Angiogenesis and Lymphangiogenesis in Salivary Gland Adenoid Cystic Carcinoma and Mucoepidermoid Carcinoma

BACKGROUND AND PURPOSE

This study aimed to investigate the immunohistochemical expression of CD31 and podoplanin in order to examine angiogenesis and lymphangiogenesis, respectively in common malignant tumors of salivary glands.

MATERIALS AND METHODS

Forty formalin-fixed, paraffinated blocks (20 adenoid cystic carcinoma and 20 mucoepidermoid carcinoma blocks) were selected from the medical archives of Amir A'lam Hospital of Tehran, Iran. Sections from the blocks were stained by CD31 and D2-40 markers via immunohistochemistry. Clinical and demographic information was extracted from the patients' records.

FINDINGS

There was a significant difference between tumors in terms of intratumoral microvessel density (MVD) (P< 0.001), total MVD (P< 0.001), and intratumoral lymphatic vessel density (LVD) (P= 0.011). In mucoepidermoid carcinoma, intratumoral MVD and LVD were greater than peritumoral MVD and LVD (P= 0.001 and P< 0.001, respectively). In mucoepidermoid carcinoma, there was no relationship between histological grade with MVD (total, intratumoral or peritumoral) or LVD (total, intratumoral or peritumoral) (P> 0.05). A similar finding was reported with respect to the histopathological grade of adenoid cystic carcinoma (P> 0.05).

CONCLUSION

The higher level of angiogenesis and lymphangiogenesis in mucoepidermoid carcinoma, specifically at the center of tumor, compared to adenoid cystic carcinoma, may be attributed to differences in the clinical behaviors and metastasis of tumors. Moreover, considering the high LVD at the center of tumor in mucoepidermoid carcinoma and infrequency of metastasis to regional lymph nodes in adenoid cystic carcinoma, it can play a significant role in metastasis to regional lymph nodes.

Vascular Pattern Analysis on Microvascular Sonography for Differentiation of Pleomorphic Adenomas and Warthin Tumors of Salivary Glands

OBJECTIVES

Pleomorphic adenomas and Warthin tumors are the most common salivary gland tumors. It is important to differentiate between them because at least a partial parotidectomy is necessary for pleomorphic adenomas, whereas enucleation is sufficient for Warthin tumors. This study aimed to evaluate the usefulness of vascular pattern analysis using microvascular sonography to differentiate between the tumors.

METHODS

Sixty-two patients with pathologically proven pleomorphic adenomas (n = 38) and Warthin tumors (n = 24) were included. For all tumors, grayscale, power Doppler, and microvascular sonographic examinations were performed. Differences in vascular patterns (vascular distribution and internal vascularity) on power Doppler and microvascular sonography as well as grayscale sonographic features (size, shape, border, echogenicity, heterogeneity, and cystic change) between pleomorphic adenomas and Warthin tumors were evaluated. A comparison of diagnostic performances of grayscale sonography with power Doppler sonography and grayscale sonography with microvascular sonography was performed. The level of interobserver agreement between 2 reviewers in diagnosing tumors was evaluated.

RESULTS

No grayscale sonographic features showed a significant difference between the tumors. Vascular distributions and internal vascularity on power Doppler sonography (P = .01 and .002) and microvascular sonography (both P < .001) were all significantly different. The diagnostic accuracy of grayscale sonography with microvascular sonography (79.0%) was higher than that of grayscale sonography with power Doppler sonography (72.6%). This difference was significant according to the McNemar test (P = .004). Interobserver agreement was excellent in diagnosing tumors on both grayscale sonography with power Doppler sonography (κ = 0.83) and grayscale sonography with microvascular sonography (κ = 0.94).

CONCLUSIONS

Vascular pattern analysis using microvascular sonography with other sonographic features is helpful for differentiating between pleomorphic adenomas and Warthin tumors.

Acinic cell carcinoma of the salivary glands: an immunohistochemical study of angiogenesis in 12 cases

Acinic cell carcinoma (ACC) is the third most common epithelial malignancy of the salivary glands in adults, exhibiting a low-grade malignancy that mainly occurs in the parotid gland and at a relatively younger age than other salivary gland tumors. We performed an immunohistochemically study regarding angiogenesis in ACC, by assessing the CD105+ tumor microvessels density and investigating the VEGF and its receptors VEGFR1 and VEGFR2 expression in tumor samples. The results indicated an active angiogenesis in ACC, with the highest CD105-MVD score recorded in the solid variant. This fact was supported by the reactivity of tumor cells and endothelial blood vessel cells for VEGF and its receptors (VEGFR1 and VEGFR2). Thus, we concluded that in ACC do exist autocrine and paracrine VEGF loops implicated in growth and progression of this kind of salivary gland tumors.

