Ki-67 labelling index in human brain tumours

The proliferative potential in 157 brain tumours was investigated using Ki-67 labelling index (Ki-67LI). There were 46 patients with low grade gliomas (Al & All), 82 with high grade gliomas (AIII & AIV) and 29 with metastatic tumours. Tumour fragments used for assessment of Ki-67LI were fixed in formalin. Ki-67 antigen was visualised on paraffin sections using DAKO Rabbit Anti-Human Ki-67 antigen. The Ki-67LI was calculated as the percentage of Ki-67 labelled cells. The tumours showed variability in the Ki-67LI values. Significantly higher mean Ki-67LI was found for highly malignant (AIII & AIV) than for low grade gliomas (Al & All). For metastatic tumours, the mean values of Ki-67LI were significantly higher than for gliomas. Moreover, Ki-67LI of metastatic tumours were significantly higher than for high grade gliomas.     

Expression of the small heat shock protein (hsp) 27 in human astrocytomas correlates with histologic grades and tumor growth fractions

Summary 1. Cellular expression and distribution of the stress response small heat shock protein 27 (hsp27) in 39 high-grade astrocytomas (27 glioblastoma multiformes, 12 anaplastic astrocytomas) and in 27 low-grade astrocytomas (grade I–II) were analyzed immunohistochemically.2. The correlation between hsp27 expression and tumor growth fractions of the astrocytomas was examined following Ki-67 immunostaining.3. The hsp27 staining was cell cytoplasmic. The hsp27 immunopositive rate was significantly higher in high-grade astrocytomas; the rates were 74% for glioblastomas, 58% for anaplastic astrocytomas, and 37% for low-grade astrocytomas. The small and large tumor cells, especially in glioblastomas, multinucleated tumor giant cells, tumor cells in the pseudopalisading and necrotic areas, cells of the microvascular endothelial proliferations, and tumor vascular smooth muscles were usually hsp27 positive. The mean percentage of hsp27-positive cells was significantly higher in the glioblastomas alone and in the combined high-grade astrocytomas, compared to the low-grade, and in recurrent rather than in primary high-grade astrocytomas.4. The high-grade astrocytomas had a highly statistical significant Ki-67 labeling index. The Ki-67 labeling indices were significantly higher in the hsp27-positive than the hsp27-negative astrocytomas, irrespective of the histological grade. In the high-grade astrocytomas with a Ki-67 labeling index of five and above, 81% of those tumors were hsp27 positive.5. Thus, a large number of human astrocytomas express hsp27, and hsp27 expression correlates with histological grades of astrocytoma and with tumor growth fractions. This being the case, hsp27 is likely to have a role in the growth of human astrocytomas.     

Correlation between preoperative magnetic resonance spectroscopic data on high grade gliomas and morphology of Ki-67-positive tumor cell nuclei

OBJECTIVE: To investigate possible statistical correlations between metabolic data from preoperative proton magnetic resonance spectroscopy (1HMRS) and morphology of proliferating tumor cell nuclei in anaplastic gliomas and glioblastomas. STUDY DESIGN: Ki-67-positive tumor cell nuclei in paraffin sections of surgical specimens from 36 patients (7 anaplastic gliomas, World Health Organization grade 3; 29 glioblastomas, World Health Organization grade 4) were investigated by means of a digital image analysis system. Stringent inclusion criteria were formulated for all cases with respect to histologic quality and spectroscopic examination. As morphometric variables, nuclear area, shape variables (roundness factor, size-invariate Fourier amplitudes) and density of Ki-67-positive tumor cell nuclei per reference area were determined. RESULTS: Correlation analysis according to Spearman revealed a significant positive correlation between the total creatine (TCR) peak and nuclear area (P = .005). This correlation was also found within the glioblastoma group (P = .019). There was also a significant negative correlation of nuclear area with the ratio between choline and TCR in all cases (P = .014) and within the glioblastoma group (P = .046). No significant correlation of spectroscopic data was found with nuclear shape or density of Ki-67-positive tumor cell nuclei. CONCLUSION: The results demonstrate a correlation between spectroscopic data and morphology of proliferating tumor cell nuclei (nuclear size) in high grade gliomas. This study is part of a detailed investigation of the interrelationship between preoperative 1HMRS and quantitative histomorphology of gliomas.     

