DNA ploidy analysis in salivary gland tumours by image cytometry

AIM: To determine whether DNA ploidy by image cytometry is a good diagnostic tool to distinguish benign and malignant salivary gland tumours. METHODS: A total of 62 salivary gland tumours were studied. Cases were histologically diagnosed [haematoxylin and eosin (H&E)]. According to the World Health Organization (WHO) classification, there were 14 mucoepidermoid carcinomas (MEC), 11 adenoid cystic carcinomas (ACC), 10 pleomorphic adenomas (PA), 10 carcinoma ex PA (CEPA), 9 acinic cell carcinomas (ACCa), 3 polymorphous low-grade adenocarcinomas (PLGA), 2 papillary cystadenocarcinomas (PC), 1 myoepithelial carcinoma (MC), 1 undifferentiated carcinoma (UC) and 1 mucinous adenocarcinoma (MA). Paraffin sections (40 microm) were micro-dissected to isolate tumour areas; cell nuclei were extracted and Feulgen-stained cytospin monolayers were analysed using a DNA image cytometry system. For each case, DNA index (DI) was calculated relative to internal controls (lymphocytes; DI=1.0). Cases were categorized as diploid or aneuploid and the proportion of cells over 5c was also calculated. RESULTS: Fifty-three of 62 salivary gland tumours were uniformly diploid. Only nine cases were aneuploid: five CEPA, one low-grade MEC, one PC, one UC and one MA. CONCLUSIONS: The vast majority of salivary gland tumours were diploid. High-grade malignancies may be aneuploid, and ploidy may be useful to identify malignant change in atypical PA. Further, larger studies are needed to confirm our results and to further evaluate the usefulness of the technique in high-grade lesions.     

Clinicopathological features and proliferation markers in tongue squamous cell carcinomas

The aim of this study was to evaluate the clinicopathological features and immunohistochemical expression of proliferation markers in oral tongue squamous cell carcinomas (OTSCC). Sixty-three patients without previous treatment or distant metastases were selected. Clinical information was retrieved from medical charts, histopathological analysis was performed and expression of proliferation markers (Ki-67, Mcm-2 and geminin) was evaluated. Most patients were men (81%) (male:female ratio 4.25:1). The age range was 31-92 years (mean 57.6 ± 11.81 years). A high Anneroth score was associated with tumour size (p = 0.05), tumoural embolization of the blood vessels (p = 0.003), nodal metastasis (p = 0.05), nodal capsule rupture (p = 0.016) and distant metastasis (p = 0.002). Elevated Bryne scores were significantly associated with nodal capsule rupture (p = 0.02), distant metastasis (p = 0.002), shorter overall survival (OS) (p = 0.03) and disease-free survival (DFS) (p = 0.05) compared with patients with lower score. Elevated Ki-67+ cells (p = 0.05) and Mcm-2+ cells (p = 0.008) were associated with nodal metastasis and tumours with a high geminin score demonstrated a significant tendency for neural invasion (p = 0.05). Anneroth and Bryne score in association with biomarkers of proliferation can be useful for evaluating the biological behaviour of OTSCC.     

PCNA, Ki-67 and p53 expressions in submandibular salivary gland tumours

Salivary gland tumours are uncommon with a broad heterogeneity. The most common benign tumour is the pleomorphic adenoma, whereas mucoepidermoid carcinoma and adenoid cystic carcinoma predominate among the malignancies. Most salivary gland tumours occur in the parotid, and consequently clinical and biological data are normally derived from this site. This work describes the expressions of PCNA, Ki-67 and p53 in 15 pleomorphic adenomas, 15 mucoepidermoid carcinomas and 15 adenoid cystic carcinomas of the submandibular gland. Our results showed that all pleomorphic adenomas were negative for p53 and Ki-67 with 66.6% being positive for PCNA. Conversely, p53 was positive in 53% of the mucoepidermoid carcinomas and in 20% of the adenoid cystic carcinomas. Ki-67 was expressed in 47.7% of the mucoepidermoid carcinomas and 40% of the adenoid cystic carcinomas. All malignant tumours were positive for PCNA. These results indicate that the proliferative rate analysed with PCNA and Ki-67 and the expression of p53 in pleomorphic adenoma and adenoid cystic carcinoma of the submandibular gland were similar to those described in the parotid and minor salivary glands. However, mucoepidermoid carcinomas showed higher expression of these markers than those of other salivary glands. This work is the first describing the expression of these immunohistochemical markers exclusively in submandibular salivary gland tumours.     