An analysis of microvessel density in salivary gland tumours: a single centre study

BACKGROUNDS

Microvessel density (MVD) can be used for determining neoplastic neovascularisation. Tumour angiogenesis correlates with prognosis of cancers in many organs. The aims of this study were to evaluate MVD as demonstrated by CD31 and CD105 in salivary gland tumours (SGTs), and to correlate the MVD results with clinicopathological characteristics of the tumours.

MATERIALS AND METHODS

Using a retrospective cohort study design, we enrolled SGTs patients at the Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand, over the 22-year period. The predictor variables included demographic, anatomic and histopathological parameters. The outcome measure was average CD31-MVD and CD105-MVD counted by the "hot spot" method. Descriptive, uni- and bivariate statistics were computed, and P <0.05 was considered statistically significant.

RESULTS

The study sample consisted of 43 subjects with a mean age of 39.6 ± 17.8 years (range, 9-82), including 26 females (60.5%), diagnosed with SGTs. In this cohort, 58.1% of the cases were benign, and 83.7% were minor SGTs. There was a significant correlation between CD31-MVD and CD105-MVD (r = 0.8, P < 0.001), but mean CD31-MVD and CD105-MVD were 17.7 ± 9.3 and 12.8 ± 7.4, respectively (P = 0.009). Age, gender and tumour site were not individually associated with significant differences between CD31-MVD and CD105-MVD. Tumours with myoepithelial cells had lower MVD than those without myoepithelial cells (P = 0.04 for CD31; P = 0.03 for CD105). Only CD105-MVD showed statistical difference between benign and malignant SGTs (P = 0.01).

CONCLUSIONS

These results suggest that MVD in SGTs can be demonstrated by CD31 and CD105. Despite a strong correlation, CD31-MVD is always higher than CD105-MVD and cannot differentiate between benign and malignant SGTs. The presence of myoepithelial cells within SGTs affects the MVD analysis using either CD31 or CD105, while age, gender and tumour location do not.

Premetastatic vasculogenesis in oral squamous cell carcinoma xenograft-draining lymph nodes

OBJECTIVE

To study vascular anatomy on oral cancer-draining lymph nodes before metastasis in mice.

MATERIAL AND METHODS

Cell lines: highly lymph metastatic oral squamous cell carcinoma SASL1m and non-metastatic human adenoid cystic carcinoma ACC2. Bone marrow transplants and xenografts: Nude mice were lethally irradiated and transplanted with bone marrow cells from EGFP(+) mice. SASL1m or ACC2 cells were implanted in the tongue. Non-xenografted mice were used as controls. In addition, we injected conditioned medium from SASL1m or ACC2 in transplanted mice. Immunohistochemistry: Primary tumors and neck lymph nodes were resected and stained with anti-mouse Podoplanin and CD31. Images were visualized in a confocal microscope. Image analysis: Areas covered by EGFP, CD31 and Podoplanin were measured and compared statistically. Expression microarrays: Transcriptomic microarray analysis compared SASL1 to ACC2 cells. Interactomes were generated to reveal altered pathways.

RESULTS

SASL1m cells induced the assemblage of blood vessels in cancer-free, tumor-draining lymph nodes. These blood vessels incorporated bone marrow-derived EGFP(+)CD31(+) cells. Notably, SASL1m-conditioned medium induced a similar reaction. Non-metastatic cells failed to produce any change. Microarray and pathway analyses revealed the upregulation of Transforming Growth Factor-β, Lysyl Oxidase-like 2, Slit homolog 3 and Protease Serine 22. The upregulation of these genes was confirmed in xenografts.

CONCLUSIONS

This study suggests that a blood supply for new tumors is established in lymph nodes before metastasis. It also suggests that premetastatic vasculogenesis and primary tumor angiogenesis may be mediated by different mechanisms.