Identification of COL6A1 as a differentially expressed gene in human astrocytomas

Diffuse infiltrating gliomas are the most common tumors of the central nervous system. Gliomas are classified by the WHO according to their histopathological and clinical characteristics into four classes: grade I (pilocytic astrocytoma), grade II (diffuse astrocytoma), grade III (anaplastic astrocytoma), and grade IV (glioblastoma multiforme). Several genes have already been correlated with astrocytomas, but many others are yet to be uncovered. By analyzing the public SAGE data from 21 patients, comprising low malignant grade astrocytomas and glioblastomas, we found COL6A1 to be differentially expressed, confirming this finding by real time RT-PCR in 66 surgical samples. To the best of our knowledge, COL6A1 has never been described in gliomas. The expression of this gene has significantly different means when normal glia is compared with low-grade astrocytomas (grades I and II) and high-grade astrocytomas (grades III and IV), with a tendency to be greater in higher grade samples, thus rendering it a powerful tumor marker.     

Cyclooxygenase-2 expression in astrocytomas. Relationship with microvascular parameters, angiogenic factors expression and survival

OBJECTIVE: Cyclooxygenase-2 (COX-2) is the enzyme isoform involved in the synthesis of prostaglandins (PGs) and thromboxane from arachidonic acid. The role of the up-regulation of COX-2 in the formation and progression of gliomas has been dealt with in earlier reports, which describe increased levels of PGs within gliomas. In the present study, we examined the expression of COX-2 in diffuse gliomas of astrocytic origin in relation to microvascular parameters, angiogenic factors and survival. MATERIALS AND METHODS: A total of 83 cases of diffuse astrocytomas (grade II-IV) were analyzed by immunohistochemistry for the presence of COX-2. RESULTS: COX-2 expression was detected in 79 cases (95%) with an increased expression in grade IV as compared to grades II/III (p=0.024). A positive correlation occurred between COX-2 and angiogenic factors such as vascular endothelial growth factor (VEGF) (p<0.0001) and hypoxia inducible factor (HIF)-1alpha (p=0.005), as well as the tumours' proliferative activity (expressed as the percentage of Ki-67 positive cells) (p=0.032), and total vascular area (TVA) (p=0.040). In univariate analysis, COX-2 was associated with shortened survival (p = 0.050). Multivariate survival analysis showed that the interaction model of COX-2 with grade along with age were the only significant prognostic indicators. CONCLUSION: These results implicate COX-2 in the angiogenesis and biological aggressiveness of diffuse astrocytomas, and suggest that it would be worthwhile to examine how the inhibition of COX-2 expression may influence astrocytoma patients' survival.     

Topometric analysis of diffuse astrocytomas

OBJECTIVE: To investigate differences between astrocytomas of WHO grade 2 and anaplastic astrocytomas of WHO grade 3 in terms of topometric variables characterizing individual tumor cell nuclei. STUDY DESIGN: Paraffin sections from surgical specimens from 25 astrocytomas (grade 2, n = 11; grade 3, n = 14) were analyzed by means of an image analysis system. At least 300 tumor cell nuclei were measured in the region with the highest Ki-67 proliferation index. Three different kinds of topometric variables were determined for each tumor cell nucleus: (1) several distances; (2) the variable Angle 2/1, the angle between the straight lines representing the distance to the nearest and second-nearest nucleus; and (3) the number of neighbors according to our mathematical definition. RESULTS: Most topometric variables showed distinct differences between the 2 tumor grades (multivariate analysis of variance), with 88% cases correctly reclassified by means of cross-validated discriminant analysis. The variables with the highest discriminatory power were the SD of Angle 2/1 and the ratio between the distance to the second-nearest and nearest tumor cell nucleus, with lower values for these variables in anaplastic astrocytomas. Even variables concerning neighborhood relationships showed significant differences. CONCLUSION: The results of this pilot study show that this first set of topometric variables is sufficient to detect differences between topologic characteristics of tumor cell nuclei in astrocytomas grade 2 and grade 3. Topometry seems to be an important tool for grading astrocytomas.     