Angiogenic and lymphangiogenic microvessel density in recurrent pleomorphic adenoma

Background:  Recurrent pleomorphic adenoma (RPA) is an uncommon and challenging disease. The aim of this study was to determine if there is a difference between RPA and the pleomorphic adenoma (PA) without recurrence related to tumor blood and lymphatic vascularization. Moreover, we compared the microvessel density (MVD) between cell-rich areas (predominance of epithelial cells) and cell-poor areas (predominance of myxoid and chondroid areas) of the stroma of PA and RPA. In addition, immunohistochemical staining for the Ki-67 antigen was conducted simultaneously to evaluate cell proliferation in PA and RPA.
Methods:  A total of 19 cases of PA and 24 cases of RPA, blood, and lymphatic vessels were analyzed by immunohistochemical technique using the antibodies CD34, CD105, D2-40, and Ki-67.
Results:  Comparing no recurrent with recurrent tumor, no significant difference was found in terms of lymphatic vessel density, MVD, and proliferation index. When MVD and proliferation index were compared with different areas in cellular composition (cell-rich and cell-poor areas), there was a significant difference in PA, as well as in RPA.
Conclusion:  This study shows that although RPA presents more aggressive clinical behavior than PA, there is no difference between tumor blood and lymphatic vascularization, suggesting that there is no correlation between vascularity and risk of recurrence. Furthermore, vascularized stroma in PA, as well as RPA, depends on the proportion of the cellular composition.     

A fluorescence in situ hybridization (FISH) analysis with centromere-specific DNA probes of chromosomes 3 and 17 in pleomorphic adenomas and adenoid cystic carcinomas

Aberrations of chromosomes 3 and 17 were studied by FISH using centromere-specific DNA probes in 11 salivary adenoid cystic carcinomas (ACC) and 8 salivary pleomorphic adenomas (PA), with 3 lymph nodes as controls. Two hybridized signals were detected in 92.8±2.7% of controls, 73.2±7.0% of PA and 66.8±7.9% of ACC cells for chromosome 3, and in 90.4±2.3% of controls, 59.5±25.0% of PA and 44.8±20.2% of ACC for chromosome 17. More than 3 hybridized signals, which indicate polysomy, were observed in 3.1% of controls, 15.5% of PA and 22.9% of ACC cells for chromosome 3, and in 1.2% of controls, 10.3% of PA and 23.1% of ACC cells for chromosome 17. A single hybridized signal was much more frequent for chromosome 17 than for chromosome 3. These findings suggest that polysomy of both chromosomes occurs during the development of salivary gland tumors, and its frequency is increased in adenoid cystic carcinoma as compared to pleomorphic adenoma. In addition, monosomy of chromosome 17 could possibly be significant in salivary gland tumors.     

Ki-67 expression in non-tumour epithelium adjacent to oral cancer as risk marker for multiple oral tumours

Objective:  The aim of this study was to determine whether the differential assessment of epithelial proliferation is useful to diagnose premalignant fields and assess the risk of multiple tumours.
Material and methods:  We analysed 83 oral carcinomas with associated non-tumour epithelium classified as distant or close according to its distance (> or <1 cm) from the invasion point, and as squamous hyperplasia, mild, moderate, severe dysplasia or carcinoma in situ . Twenty-five healthy oral mucosa samples were used as controls. An immunohistochemical technique was applied using Mib-1. Ki-67 in premalignant epithelium was assessed in basal layer, parabasal layer, medium and upper third.
Results:  Parabasal expression was significantly higher or showed a tendency to be higher in close and distant epithelia with any histological grade than in the controls. Parabasal Ki-67 significantly differed between distant epithelia associated with multiple vs single tumours ( P  < 0.001) and between distant epithelia associated with multiple tumours vs controls ( P  < 0.001). This difference was not observed between distant epithelia associated with single tumours and controls ( P  = 0.175). The cut-off point that differentiated epithelia associated with multiple tumours was >50% of Ki-67 + parabasal cells in distant epithelia, which yielded 0.88 sensitivity and 0.79 specificity.
Conclusions:  The concept of a precancerous field may be linked to an increase in the proliferative activity of parabasal cells.     