Exogenous expression of caspase-14 induces tumor suppression in human salivary cancer cells by inhibiting tumor vascularization

BACKGROUND

Current therapeutic approaches to salivary gland cancer are often associated with severe disfigurement and loss of glandular function, which are traumatic to the patients. Exploration of novel treatment approaches, such as gene therapy, is needed.

MATERIALS AND METHODS

The human salivary gland cancer cell line HSG was transiently transfected with full length human caspase-14 cDNA. Photomicroscopy, BrdU assay, cell counting, MTT assay, and TUNEL assay were applied. To determine the tumorigenicity, tumor volume, tumor pathology and vascularization were analyzed in vivo.

RESULTS

Cell growth and viability were inhibited significantly by transient caspase-14 expression. Caspase-14 expression resulted in a significant reduction of tumorigenicity. Importantly, a significant decrease in tumor blood vessel formation was observed.

CONCLUSION

Salivary gland cancer cells underwent growth inhibition, cell death, and reduced tumorigenicity in vivo when exogenous caspase-14 was expressed, which could be due, in part, to an inhibitory effect of caspase-14 on tumor vascularization.

Expression of caveolin-1 in mucoepidermoid carcinoma of the salivary glands: correlation with vascular endothelial growth factor, microvessel density, and clinical outcome

BACKGROUND

Caveolin-1, which has been proposed as a candidate tumor suppressor, plays a regulatory role in several signaling pathways. The importance of caveolin-1 in endothelial cells in angiogenesis has been confirmed. The clinicopathologic significance of caveolin-1 expression and its correlation with angiogenesis remains unknown in mucoepidermoid carcinoma (MEC) of the salivary glands.

METHODS

Based on an immunohistochemical study, the expression levels of caveolin-1 and vascular endothelial growth factor (VEGF) and the intratumoral microvessel density (MVD) (labeled by CD34) in 75 patients with MEC were investigated, and correlations with clinicopathologic variables were evaluated statistically.

RESULTS

The expression rates of both caveolin-1 and VEGF were 54.7% (41 of 75 tumors). MVD varied from 9 to 56 (24.45 +/- 10.72)/x 200. Caveolin-1 expression was correlated inversely with duration of tumor, clinical stage, histologic grade, and MVD (P = .027, P = .011, P = .04, and P = .025; respectively). VEGF expression was associated positively with MVD (P = .000). Advanced clinical stage, higher grade, and tumors that originated from minor salivary glands exhibited higher MVD (P = .029, P = .002, and P = .008, respectively). The presence of clinical symptoms, male gender, advanced clinical stage, higher grade, increased MVD, and down-regulated caveolin-1 were correlated significantly with the development of recurrent disease, as indicated by a shorter disease-free interval (P < .05). Both univariate and multivariate analyses indicated that clinical stage, histologic grade, and MVD were independent prognostic factors (P < .05). The presence of clinical symptoms and the down-regulation of caveolin-1 were identified as negative prognostic predictors in the univariate analysis (P < .05) but did not achieve significance in the multivariate analysis (P > .05).

CONCLUSIONS

The current results suggest that caveolin-1 may function as a tumor suppressor in MEC of the salivary glands. Reduced expression of caveolin-1 and increased MVD may indicate a poor prognosis for certain patients.

Expressions of nuclear factor kappaB, inducible nitric oxide synthase, and vascular endothelial growth factor in adenoid cystic carcinoma of salivary glands: correlations with the angiogenesis and clinical outcome

OBJECTIVE

To evaluate the expressions of nuclear factor kappaB (NF-kappaB p65), inducible nitric oxide synthase enzyme (iNOS), and vascular endothelial growth factor (VEGF) in relation to angiogenesis (microvessel density, MVD) and clinical outcomes in adenoid cystic carcinoma (ACC) of salivary glands.

METHODS

Immunohistochemical staining was used to quantify the protein expression levels of NF-kappaB p65, iNOS, and VEGF in 80 surgically resected ACCs and 20 normal salivary tissues. In all cases of ACCs, MVD was evaluated by counting CD34-reactive endothelial cells or endothelial cell clusters.