Relationship between EGFR overexpression and gene amplification status in central nervous system gliomas

OBJECTIVE: To correlate epidermal growth factor receptor (EGFR) protein overexpression, as assessed by immunohistochemistry, with EGFR gene amplification determined by fluorescence in situ hybridization in a series of gliomas. STUDY DESIGN: Forty-seven central nervous system gliomas, including 34 cases of glioblastoma multiforme, 3 oligodendrogliomas, 4 juvenile pilocytic astrocytomas and 5 low grade astrocytomas, were obtained from the files of the University of Utah Pathology Department. In each case a representative paraffin block was selected, and EGFR protein expression was quantified using immunohistochemistry. EGFR gene amplification status was determined by fluorescence in situ hybridization. RESULTS: EGFR protein overexpression was detected in 9 cases of glioblastoma multiforme. EGFR gene amplification was present in 7 of these cases. Both nonamplified glioblastomas demonstrated only 2+ overexpression of EGFR protein. None of the low grade, pilocytic or anaplastic astrocytomas demonstrated either EGFR protein overexpression or gene amplification. CONCLUSION: EGFR protein overexpression is closely associated with gene amplification. Seventy-eight percent of cases showing protein overexpression demonstrated gene amplification. All cases of central nervous system neoplasms showing protein overexpression but lacking gene amplification were associated with only 2+ protein overexpression. All central nervous system neoplasms demonstrating gene amplification and/or overexpression were high grade neoplasms.     

Lectins as differentiation markers of human gliomas.

The lectins Concanavalin A (Con A), Ricinus communis agglutinin (RCA-I), Peanut agglutinin (PNA) and Wheat germ agglutinin (WGA) as well as the immunomarkers for glial fibrillary acidic protein (GFAP) and myelin basic protein (MBP) were used in a series of 21 glial tumors (4 pylocytic astrocytomas, 5 grade II astrocytomas, 3 anaplastic astrocytomas, 4 glioblastomas and 5 oligodendrogliomas). ConA binds to all tumoral astrocytes in low grade astrocytomas, as well as to well differentiated tumoral astrocytes in anaplastic astrocytomas and glioblastomas. RCA-I has a similar behaviour. PNA, and to a lesser degree WGA, binds selectively to the oligodendroglial plasma membrane in well differentiated oligodendrogliomas. The results suggest that these lectins are markers of differentiation in gliomas rather than of malignancy.     

Immunocytochemical evaluation of proliferative activity in human brain tumours

The immunocytochemical expression of the antigen reacting with the monoclonal antibody Ki-67 (Ki-67 positivity) was investigated in 50 imprint preparations from human brain tumours. Data were related to tumour proliferative activity, as determined from in vivo bromodeoxyuridine (BrdU) incorporation (BrdU-labelling index, BrdU-LI) and histology. The percentage of Ki-67-positive cells was greater than the corresponding BrdU-LI value in all tumours, and the differences in Ki-67 positivity among tumour subtypes paralleled the BrdU-LI differences. Both the BrdU-LI and the percentage of Ki-67 positive cells were significantly greater (P less than 0.005) in the group of clinically aggressive adult tumours, histologically identified as anaplastic astrocytomas and glioblastomas, than in the less aggressive ones (oligodendroglioma, meningiomas, schwannomas, pituitary adenomas, dermoid cyst) and in the cerebral metastatic localizations. These data suggest that Ki-67 positivity, which is easily evaluated with immunocytochemistry, is related to the proliferative activity of brain tumours and that this parameter is endowed with clinical significance.     

p53 protein expression and proliferative activity in imprints of superficial transitional cell carcinoma of the bladder

