condition without surgery. Follow-up after treatment of the cyst varied from 7 to 60 months (average, 34.3 months). All patients are in good condition.

CONCLUSIONS

Although delayed formation of cysts after GKR for intracranial AVM should be considered as a complication of the radiosurgical treatment, it has a relatively good prognosis. Observation can be recommended as initial option for compensated and asymptomatic patients.

Increased expression of ephrin A1 in brain arteriovenous malformation: DNA microarray analysis

A number of previous studies have revealed the abnormal expression of various angiogenesis-related genes or products in brain arteriovenous malformation (AVM). To understand the molecular process of this disease, we analyzed gene expression profiles in brain AVM. Using a DNA microarray consisting of 17,086 genes, we identified differentially expressed genes in 5 brain AVMs from their draining veins, vessels retaining basic venous architecture. Not many genes were differentially expressed between the AVM nidus and the draining vein. When we applied an absolute cut-off value for normalized log2 (cy5/cy3 ratio) of 0.4, 19 genes were selected. Genes such as SOX8, TRIM2, FENA1 (ephrin A1), and AQP4 were upregulated, and genes such as I_1000105, KRT18, IGFBP7, EMILIN-2, and KRT14 were downregulated. Genes relating to angiogenesis, such as vascular endothelial growth factor and angiopoietin and other members of the ephrin family, were not differentiated. Among differentially expressed genes detected in this analysis, we focused on ephrin A1, a gene related to embryogenesis and angiogenesis. The expression of ephrin A1 was two and three to nine times higher than that of the draining vein and normal brain, respectively, using real-time reverse transcription-polymerase chain reaction. For the first time, here we report the increased expression of ephrin A1 in brain AVM, which may play an important role in the pathogenesis of AVM.

Expression of type 5 somatostatin receptor in TSH-secreting pituitary adenomas: a possible marker for predicting long-term response to octreotide therapy

In TSH-secreting pituitary adenomas (TSHoma), octreotide (OCT) therapy reduces tumor size and TSH secretion in some cases but not in others. As OCT acts through various types of somatostatin receptors (SSTRs), the different responses of TSHoma to OCT might be explained by the differences of SSTR expression. We therefore studied the expression of subtype-specific SSTR mRNA transcripts in tumor tissues by RT-PCR. Type 2 (SSTR2) mRNA transcripts were detected in all 8 tumors but those of SSTR3 and SSTR5 were demonstrated only in 5 of them. Serum TSH levels were decreased by OCT administration test in all patients but OCT therapy was effective in two patients out of three. SSTR5 mRNA was detected in two tumors from the responder, but not in one tumor that was resistant to OCT. These observations suggest that the temporal decrease of TSH by OCT may be mediated by SSTR2, and that the long term response to OCT therapy may be related with the expression of SSTR5. Therefore, the expression of SSTR5 in TSHoma may be a useful marker for predicting the outcome of the therapy, but further studies with larger numbers of patients are necessary.

Hypothalamic hamartoma associated with anterior paraclinoid aneurysm of the internal carotid artery

A 15-year-old boy presented with a history of medically refractory gelastic seizures and cognitive impairments. Neuroimaging demonstrated a sessile type hypothalamic hamartoma, which was treated by gamma knife surgery. However, the gelastic seizures only partially decreased and the frequency of seizures remained unchanged. One year later, angiography before surgery detected anterior paraclinoid aneurysm of the left internal carotid artery. Blood pressure and endocrinological examinations showed no abnormality. Direct surgery was performed to treat the aneurysm and hamartoma. No sclerotic changes were noted in the arterial wall. The aneurysm was treated with clipping, and the hamartoma was partially removed. Postoperative course was uneventful and the gelastic seizures disappeared. No evidence for a causal relationship between the hamartoma and aneurysm was found.