RESULTS

The nuclear localization of NF-kappaB p65 was only detected in ACC cells. Both iNOS and VEGF staining activities in ACCs were more significant than those in normal gland tissues (P < 0.01). MVD had significant correlations with NF-kappaB p65, iNOS, and VEGF expressions (P < 0.01). In three histologic types of ACCs, the NF-kappaB, iNOS, VEGF expressions, and MVD were significantly higher in solid type than in cribriform and tubular types (P < 0.01). The NF-kappaB, iNOS, VEGF expressions, and MVD were significantly correlated with clinical stage, tumor size, vascular invasion, recurrence, and metastasis (P < 0.05). Multivariate analysis showed NF-kappaB, iNOS and VEGF expression, MVD, solid histotype, and perineural invasion had an independent prognostic effect on overall survival.

CONCLUSION

The expressions of NF-kappaB p65, iNOS, and VEGF were related with MVD. Clinical outcomes raised the possibility that the overexpression of these cytokines might contribute to tumor angiogenesis and have prognostic value in ACCs.

Vascular endothelial growth factor in salivary pleomorphic adenomas: one of the reasons for their poorly vascularized stroma

To better understand the poorly vascularized background of the stroma of pleomorphic adenomas, we attempted to determine the expression of molecules related to blood vessels and hypoxic conditions in pleomorphic adenoma. Surgical specimens and tumor cells in primary culture of salivary pleomorphic adenomas were used for immunohistochemistry for CD31, vascular endothelial growth factor (VEGF) and its receptors Flk-1 and Flt-1, as well as for hypoxia markers, such as hypoxia-inducible factor-1alpha (HIF-1alpha) and lactate dehydrogenase-1 (LDH). At the same time, alternative splicing modes of the VEGF gene and expression levels of the HIF-1alpha gene were analyzed in surgical specimens by means of reverse-transcription polymerase chain reaction (RT-PCR) and direct sequencing of the PCR products. In addition to co-immunolocalization with CD31+ vascular endothelial cells, VEGF and its receptors were demonstrated in normal duct epithelial and myoepithelial cells as well as in tumor cells in ductal structures and in myxochondroid stromata. Immunolocalizations for HIF-1alpha and LDH were confirmed in the VEGF-positive area. Immunofluorescence signals for VEGF and others were confirmed in pleomorphic adenoma cells in culture. RT-PCR results showed that there were at least four splicing modes of the VEGF gene, among which VEGF(121) was most enhanced, and higher HIF-1alpha levels in pleomorphic adenomas. The results suggest that pleomorphic adenoma cells produce VEGF in several functional forms for their own proliferation or differentiation, and that the VEGF expression is controlled by hypoxic circumstances of poorly vascularized pleomorphic adenomas.

Colour Doppler ultrasound in preoperative assessment of the neck vessels in patients with tumours of the oral cavity and the neck region

BACKGROUND

The aim of the study was not only to establish the applicability of color Doppler ultrasound of the neck vessels in patients with tumors of the oral cavity and the neck region but also to check whether the coexistence of sclerotic changes in the carotid arteries is essential in determination of the sequence of surgical procedure.

MATERIAL/METHODS

Color Doppler ultrasound was performed on 110 patients, aged 15 -71 years with tumors of the oral cavity and the neck. The localization, size, echogenicity, as well as the tumor relationship to the surrounding structures and big vessels of the neck region was analyzed.

RESULTS

Compression of the veins was observed in 27 cases, and of the arteries only in 20 cases. Infiltration of the jugular vein was observed in 8 patients, whereas infiltration of the carotid artery were seen only in 6 patients. Severe internal carotid artery stenosis, due to arteriosclerosis, was observed in 10 patients. Three persons were suggested to be operated on, first due to carotid artery stenosis, later on, due to the oral cavity tumor.

CONCLUSIONS

It was found that color Doppler ultrasound is useful in deciding upon the method of treatment, while the examination of the neck vessels is helpful in establishing the sequence of surgical procedures in patients with tumors and coexisting arteriosclerosis.

[Microvessel density and expression of vascular endothelial growth factor in adenoid cystic carcinoma of salivary gland]

OBJECTIVE

To discern whether the microvessel density (MVD) and the expression of vascular endothelial growth factor (VEGF) could be prognostic indicators for the metastasis and survival of patients with SACC after radical surgery.

METHODS

After the follow-up of 31 primary patients with SACC treated with radical surgeries for at least 60 months, the paraffin-bedded sections of the those patients were stained immunohistochemically with anti-CD34-McAb and anti-VEGF-McAb, respectively. Subsequently, two pathologists double-blindly evaluated the sections stained with anti-CD34-McAb to determine the MVD values individually, as well as, measured the sections stained with the ani-VEGF-McAb to determine the OD values. Consequently the data were analyzed with the statistic software package detailed.