OBJECTIVE: To investigate p53 protein expression and proliferative activity in imprints of tumor biopsies from superficial transitional cell carcinoma of the bladder in relation to the histologic grade of malignancy and recurrence status. STUDY DESIGN: The study group consisted of 70 cases of superficial transitional cell carcinoma of the bladder. In order to investigate p53 protein expression and Ki-67 expression, an immunocytochemical avidin-extravidin complex technique was performed using monoclonal antibodies p53 D0-7 and proliferating cells correspondingly. RESULTS: Thirty-seven percent of superficial transitional cell carcinoma cases showed positive expression of p53 protein. No correlation was found between p53 protein expression and grade of malignancy (P = .45). p53 Protein expression was statistically correlated with a high Ki-67 labeling index (LI) (P < .001) and recurrence status (P < .001). Forty-seven percent of cases showed a Ki-67 LI > 25%. No correlation was found between a high Ki-67 LI and grade of malignancy (P = .703). A significant difference in high Ki-67 LI between recurrent and nonrecurrent tumors of the same grade (P < .001) and between recurrent and nonrecurrent tumors was found independently of grade (P < .001). CONCLUSION: These results on cytologic material could provide useful information on the biologic behavior of superficial transitional cell carcinoma of the bladder at the time of diagnosis.     

Grading follicular lymphoma on fine needle aspiration specimens. Comparison with proliferative index by DNA image analysis and Ki-67 labeling index

OBJECTIVE: To determine whether follicular lymphoma (FL) can be graded on fine needle aspiration (FNA) biopsies by determining the percentage of centroblasts in the neoplastic follicles on the smears. STUDY DESIGN: Eighty-nine cases of histologically confirmed cases of FL, including 31 grade 1, 46 grade 2 and 12 grade 3, were evaluated. Proliferative index (PI) by DNA image analysis (DIA) and Ki-67 labeling index (LI) were obtained on all cases. A minimum of 200 cells were counted per case (range, 200-800 cells) at 40x magnification, and the number of large cells (centroblasts) was expressed as a percentage of the total number of cells counted within the follicles. RESULTS: The percentage of centroblasts in the follicular aggregates was 9.7 +/- 2.9% in grade 1 FLs, 24.7 +/- 5.6% in grade 2 and 48.4 +/- 7.5% in grade 3. These differences were significant (P < .05). DNA image analysis of PI and Ki-67 LI differed significantly between grade 1 FLs and grade 2 and 3 FLs (P < .05), but there were no significant differences between grade 2 and 3 FLs. CONCLUSION: Determining the percentage of centroblasts in the follicular aggregates on FNA specimens is a good method of grading FLs. Using the percentage of centroblasts per follicular structure, FL grades 1, 2 and 3 were adequately distinguished. PI by DIA and Ki-67 LI clearly distinguished FL grade 1 from FL grades 2 and 3; however, it did not clearly distinguish between grades 2 and 3.     

H3 mRNA level as a new proliferative marker in astrocytomas

Replication-dependent H3.1 and H3.2 histones are encoded by 11 genes. The H3 mRNA levels in brain astrocytomas using real-time RT-PCR assay was examined. The sequence of primers and probe used in amplification was designed basing on the reference sequence GenBank accession no. The H3 mRNA levels correlated with tumor grade (R=0.56, P=0.0012), Ki-67 proliferative antigen labeling index (R=0.58, P=0.0008) and patient survival time (R=-0.50, P=0.005), discriminating low-grade and high-grade tumors. Quantification of H3 mRNA with real-time RT-PCR using the proposed pair of primers may supplement classic proliferative tests and predictive factors in brain astrocytomas.     