Analysis of the Ki-67 antigen at the invasive tumour front of human oral squamous cell carcinoma

BACKGROUND: It is hypothesised that cell proliferation, as measured by the Ki-67 labelling index (LI) at the invasive tumour front (ITF) was directly related to the histological grade in human oral squamous cell carcinomas (SCCs). METHODS: Tissues from 42 human oral SCCs were collected and stained with an antibody directed against the Ki-67 antigen using an advanced polymer staining system. Quantitation of the immunopositive cells was performed on two parallel sections at the invasive tumour front (ITF), using an image analyser. The Ki-67 LI was expressed as the number of positive nuclei/mm2 of epithelium. The control tissue used was normal epithelium at the excision margin. RESULTS: The mean Ki-67 LI for oral SCCs at the ITF was significantly greater than that for the excision margin tissue (P < 0.0001). There was a positive association between increasing Ki-67 LI and increasing Broders' grade (P < 0.05), with a well-differentiated tumour having the lowest mean Ki-67 LI (1549 +/- 806) and a poorly differentiated tumour having the highest value (2232 +/- 771). A similar trend was observed between the mean Ki-67 LI and Bryne's multifactorial grading system. CONCLUSIONS: It was concluded from this study that cell proliferation (as measured by the Ki-67 antigen) at the ITF had a strong positive relationship with histological grading in human oral SCC.     

Multiple tumours of the salivary glands—Terminology and nomenclature

Multiple tumours of the salivary glands are very rare and their combinations according to histological classification of the tumours, localisation and origin (origin in independent topographical areas or in the same tissue) are diverse.The following two categories can be distinguished: common occurrence of multiple salivary gland tumours with identical histology, or with different histology. In either group the tumours can be unilateral or bilateral, synchronous or metachronous. The most common multiple tumours with an identical histology are Warthin tumours and pleomorphic adenomas. Bilateral occurrence has been observed especially in oncocytomas, acinic cell carcinomas and basal cell adenomas. In the group of multiple tumours with differing histology, Warthin tumours and pleomorphic adenomas show a number of combinations with other adenomas or carcinomas of the salivary glands. Notable also is the simultaneous occurrence of salivary gland tumours with other oral tumours or extraglandular tumours, especially thyroid carcinomas and breast carcinomas.Multiple salivary gland tumours must be distinguished by nomenclature from tumours with biphasic differentiation and hybrid tumours. Tumours with biphasic differentiation are defined as regular, recurring mixtures of two cellular components in the same tumour and have a corresponding term in the tumour classification. Hybrid tumours are very rare and are composed of two different tumour entities within the same topographical area. Each of the tumour entities conforms with an exactly defined tumour category.     

The relationship of proliferating cell density at the invasive tumour front with prognostic and risk factors in human oral squamous cell carcinoma

BACKGROUND: We hypothesise that the density of proliferating cells at the invasive tumour front (ITF) has a positive relationship with prognostic and risk factors in human oral squamous cell carcinoma (SCC). METHODS: Tissues from 47 human oral SCC specimens were collected and stained with a monoclonal antibody directed against the Ki-67 antigen using a horseradish peroxidase based two-step immunostaining method. Counting was performed on two parallel sections at the ITF using an image analyser. The Ki-67 labelling index (LI) was determined by measuring the number of nuclei/mm(2) of epithelium. RESULTS: Our results show that the density of proliferating cells is related to clinical staging, with advanced stage of disease having a significantly higher Ki-67 LI compared with early stage of disease (2111 +/- 905 vs. 1908 +/- 913; P = 0.03). Importantly, this study shows that tumours that have metastasised have a significantly higher Ki-67 LI than tumours where distant metastasis was not detected (3257 +/- 650 vs. 1966 +/- 881; P < 0.0001). CONCLUSIONS: Cell proliferation, as measured by the Ki-67 LI at the ITF, has a positive relationship with clinical staging, tumour thickness, smoking status of the patient and alcohol consumption. Further, we suggest that a multicenter study with a large cohort of patients is indicated to fully elucidate whether cell proliferation at the ITF is directly related to patient survival.     