RESULTS

The univariate statistical analysis showed that the pathological types of SACC, the TNM stages, MVD and OD values were all statistically significant variables for the survival of the patients with SACC (P = 0.047, 0.000, 0.000, 0.024). Furthermore, among those reliable variables, only MVD was more significant in the Cox proportional hazard model for the multivariate analyses (P = 0.000). The MVD values were statistically significantly higher, in the group with either death, or metastasis, or tumor-relapse, or worse pathological types, or advanced TNM stages, than their counterparts respectively(P = 0.029, 0.045, 0.019, 0.031, 0.00). On the other hand, the OD values were also statistically significantly higher, in the group with either death, or worse pathological types, or advanced TNM stages, than their counterparts respectively(P = 0.037, 0.013, 0.014). The results of Fisher exact test showed that the incidence of distant metastasis differed statistically significantly between the subgroups divided with the median of the MVD values (P = 0.032). The stepwise linear regression equation showed that the MVD value correlated positively with the OD value (P = 0.029).

CONCLUSIONS

The MVD value and the expression level of VEGF all have statistically significant correlations with the survival of the patients with SACC, moreover, the MVD value is more significant as a prognostic indicator. The MVD value could also be a prognostic indicator for the incidence of the distant metastasis of patients with SACC. The over-expression of VEGF in SACC might contribute to the MVD values increasing.

Three-dimensional angioarchitecture in transplantable rat fibrosarcomas

Three-dimensional angioarchitecture in a transplantable fibrosarcoma (SS) in F344 rats was investigated by scanning electron microscopy (SEM) of vascular corrosion casts. Tumours were produced in syngeneic rats by implantation of a tumour fragment from another SS tumour. Viable SS tumours, observed up to post-implantation (PI) week 5, showed a high degree of vascularization, consisting of arterioles and veins, and intertwining capillaries branching from such vessels. The capillaries showed numerous finger-like outgrowths, indicating active sprouting of endothelial cells and contributing to tumour growth. In contrast, SS tumours in rats given a single dose (4 mg/kg/bodyweight) of cisplatin at PI week 1 were reduced in volume, lacking in capillary outgrowths, and of low vascular density. Necrotic areas in SS tumours were surrounded by capillaries with sharp tips and wrinkled surfaces. Thus, the findings indicated differences in three-dimensional angioarchitecture between vigorously developing tumours and (1) tumours degenerating as the result of treatment with an anti-cancer drug, or (2) necrotic tumour tissues. SEM of vascular corrosion casts may prove useful for the evaluation of neovascularization in mesenchymal tumours.

Abnormal venous structures in salivary gland tumors: vasculature characteristics of pleomorphic adenoma

To clarify the diagnostic significance of abnormal venous structures present in salivary gland tumors, we examined 21 pleomorphic adenomas, 14 Warthin tumors, 1 oncocytic adenoma, 3 myoepitheliomas, 7 basal cell adenomas, 5 mucoepidermoid carcinomas, and 6 adenoid cystic carcinomas. Verhoeffvan Gieson staining was carried out and the morphology of the veins within the tumors was observed microscopically. Branching veins, thickened intima of the veins, discontinuous elastic membrane and multilayered elastic membrane were seen in 71.4%, 76.2%, 47.6% and 85.7% of pleomorphic adenomas, respectively, and were abundant and easily found in most cases. The abnormal venous structures were also found in other salivary gland tumors examined, but they were few in number and lacked variety. Elastic fibers extending radially into the surrounding stroma were seen in 66.7% of pleomorphic adenomas, and were not seen in other salivary gland tumors. Our results showed that a variety of abnormal venous structures are more abundant and more easily found in pleomorphic adenoma compared with other salivary gland tumors, and, in particular, that perivascular radiating elastic fibers are characteristic of pleomorphic adenoma. We emphasize that the presence of perivascular radiating elastic fibers may be helpful in diagnosing pleomorphic adenoma in small biopsy specimens.