Linkage disequilibrium of three polymorphic RFLP markers in the apolipoprotein AI-CIII gene cluster on chromosome 11

A panel of glial tumors consisting of 11 low grade gliomas, 9 anaplastic gliomas, and 29 glioblastomas were analyzed for loss of heterozygosity by examining at least one locus for each chromosome. The frequency of allele loss was highest among the glioblastomas, suggesting that genetic alterations accumulate during glial tumor development. The most common genetic alteration detected involved allele losses of chromosome 10 loci; these losses were observed in all glioblastomas and in three of the anaplastic gliomas. In order to delineate which chromosome 10 region or regions were deleted in association with glial tumor development, a deletion mapping analysis was performed, and this revealed the partial loss of chromosome 10 in eight glioblastomas and two of the anaplastic gliomas. Among these cases, three distinct regions of chromosome 10 were indicated as being targeted for deletion: one telomeric region on 10p and both telomeric and centromeric locations on 10q. These data suggest the existence of multiple chromosome 10 tumor suppressor gene loci whose inactivation is involved in the malignant progression of glioma.     

Apolipoprotein D expression in primary brain tumors: analysis by quantitative RT-PCR in formalin-fixed, paraffin-embedded tissue.

Apolipoprotein D (apoD) expression has been shown to correlate both with cell cycle arrest and with prognosis in several types of malignancy, including central nervous system astrocytomas and medulloblastomas. ApoD expression was investigated by real-time quantitative RT-PCR using RNA extracted from 68 formalin-fixed, paraffin-embedded brain specimens. Glyceraldehyde phosphate dehydrogenase was used as an internal control. Quantitation was achieved on all specimens. Sixteen poorly infiltrating WHO grade I glial neoplasms (i.e., pilocytic astrocytomas and gangliogliomas) showed an average 20-fold higher apoD expression level compared with the 20 diffusely infiltrating glial neoplasms (i.e., glioblastoma, anaplastic astrocytoma, oligodendrogliomas; p=0.00004). A small number of exceptions (i.e., two high-expressing glioblastomas and three low-expressing gangliogliomas) were identified. Analyzed as individual tumor groups, poorly infiltrating grade I pilocytic astrocytomas and gangliogliomas differed significantly from each tumor type within the diffusely infiltrating higher-grade category (p<0.05 for each comparison) but not from each other (p>0.05). Conversely, each individual tumor type within the diffusely infiltrating category differed significantly from both pilocytic astrocytomas and gangliogliomas (p<0.05) but did not vary from other infiltrating tumors (p>0.05). Ependymomas, non-infiltrating grade II neoplasms, expressed levels of apoD similar to or lower than levels expressed by the diffusely infiltrating gliomas. Ten medulloblastomas with survival longer than 3 years averaged slightly higher apoD expression than four fatal medulloblastomas; however, this result was not statistically significant and individual exceptions were notable. In 17 of the medulloblastomas, MIB-1 proliferation rates quantitated by image cytometry did not correlate with apoD expression. In addition, apoD expression was 5-fold higher in the slowly proliferating grade I glial neoplasms compared with non-proliferating normal brain tissue (p=0.01), suggesting that apoD expression is not simply an inverse measure of proliferation. ApoD expression measured by quantitative RT-PCR may be useful in the differential diagnosis of primary brain tumors, particularly pilocytic astrocytomas and gangliogliomas.     

Epithelial differentiation in gliomas,meningiomas and choroid plexus papillomas

The immunohistological findings using antibodies to different intermediate filaments (glial fibrillary acidic protein, vimentin and two types of cytokeratin) and epithelial membrane antigen are described in 89 gliomas, 19 meningiomas and 8 choroid plexus papillomas (CPPs) from adult patients. All the patients had total or subtotal surgical excision of their tumours with clinical follow up for between 3 and 7 years. The immunohistological results were correlated with the histological features and patient survival. Tumours other than low grade astrocytomas, oligodendrogliomas and anaplastic ependymomas expressed one or more epithelial markers. This immunohistological evidence of epithelial differentiation in the absence of histological epithelial features in gliomas confirms that the two are not necessarily correlated. It is concluded that the expression of epithelial markers in some intradural tumours may reflect aberrant differentiation related to the degree of anaplasia in poorly differentiated astrocytomas and glioblastomas. All the patients with anaplastic epithelial marker-positive gliomas died within 1 year, whereas only 68% of patients with marker-negative tumours died within the follow-up period. In ependymomas and meningiomas, the expression of epithelial markers may reflect their histogenesis, while in malignant CPPs such expression could denote either their aberrant differentiation or histogenetic derivation.     