Immunohistochemical detection of DNA topoisomerase type II α and Ki-67 in adenoid cystic carcinoma and pleomorphic adenoma of the salivary gland

Immunohistochemical detection of cell proliferation-associated antigens was investigated in 28 cases of adenoid cystic carcinoma (ACC) and 20 cases of pleomorphic adenoma (PA), using antibodies against DNA topoisomerase type II alpha (topo-II) (Ki-S1) and Ki-67 (MIB-1). The correlation of staining indices with clinicopathological data, histological features and prognosis was also studied. The topo-II value was significantly higher in ACC than in PA (P<0.0001), and highest in the solid growth pattern of ACC. In addition, significant relationships were found between topo-II values and clinical features such as local recurrence, surgical margins, and distant metastases. By log-rank test, the topo-II index was also correlated significantly with patient survival (P<0.01). The values of topo-II index paralleled those of Ki-67 index in ACC, and a correlation coefficient of 0.97 was obtained. Topo-II may be considered an additional marker for estimating the proliferating fraction of cells and for predicting the short-term prognosis for patients with salivary gland tumors.     

Prognostic factors for keratocystic odontogenic tumor (odontogenic keratocyst): analysis of clinico-pathologic and immunohistochemical findings in cysts treated by enucleation

Background:  The purpose of this study was to determine prognostic factors for the recurrence of keratocystic odontogenic tumors (KCOTs) following simple enucleation by examining clinico-pathologic and immunohistochemical findings.
Methods:  Following enucleation, the frequency of recurrence among 32 subjects diagnosed with KCOT was analyzed for tumor site, radiographic and histologic features, and immunopositivity for Ki-67 and p53.
Results:  Keratocystic odontogenic tumors in four out of 32 subjects (12.5%) recurred during the follow-up period (median: 33 months, range: 7–114 months). Three out of four subjects (75.0%) among recurrent group showed high expression of Ki-67 (LI >10%) in basal layer and four (4/28; 14.3%) among non-recurrence group ( P  = 0.025). Expression of p53 among non-recurrent group was observed in 11 subjects (11/28; 39.3%), and in three subjects (3/4; 75.0%) among the recurrent group ( P  = 0.295). Hazard risk for the recurrence of KCOT was 4.02 (95% CI 1.42–18.14) for high Ki-67 expression in the basal layer by the Cox proportional hazard model ( P   =  0.009). In our study, none of the other clinico-pathologic variables were associated with the recurrence of KCOT.
Conclusion:  The results suggested that the evaluation of Ki-67 expression in KCOT at the time of pathological diagnosis might be helpful for consideration of appropriate adjunctive surgical procedures to avoid a recurrence and may serve as a prognostic marker.     

细胞外基质金属蛋白酶诱导因子表达与唾液腺肿瘤侵袭性的关系

目的:检测唾液腺肿瘤组织中细胞外基质金属蛋白酶诱导因子(EMMPRIN)的表达和定位,探讨其与唾液腺肿瘤侵袭性生物学行为的关系。方法:采用免疫组织化学方法,检测9例唾液腺正常组织、28例多形性腺瘤(PA)、25例黏液表皮样癌(MC)、33例腺样囊性癌(ACC)中EMMPRIN的表达和定位。采用SPSS10.0软件包进行多个样本率间的χ2检验或确切概率分析。结果:EMMPRIN在正常唾液腺组织、多形性腺瘤、黏液表皮样癌、腺样囊性癌的表达阳性率分别为11.11%、53.71%、84.00%和90.91%(P<0.05)。在正常唾液腺组织的表达主要见于导管上皮细胞的细胞膜;EMMPRIN蛋白在多形性腺瘤、黏液表皮样癌、腺样囊性癌的表达见于肿瘤细胞的胞膜或胞质。腺样囊性癌嗜神经现象组中,EMMPRIN表达的阳性率高于无嗜神经现象组,但差异无统计学意义。结论:EMMPRIN的表达与唾液腺肿瘤侵袭性生物学行为密切相关。     