[Clinico-pathological significance of microvessel density and vascular endothelial growth factor expression in adenoid cystic carcinoma of salivary glands]

OBJECTIVE

To evaluate the clinical significance of microvessel density(MVD) and vascular endothelial growth factor(VEGF) expression in adenoid cystic carcinoma of salivary glands.

METHODS

Immunohistochemical staining(SP) was used to quantify MVD and VEGF expression in specimens from 55 patients with adenoid cystic carcinoma of salivary glands. SPSS statistical software was used.

RESULTS

High VEGF expression was correlated with tumor site and stage (P = 0.0398, P = 0.0175), but not with local recurrence, distant metastasis, regional lymph node metastasis, histological classification and survival rate. A significant correlation was not noted between MVD and the above variables. The mean MVD in cases of high VEGF expression was significantly higher than those in cases of low VEGF expression (P = 0.0202).

CONCLUSIONS

In adenoid cystic carcinoma of salivary glands, MVD and VEGF may be served as a prognostic factor which needs further study, but there is a significant positive correlation between MVD and VEGF expression.

Hypoxia-induced angiogenesis of cultured human salivary gland carcinoma cells enhances vascular endothelial growth factor production and basic fibroblast growth factor release

The angiogenic activity of two human salivary gland tumor cell lines, ACCS from adenoid cystic carcinoma and IT-2 from mucoepidermoid carcinoma, was examined by stimulating tube formation by bovine capillary endothelial cells (BCE). ACCS and IT-2 were cultured in 20 or 3% oxygen, representing normoxic and hypoxic conditions, respectively, and conditioned medium (CM) was obtained from each culture. The BCE tubes stimulated by hypoxic CM were 1.59 (ACCS) and 1.42 (IT-2) times longer than those stimulated by normoxic CM. The tube-forming activity of CM was inhibited by preincubation with either anti-vascular endothelial growth factor (VEGF) IgG or anti-basic fibroblast growth factor (bFGF) IgG, suggesting that both VEGF and bFGF with angiogenic activity were present in the CM. This was confirmed by ELISA, which also demonstrated increased concentrations of both proteins in the hypoxic CM. Northern blot analysis showed an increased VEGF mRNA level in both carcinoma cells with hypoxia, while hypoxia did not affect the bFGF mRNA level in either cell line. The results suggest that both VEGF and bFGF are major angiogenesis factors in salivary gland tumors, and hypoxia-induced angiogenesis results from upregulation of VEGF and increased release of bFGF.

Salivary carcinoma in HER-2/neu transgenic male mice: an angiogenic switch is not required for tumor onset and progression

Morphologic examinations of salivary gland neoplasias arising in male BALB/c (H-2d) mice carrying the activated HER-2/neu (BALB-NeuT) indicate that expression of the oncogene product in the ductal-acinar structures results in a very human-like acinic cell adenocarcinoma with a smoldering course and infrequent metastatization. Typical and then atypical hyperplasia of ducts and acini preceded the rise of salivary tumors that originated from the confluence of multiple ductal hyperplastic foci, while hyperplastic acini behaved as an abortive preneoplastic lesion. The vascular network in normal, hyperplastic and neoplastic salivary tissue was analysed to see whether activation of the angiogenic process is essential in salivary gland carcinogenesis. Immunostaining with anti-endothelial cells (anti-CD31), anti-beta3 integrin and anti-laminin antibodies revealed that microvessel density was significantly higher in normal and hyperplastic than in neoplastic tissue, in which no signs of new vessel sprouting were found. Assessment of angiogenic factor expression indicates a low presence of VEGF in normal, hyperplastic and neoplastic epithelium, while bFGF was preferentially produced but not exported by neoplastic cells and remained in a cell-associated form. Our data suggest that normal salivary gland vascularization is able to support tumor onset and development with no need for an angiogenic switch.

The role of colour flow Doppler in the investigation of the salivary gland tumour

AIMS

Ultrasound is a highly effective imaging technique to determine salivary gland tumours and may help to identify many benign lesions. The aim of this study is to evaluate whether colour Doppler is able to further differentiate the malignant tumour.

METHODS

Fifty-six patients with salivary gland lesions were prospectively assessed using ultrasound imaging with colour flow and power Doppler. The peak systolic velocity (PSV) was measured and the pulsatility index (PI) and resistive index (RI) calculations were performed on the pulsed wave traces. The real time ultrasound morphology and the Doppler information were correlated with the histology.