The expression of the epitope H recognized by the monoclonal antibody H is higher in astrocytomas compared to anaplastic astrocytomas and glioblastomas

The epitope H contains an O-linked N-acetylglucosamine residue in a specific conformation and/or environment recognized by the monoclonal antibody H (mAbH). mAbH stains two bands with Mr x0.001 of 209 and 62 in lysates of cultured rat astrocytes. In normal human brains epitope H is absent from the overwhelming majority of normal astrocytes and only sparse reactivity is observed, confined mostly to fibrous astrocytes. Upregulation of the epitope H takes place in reactive astrocytes. In the present study we used the mAbH to investigate the immunohistochemical expression of the epitope H in 41 cases of astrocytic tumors including 19 cases of astrocytomas, 8 cases of anaplastic astrocytomas and 14 cases of glioblastomas. Seven out of 19 cases (37%) of astrocytomas showed weak staining, 10 cases (53%) moderate staining and 2 cases (10%) intense staining. Two out of 8 cases (25%) of anaplastic astrocytomas appeared negative, 3 cases (37.5%) showed weak staining and 3 cases (37.5%) moderate staining. Four out of 14 cases (28.5) of glioblastomas appeared negative, 7 cases (50%) showed weak staining, 2 cases (14%) showed moderate staining and only one case (7.5%) showed intense staining. There was a statistically significant elevation of the expression of the epitope H in astrocytomas compared to anaplastic astrocytomas and glioblastomas (p=0.047). These results indicate that the expression of the epitope H decreases in parallel with the increase of the grade of astrocytic tumors from low to higher grade neoplasms. This could be of interest for predicting the progression of an astrocytic tumor since it is documented that astrocytomas progress to tumors of higher grade of malignancy. Further investigation of the antigens bearing the epitope H might help to gain further insight into the mechanisms which regulate the progression of astrocytic tumors and to examine the relevance of the mAbH staining with respect to the prognosis of these neoplasms.     

Claudins and ki-67: potential markers to differentiate low- and high-grade transitional cell carcinomas of the urinary bladder

Updated classification of urothelial cell cancer differentiates low-grade and high-grade cancers, which determines potential clinical outcome. Substantial interobserver variability necessitates new biomarkers to ensure classification. Claudins' specific expression pattern characterizes normal tissues, different tumor types, and defined grades of tumor differentiation. The aim of this study was to examine the expression pattern of claudins and proliferation marker Ki-67 in low-grade and high-grade urothelial cell cancers compared with independent control samples of non-tumorous urothelium, as well as to reveal the predictive usefulness of claudins. The expression of claudins-1, -2, -3, -4, -5, -7, and -10 and Ki-67 was studied with quantitative immunohistochemistry and real-time RT-PCR with relative quantification in 103 samples: 86 urothelial cell cancers (27 low grade, 59 high grade) and 17 non-tumorous urothelia. Results were analyzed regarding overall survival and recurrence-free period as well. High-grade tumors overall showed significantly higher claudin-4 and Ki-67 and significantly lower claudin-7 expression when compared with low-grade ones. High-grade tumors revealed significantly shorter overall survival in Kaplan-Meier analysis. Claudin-4, claudin-7, and Ki-67 might be used as potential markers to differentiate low-grade and high-grade urothelial cell cancers, thereby possibly enhancing accuracy of pathological diagnosis and adding further information to clinical outcome.     