Proliferative activity of salivary gland pleomorphic adenomas and myoepitheliomas as evaluated by the proliferating cell nuclear antigen (PCNA) labeling index (LI)

Thirteen examples of pleomorphic adenoma (PA) and 4 of myoepithelioma (Me, 2 plasmacytoid cell type, 2 mixed cell type) were examined with respect to their proliferative activity on the basis of proliferating cell nuclear antigen (PCNA) immunohistochemistry. In PA, PCNA labeling index (LI) in tubular/trabecular/solid areas was significantly higher than that in myxomatous or chondroid areas. Although the mean value of LI in PA and Me was not statistically different (PA; 3.02±1.03%, Me; 3.19±1.76%), the Me of mixed cell type composed of epithelial, spindle or clear neoplastic myoepithelial cells had significantly higher LI, indicating the possibility of more rapid growth than PA. The small difference in the mean value of PCNA LI between PA and the mixed cell type of Me, however, suggests that enucleation with a margin of normal uninvolved tissue remains the recommended treatment for Me, as well as for PA.     

Demonstration of c-erbB-2 oncogene overexpression in salivary gland neoplasms by in situ hybridization

The level of c-erbB-2 cellular mRNA in 18 salivary gland tumours and in 7 normal salivary glands was determined by in situ hybridization using [³⁵S] labelled RNA probes. Computer assisted quantitation of the autoradiographic signal indicated a significantly higher c- erb B-2 expression in the tumour group (22.64 grains per cell ±3.79; 95% CI) as compared to the non-neoplastic salivary gland tissue (4.11 ±0.90; 95% CI). The c-erbB-2 expression as measured by grain counts per cell for the pleomorphic adenomas (16.29± 1.87; 95% CI), mucoepidermoid carcinomas (31.52 ±0.08; 95% CI) and the acinic cell carcinomas (44.24± 17.11; 95% CI) were significantly greater than the expression for the normal group. The acinic cell carcinomas exhibited the greatest level of expression. As observed at the individual cell level, the autoradiographic signal was distributed uniformly in the neoplastic tissues, regardless of the cell type. This study confirms the hypothesis that the c-erb B-2 oncogene is overexpressed at the mRNA level in salivary gland tumours.     

Expression of C-X-C motif chemokine receptors 4 and 7 in salivary gland neoplasms

ObjectivesChemokine receptors have been shown to overexpress in several cancer types. Binding of chemokines to their cognate chemokine receptors on tumor cells can promote tumor growth, angiogenesis and metastasis. The purposes of this study was to examine the expression of chemokine receptors, CXCR4 and CXCR7, in salivary gland neoplasms and its association with pathologic characteristics.DesignSixty-two cases of salivary gland neoplasms, including 25 mucoepidermoid carcinomas (MEC), 18 adenoid cystic carcinomas (ACC), 14 pleomorphic adenomas (PA) and 5 polymorphous low-grade adenocarcinoma (PLGA) were investigated for CXCR4 and CXCR7 expression immunohistochemically. The immunoreactivity was categorized as low expression or high expression group, based on whether the positive staining was below or higher than 50% of the neoplastic cells, respectively.ResultsThe majority of MECs, ACCs and PLGAs showed high CXCR4 and CXCR7 expression, whereas most PAs showed high CXCR4 but low CXCR7 expression. The levels of CXCR4 and CXCR7 expression were significantly correlated. In MECs, the expression of both chemokine receptors was localized to squamous cells, intermediate cells and glandular epithelial cells, whereas mucous cells and clear cells were negative. In ACCs and PAs, their immunoreactivity was more intense in ductal cells than myoepithelial cells. Most neoplastic myoepithelial cells in PAs did not express CXCR7, while those in ACCs showed strong CXCR7 expression. The increased CXCR4 expression was significantly associated with advanced pathologic grade of MECs (P = 0.03).ConclusionOverexpression of CXCR4 and CXCR7 is common in the 4 salivary gland neoplasms investigated. CXCR4 may play a role in the progression of MECs.     