RESULTS

In 18 of the 56 patients, no internal colour flow or power Doppler changes could be detected. The real time ultrasound morphology diagnosed benign disease with sensitivity of 89.7% with specificity of 57.1%. The positive predictive value was 93.6%. There were no significant differences in the colour Doppler appearances in terms of vessel type or intratumour distribution which could separate benign from malignant conditions. However, there was statistical discrimination for PI and RI values (P = 0.0006, P = 0.0002, respectively). No malignant lesions were seen when the PI was less than 1.8 and RI was less than 0.8. The PSV was elevated in several cases (> 50 cm per s) but there was no statistical correlation with malignancy.

CONCLUSION

The risk of malignancy increases by a third when the colour Doppler demonstrates increased intratumour vascular resistance (RI > 0.8 and PI > 1.8), with positive predictive value of 97.3% (sensitivity 75.5%, specificity 85.7%).Bradley, M. J. (2000). Clinical Radiology55, 759-762.

Intravascular tumour in intra-oral pleomorphic adenomas: a diagnostic and therapeutic dilemma

AIMS

Intravascular tumour has been described very rarely in pleomorphic adenomas. The aim of this study was to establish the frequency of intravascular tumour in pleomorphic adenomas arising in minor salivary glands and to determine the biological significance of this phenomenon.

METHODS AND RESULTS

Representative sections of 67 widely excised pleomorphic adenomas were examined for the presence of intravascular tumour. Sixty-two cases were derived from the palate while the remaining five were from the cheeks and lips. In instances where intravascular tumour was identified, multiple serial sections were assessed and immunohistochemical stains were performed. None of these cases showed cytological evidence of malignancy. Solid cords of intravascular tumour were present in six palatal tumours (8.9%) and consisted of plasmacytoid myoepithelial cells permeating muscular walled blood vessels and capillaries both within the tumour and capsule. Immunoperoxidase staining confirmed that the intravascular cells were phenotypically identical to those of the tumour being S100- and smooth muscle actin (SMA) positive. There is some evidence that this phenomenon represents true vascular invasion although artefactual spillage cannot be excluded.

CONCLUSIONS

Although the biological significance of intravascular tumour in pleomorphic adenomas of minor salivary glands remains unknown, the occurrence of metastatic disease has not been demonstrated nor have aggressive behaviour or recurrences.

Expression of p53 oncoprotein increases intratumoral microvessel formation in human salivary gland carcinomas

P53 protein and vascular endothelial growth factor (VEGF) expression, and mean intratumoral microvessel density (IMVD) were studied by immunohistochemistry in 31 salivary gland carcinomas, consisting of 11 adenoid cystic carcinomas (AdCCs), 10 mucoepidermoid carcinomas (MECs), 7 acinic cell carcinomas (AcCCs), and 3 squamous cell carcinomas (SCCs). Cases with p53 protein in more than 20% of tumor cells were detected in one AdCC, four MECs, one AcCC, and two SCCs. Both frequency of p53 and VEGF expression, and mean IMVD, were higher in the MECs and SCCs than in the AdCCs and AcCCs. Similarly, both VEGF expression and mean IMVD were significantly higher (P<0.05) in the eight p53-positive tumors than in the 23 negative tumors. Six cases with survival periods less than 5 years showed significantly higher frequency of p53 and VEGF expression and of mean IMVD than those with longer survival periods. These results indicate that p53 expression might partly correlate with VEGF expression and mean IMVD, and be a factor in the survival of patients with salivary gland carcinomas.

[The application of color Doppler ultrasound technique in diagnosing the lumps of salivary gland]

OBJECTIVE

To evaluate the value of color doppler ultrasound technique in diagnosing the lumps of salivary gland.

METHODS

233 cases of salivary gland lumps were examined with color doppler high frequency ultrusound technique. Among them were, 189 cases benign and the others malignant.

RESULTS

Color doppler ultrasound technique could not only show the morphology, structure, sizc, location and adjoining relationship, but also indicate the pathological classification according to the blood supply. The total coincident rate of this ultrasound diagnosis to the pathological one was 89.3%.

CONCLUSION

Color doppler ultrasound technique is a simple and harmless diagnosing method and could preoperatively give a reliable information to the decision of surgical plan.