Intrasellar remote metastasis from adenoid cystic carcinoma of parotid gland: case report

Adenoid cystic carcinoma is a tumor of exocrine glands originating primarily from the minor and major salivary glands, lacrimal gland, bronchus, breast, and intestinal and genital tracts. Intracranial remote metastasis from adenoid cystic carcinoma in salivary gland is quite rare. The authors encountered a case of intrasellar remote metastasis from an adenoid cystic carcinoma of parotid gland origin, presenting with hyponatremia secondary to the syndrome of inappropriate secretion of antidiuretic hormone (SIADH). To our knowledge, this is the first reported case of metastasis from an adenoid cystic carcinoma to intrasellar area. A 78-year-old woman had an adenoid cystic carcinoma in the left parotid gland, which was resected surgically followed by local radiation therapy of 60 Gy. After 4 years, the patient presented with general malaise, followed by disturbed consciousness caused by hyponatremia. The clinical data showed severe hyponatremia induced by SIADH. An intrasellar heterogenous mass lesion compressing the optic chiasm was resected subtotally via an endonasal transsphenoidal approach. Histopathological examination of the tumor specimens revealed adenoid cystic carcinoma, which had identical histological findings as those of the painful superficial cervical lymph nodes resected in the same operation. Tumors such as the present case are easily confused with pituitary adenoma or craniopharyngioma. Although rare, metastasis from tumors including those of salivary gland origin should be considered in the differential diagnosis of unusual pituitary tumors.

Neurofiberscopic biopsy of tumors of the pineal region and posterior third ventricle: indications, technique, complications, and results

OBJECTIVE

Evaluation of results of the neurofiberscopic biopsy of tumors of the pineal region and posterior third ventricle.

METHODS

From 2001 to 2004, 23 patients (mean age, 30.6 yr) with tumors located in the pineal region or posterior third ventricle underwent neurofiberscopic biopsy with simultaneous third ventriculostomy. The procedure was indicated for verification of the histological diagnosis of the neoplasm, which was planned to be treated by radiotherapy and/or chemotherapy without open surgery (eight patients), establishment of the pathological diagnosis for further choice of the most appropriate treatment strategy (11 patients), differentiation of the recurrent neoplasm and radiation necrosis (two patients), and decompression of the large tumor-associated cyst (two patients). In six previously shunted patients, substitution of the ventriculoperitoneal shunt on the third ventricle stoma was performed.

RESULTS

There was no postoperative mortality or permanent morbidity. In all cases, the obtained tissue sample was sufficient for pathological diagnosis. Transient postoperative complications included fever (15 patients), nausea and vomiting (three patients), and diplopia (one patient). On the long-term follow-up, delayed third ventricular stoma failure caused by tumor regrowth and scar formation was found in one patient, and dissemination of the malignant glioma through the subarachnoid space was found in another patient.

CONCLUSION

Neurofiberscopic biopsy represents a useful method for sampling of tumors of the pineal region and posterior third ventricle, which can be effectively used in both previously shunted and shunt-free patients.

Clinical and radiological features related to the growth potential of meningioma

Clinical and radiological features that help predict the growth potential of meningioma would be beneficial. The purpose of this study is to clarify the characteristics related to proliferating potential using the MIB-1 staining index. We analyzed the relationship of MIB-1 staining indices to characteristics of 342 consecutive patients with meningioma surgically removed between 1995 and 2004 by logistic regression analysis. One hundred and forty-nine of the patients with meningioma were >or=60 in age; 89 male; 48 recurrent; 203 symptomatic; 157 at the skull base; 124 over 20 cm(3); 24 multiple; 136 with edema; 117 with calcification. The MIB-1 staining index in 56 of 296 grade I meningiomas in WHO classification was >or= 3.0; in 27 of 28 grade II; and in 17 of 18 grade III, respectively. Logistic regression analysis demonstrated that male (odds ratio [OR], 2.374, p=0.003), recurrence (OR, 7.574, p=0.0001), skull base (OR, 0.540, p=0.035), calcification (OR, 0.498, p=0.019) were independent risk factors for a high MIB-1 staining index (>or=3.0); age, symptomatic, volume, multiple, edema were not. Male, recurrence, non-skull base, absence of calcification are independent risk factors for a high proliferative potential. These should be taken into consideration when managing meningiomas.