Analysis of the BRAFV600E Mutation in Central Nervous System Tumors

BRAF^V600E mutations are involved in the development of melanoma, colon cancer, and papillary thyroid carcinoma. These mutations are also found in primary brain tumors at low to moderate frequencies. In this study, we investigated a series of brain tumors to determine the prevalence and associated clinicopathologic features of BRAF^V600E mutations. By direct sequencing, we analyzed 223 brain tumors, including 51 gangliogliomas (GGs), 45 pilocytic astrocytomas (PAs), 12 pleomorphic xanthoastrocytomas (PXAs), 35 glioblastomas (GBs), 28 anaplastic astrocytomas (AAs), 44 oligodendroglial tumors (ODGs), 3 anaplastic oligoastrocytomas, and 5 diffuse astrocytomas. Thirty-six cases (16.1%) exhibited the BRAF^V600E mutation, including 66.7% of PXAs, 23.5% of GGs, 15.6% of PAs, and 9.7% of the malignant gliomas; the latter included 14.3% of AAs, 8.6% of GBs, and 4.5% of ODGs. Copy number aberration at the 7q34 (BRAF) locus was found in 73.1% of PAs and 50% of PXAs. 9p Homozygous deletion was found in 66.7% of PXAs, but it was not correlated with the BRAF^V600E mutation. Patients' age, sex, histologic grade, and progression-free survival were also not correlated with the BRAF^V600E mutation. The BRAF^V600E mutation in brain tumors did not have prognostic value but is certainly a diagnostic marker and therapeutic target, not only for pediatric low-grade gliomas but also for malignant gliomas, even though the rate of mutation was not high. These results should be verified in a larger study with more cases and a longer follow-up period to overcome the limitation of small sample size.     

EGFR gene amplification in glioblastomas. Is there a relationship with morphology of tumor cell nuclei and proliferative activity?

OBJECTIVE: To confirm a relationship between histomorphology of glioblastomas and amplification of the gene for the epidermal growth factor receptor (EGFR) as the most important molecular biologic alteration in these tumors. STUDY DESIGN: In paraffin sections of surgical specimens from 71 primary resected glioblastomas, tumor cell nuclei in the region with the highest proliferative activity (Ki-67 immunostaining) were investigated morphometrically. Shape variables (roundness factor, Fourier amplitudes) and nuclear area were measured. Additionally, the numerical density of Ki-67-positive tumor cell nuclei was estimated. Differential polymerase chain reaction (PCR) was performed from paraffin sections of the same tumor area. The signals for the EGFR gene and IFN gamma reference gene were quantified densitometrically. RESULTS: Cases with distinct EGFR gene amplification (EGFR/IFN ratios > 5) revealed significantly lower mean values for several Fourier amplitudes, indicating a more regular nuclear shape when compared with cases without evidence of EGFR gene amplification (EGFR/IFN-ratios < or = 1). The Ki-67 index and nuclear area showed no significant differences between these groups. Although a large variation in nuclear morphology was observed for cases without evidence of EGFR gene amplification, discriminant analysis based on morphometric variables provided a good separation of these cases from cases with distinct EGFR gene amplification, with a high percentage of statistically correct reclassified cases. CONCLUSION: Our results provide evidence of a relationship between genetic alterations and histomorphology of glioblastomas.     

Ki-67 and AgNOR proliferative markers as diagnostic adjuncts to fine needle aspiration cytology of thyroid follicular lesions

OBJECTIVE: To differentiate hyperplastic nodules (HPN), follicular adenoma (FA) and follicular carcinoma (FCA) of the thyroid by cytomorphologic features combined with argyrophilic nucleolar organizer regions (AgNORs) and Ki-67 proliferative markers on fine needle aspiration cytology. STUDY DESIGN: Cytomorphologic patterns, along with two proliferation markers, Ki-67 and AgNORs, in fine needle aspirates of 123 histologically confirmed cases of thyroid follicular lesions, including 39 hyperplastic nodules, 70 follicular adenomas and 14 cases of follicular carcinomas, were recorded. RESULTS: Mean AgNOR (mAgNOR) counts and Ki-67 labelling index (LI) were consistently higher in FCA in comparison to FA and HPN irrespective of the cytologic patterns in fine needle aspiration smears. Between benign and malignant lesions, an overlap of 1.83% at the cutoff point of 4.0 was observed in cases of mAgNORs, whereas it was 11.09% at a cutoff of 5.0 in cases of Ki-67 LI. CONCLUSION: mAgNOR counting in fine needle aspiration smears is more sensitive, simple and cost effective as compared to Ki-67 LI for differentiating between benign and malignant thyroid follicular neoplasms.