Primary pleomorphic adenoma in posterior cranial fossa

A 35-year-old woman had an intradural tumor in the posterior fossa adjacent to the posterior wall of the left pyramidal bone, which was totally removed and histologically diagnosed as a pleomorphic adenoma. Follow-up examination for 2 years showed no recurrence of the tumor. There was no primary lesion in any other gland of the body, and therefore there is no alternative but to conclude a "migration" of some gland cells. The pathogenesis of this tumor remains unclassified.

True malignant mixed tumor (carcinosarcoma) of tonsillar minor salivary gland origin: diagnostic imaging and endovascular therapeutic embolization

We report a case of carcinosarcoma of the minor salivary glands of the left palatine tonsil, an especially rare location. Imaging characteristics assessed at CT, MR imaging, and angiography are presented. In addition, we describe our experience with preoperative therapeutic endovascular embolization of this hypervascular tumor.

The value of magnetic resonance imaging in the differential diagnosis of parapharyngeal space tumours

Between 1987 and 1993 14 patients with a parapharyngeal space tumour were imaged by magnetic resonance imaging (MRI). The vagal body tumours, presenting in the poststyloid compartment, all showed flow voids with anterior and medial displacement of the internal carotid artery. None of the salivary gland tumours, all presenting in the prestyloid compartment with posterior displacement of the internal carotid artery, showed flow voids. MRI is superior compared with other modalities in evaluating the differential diagnosis, especially regarding vascular vs non-vascular tumours. It should encompass T1 SE images to assess the presence or absence of flow voids. In vascular tumours angiography must be used to assess feeding vessels, multiplicity, and sides involved. T1 GE images are useful as they allow superior identification of the internal carotid artery and its relation with the tumour accordingly. In addition to T1 SE images, T2 SE images may help in the evaluation of the differential diagnosis. In all non-vascular tumours aspiration cytology is required to differentiate between benign and malignant disease.

Salivary gland tumours: is colour Doppler imaging of added value in their preoperative assessment?

Using a Toshiba SSA-270A Colour Duplex Scanner, 15 patients with suspected parotid and submandibular gland tumours had preoperative duplex scanning done. Peak systolic doppler shifts (fmax) were recorded and their vascularity was also subjectively scored. There were no arteries identified within the substance of contralateral normal glands. All recordings were analysed retrospectively and an independent histological assessment of tumours was made. Pleomorphic adenomas (n = 9) had a median peak systolic frequency (fmax) of 0.8 kHz, while adenolymphomas (n = 4) had a fmax of 1.65 and the two malignant tumours had fmax of 4.5 (P = 0.007 Kruskal-Wallis test). There appears to be a strong correlation between the fmax and the subjective vascular score (Corr 0.92). Colour duplex scanning is a non-invasive procedure which may be of help in the preoperative assessment of salivary gland tumours.

Histochemical studies of intercellular components of salivary gland tumors with special reference to glycosaminoglycan, laminin and vascular elements

In 41 salivary gland tumors, the characteristics of the intercellular components and vascular endothelial cells were surveyed by immunohistochemical staining for laminin and factor VIII-related antigen (VIII R:Ag), and by mucopolysaccharidase-digestion for glycosaminoglycan (GAG). In myxomatous areas of pleomorphic adenomas, small vessels (diameter 6.5 +/- 0.11 micron) were frequent and found to be negative or weakly positive by VIIIR:Ag staining although endothelial cells were clearly positive for VIIIR:Ag in capsule surrounding the tumor tissues. Alcian blue stainability was diminished by treatment with both Streptomyces hyaluronidase and chondroitinase. By laminin staining, a vascular pattern was clearly detected, but the majority of tumor cells were not stained. In adenomatous areas, the basement membrane-like linear laminin-staining reaction was observed to be weak and inconsistent around some tumor cell nests. However, in adenoid cystic carcinomas, laminin-positivity was much more intense than in other tumors such as pleomorphic adenoma, mucoepidermoid tumor and adenocarcinoma. In cylindromatous areas, the inner luminal surface in the pseudocysts was markedly positive for laminin, and there was weak positivity around tumor cell nests having a trabecular pattern. By immunoelectron microscopy, a juxtacellular network of replicated basal lamina of tumor cells which lined the inner surface of pseudocysts was positive for laminin. Alcian blue-positivity in the pseudocyst was abolished with heparitinase and chondroitinase, but not with hyaluronidase.