Misleading initial histological diagnosis of a polymorphous low-grade adenocarcinoma in situ ex pleomorphic adenoma—a case report

Introduction

Polymorphous low-grade adenocarcinoma (PLGA) are frequent tumours of palatinal minor salivary glands. They appear clinically as solid mass located beneath intact surface epithelium, thus quite similar with benign neoplasm. PLGA displays a low tendency of aggressive behaviour. The correct aetiology of this disorder is still unknown.

Case report

In this contribution, a PLGA is reported which was located in a pleomorphic adenoma (PA). Out of an initially incisional biopsy, only the benign part of the lesion was diagnosed. Definitive histological examination of the whole tumour revealed a small malignant fraction of the specimen besides a major part of benign tissue formations (PA).

Conclusion

This case shows the uncertain confidence of incisional biopsy, the variably biologic behaviour of PA, providing hints for consideration of the PLGA aetiology and highlights both the necessity to remove whole PA-like lesions as well as to perform systematically histological examination of whole specimens.     

Differential expression of galectin-3, β-catenin, and cyclin D1 in adenoid cystic carcinoma and polymorphous low-grade adenocarcinoma of salivary glands

Background:  Galectin-3 has been implicated in tumor progression of some malignancies as thyroid, prostate, and salivary gland tumors. Recently, it has been suggested that this protein may be an important mediator of the β-catenin/Wnt pathway. Moreover, nuclear galectin-3 expression has been implicated in cell proliferation, promoting cyclin D1 activation. Thus, the present study aimed to correlate galectin-3 expression with β-catenin and cyclin D1 expressions in adenoid cystic carcinoma (ACC) and in polymorphous low-grade adenocarcinoma (PLGA).
Methods:  Fifteen formalin-fixed paraffin-embedded cases of each tumor were retrieved from the files of the Surgical Oral Pathology Service at the University of São Paulo and the proteins were analyzed by immunohistochemistry.
Results:  Adenoid cystic carcinoma showed galectin-3 immunostaining mainly in the nuclei, while PLGA revealed a positive mostly cytoplasmic reaction to galectin-3 in the largest part of tumor cells. Both tumors showed intense cytoplasmic/nuclear staining for β-catenin in majority of cases. Cyclin D1 immunoreactivity was not detected in 14/15 PLGA and showed specific nuclear staining in 10/15 cases of ACC in more than 5% of the neoplastic cells. Cyclin D1 expression was correlated with cytoplasmic and nuclear galectin-3 expression in ACC ( P  < 0.05).
Conclusions:  These results suggest that in ACC galectin-3 may play a role in cellular proliferation through cyclin D1 activation. In addition, nuclear expression of galectin-3 in ACC may be related to a more aggressive behavior of this lesion. Although β-catenin seems to play a role in carcinogenesis in both lesions, it seems that it does not bind to galectin-3 for cyclin D1 stimulation.     

A immunohistochemical study of the peripheral ameloblastoma

AIM: Peripheral ameloblastoma (PA) is a rare variant of ameloblastoma occurring in the extraosseous region. With regard to the histogenesis of the tumor, two major sources of origin are considered: odontogenic epithelial remnants and the gingival epithelium. In this study, we examined the immunohistochemical profiles of cytokeratins (CKs) and Ki-67 labeling index (LI) of PAs, and discuss the histogenesis and the biologic behavior of the PA. MATERIALS AND METHODS: Eight cases of PA were retrieved from the pathology files of 212 cases of ameloblastoma that had been registered at our hospital. Immunohistochemical staining was performed in seven cases using monoclonal antibodies of six CKs (7, 8, 13, 14, 18, and 19) and Ki-67. RESULTS: All cases of PA expressed CK13, 14, and 19. CK18 was positive staining in six cases, and CK8 in five cases. This staining pattern was similar to that in intraosseous ameloblastomas (IAs). The mean of Ki-67 LI of PAs (1.91%) was significantly lower than that of IAs (4.82%) (P = 0.002). CONCLUSION: We consider that the PA originates from odontogenic epithelial remnants rather than from the gingival epithelium, and the Ki-67 LI of the tumor is a good prognostic indicator.     

Aberrant expression of cyclin A and cyclin B1 proteins in oral carcinoma

Cyclins play an important role in regulating the passage of dividing cells through critical checkpoints in cell cycle. Aberrant exprssion of cylcin proteins has been found in a number of human cancers, including carcinomas of the head and neck, where amplification of the cyclin D1 gene is a common finding. The obective of this study was to examine cell cycle kinetics in oral carcinomas by determining the expression the S phase protein cylcin A and the M phase protein cyclin B1. Routinely processed tissue sections of 50 oral squamous cell carcinomas from the floor of the mouth were stained by immunohistochemistry for cyclin A, cyclin B1 and Ki-67 proteins. Ten specimens of normal epithelium from the floor of the mouth were used as controls. Teh number of cells showing nuclear staining for cylin A, cyclin B1 and Ki-67 proteins was determined by computer image analysis. There were 17 well-differentiated, 25 moderately differentiated and 8 poorly differentiated tumours. Mean counts for cylcin A (29.50 ± 4.10, Mean ± 95% CI), cyclin B1 (2.05 ± 0.30) and Ki-67 (49.46 ± 5.91) protiens in the carcinomas were significantly higher than counts for the normal epithelial controls (cyclin A: 930 ± 1.72; cyclin B1: 1.01 ± 0.36; Ki-67: 17.4. ± 4.17). For cyclin A, cyclin B1 and Ki-67, mean staining scores fosr all tumour grades were significantly higher than controsl. There was a strong correlation between ki-67 and cyclin A scores in all tumour groups (r²=0.68); however, the correlations between cyclin B1 and Cyclin A Scores(r²=0.35) and between clylcin B1 and ki-67 scores (r²=0.39) were weak. We conclude that there is overexpression of cyclin A and cyclin B1 proteins in oral carcinoma. Furthermore, the poor correlations for cylcin B1 scores with other cell cycle indices suggest that there may be aberrant cell cycle progression at G2/M checkpoint in oral carcinomas.     

Keratinocyte growth factor colocalized with perlecan at the site of capsular invasion and vascular involvement in salivary pleomorphic adenomas

Background:  Capsular invasion is often observed in daily pathologic diagnosis of pleomorphic adenomas, although neither actual information about its occurrence nor molecular mechanisms leading to their invasive activities have been reported. In this study, our aim was to elucidate the mode and the frequency of capsular invasion in this tumor and to characterize the tumor cell arrangement at the site of capsular invasion.
Methods:  The mode and frequency of capsular invasion of salivary pleomorphic adenomas were histopathologically examined in 104 surgical specimens of pleomorphic adenoma, and stromal characteristics, and tumor cell arrangements at the sites of capsular invasion were immunohistochemically investigated.
Results:  A total of 353 areas with capsular invasive changes were collected from 104 cases. The mode of capsular invasion was classified into two types: type I: intracapsular invasion (247 areas, 70%) and type II: capsular penetration (106 areas, 30%). Myxoid stroma, which was perlecan-immunopositive (+), was shared by both type I and type II sites, while tumor cell foci containing ductal structures were predominant in type II sites. These foci were composed of KGF⁺ and FGFR2⁺ cells. In addition, apparent vascular involvement was recognized in 31 tumors (29.8%).
Conclusion:  The results suggest that pleomorphic adenoma cells are able to invade into the capsule and involve blood vessels when they are situated in perlecan-rich milieu, which accelerate KGF signaling.