Differentiation of squamous cell carcinoma and inverted papilloma using non-invasive MR perfusion imaging.

OBJECTIVES: To investigate the diagnostic value of tumour blood flow (TBF) obtained with pseudocontinuous arterial spin labelling for the differentiation of squamous cell carcinoma (SCC) and inverted papilloma (IP) in the nasal or sinonasal cavity. METHODS: We retrospectively analysed the cases of 33 patients with SCC and 8 patients with IP in the nasal or sinonasal cavity. Pseudocontinuous arterial spin labelling scanning was performed for all patients using a 3.0-T MR unit. Quantitative TBF values were measured by two neuroradiologists by respectively delineating the whole-tumour regions of interest, and the mean of them was determined as TBF value in each patient. Additionally, the presence of imaging findings of convoluted cerebriform pattern (CCP) on MR T2 weighted images was determined in all patients. As a subgroup analysis, patients with IP were divided into aggressive and non-aggressive IPs depending on their progression range. First, an intraclass correlation coefficient (ICC) of TBF values between two neuroradiologists was determined. Next, a statistical comparison of the TBF value by a Mann-Whitney U test between the patients with SCC and IP was performed. Additionally, the comparison by an ANOVA with a post hoc test of Tukey's method among the SCC, non-aggressive IP and aggressive IP groups was also performed. If significance was observed, the diagnostic accuracy to differentiate SCCs from IPs was calculated. Diagnostic accuracy by CCP findings alone and by the combination of CCP findings and TBF were also assessed. RESULTS: The ICC of TBF values between two neuroradiologists was 0.82. The mean TBF values in the patients with SCC, all patients with IP, those with aggressive IP and those with non-aggressive IP were 141.2 ± 33.1, 77.8 ± 31.5, 109.4 ± 16.7 and 58.8 ± 19.9 ml 100 g⁻¹ min⁻¹, respectively. A significant difference was observed between SCC and IP (p < 0.001), SCC and non-aggressive IP (p < 0.01) and non-aggressive IP and aggressive IP (p < 0.01). The diagnostic accuracy values obtained with receiver operating characteristic curve analysis for the differentiation of SCC from IP and for SCC from non-aggressive IP were 0.90 and 0.92, respectively. The diagnostic accuracy was elevated (0.95 from 0.88) by adding the TBF value to CCP findings. CONCLUSIONS: The pseudocontinuous arterial spin labelling technique can be a useful non-invasive diagnostic tool to differentiate SCC from IP in nasal or sinonasal cavity.

Overexpression of angiomotin in sinonasal inverted papilloma.

BACKGROUND: Although inverted papilloma (IP) is one of the most common sinonasal tumors, its etiology and factors associated with tumor progression have not been fully determined. Generally, tumorigenesis or tumor growth requires angiogenesis to feed tumor cells. Angiomotin is a recently discovered protein that regulates migration and tubule formation in endothelial cells. It has been reported that angiomotin affects angiostatin (circulating inhibitor of angiogenesis), resulting in promotion of angiogenesis. Thus, we evaluated the expression and distribution of angiomotin in sinonasal IP, compared to normal control tissue. METHODS: The study included 10 subjects with sinonasal IP and 5 normal controls. Ethmoid sinus mucosa obtained during reduction of blowout fractures was used as a normal control. Reverse transcriptase-polymerase chain reaction (RT-PCR), real-time PCR, immunohistochemistry, and Western blot analysis were used to assess the expression, intensity, and distribution of angiomotin in tissues. RESULTS: Positive bands for angiomotin were seen in all specimens by RT-PCR. The expression level of angiomotin was significantly upregulated in IP tissues versus normal sinus mucosa by real-time PCR. Immunohistochemistry revealed positive reactions on endothelial cells of capillaries and small vessels within the tumor and normal tissues, but the positivity was significantly stronger in IP. Western blot analysis showed that expression levels of angiomotin were increased in IP compared to normal sinus mucosa. CONCLUSION: Angiomotin, a novel protein in angiogenesis, was overexpressed in IP. Although it is not an etiological or initiating factor in tumor development, it seems to be associated with progression and growth of IP via promoting angiogenesis.

The role of tissue factor pathway inhibitor-2 in malignant transformation of sinonasal inverted papilloma.

The aim was to evaluate the potential role of tissue factor pathway inhibitor-2 (TFPI-2) in the process of malignant transformation of sinonasal inverted papilloma (SIP). We evaluated the expression of TFPI-2 in 23 SIP and 8 SIP with squamous cell carcinoma (IPcSCC), compared to 9 normal sinonasal mucosa by means of Western blot and immunohistochemistry staining. In addition, angiogenesis, vascular endothelial growth factor (VEGF) expression and microvessel density marked by CD105 staining were assessed. Correlation of TFPI-2 expression and angiogenesis in the process of malignant transformation of SIP was investigated. Western blot results demonstrated that the protein level of TFPI-2 in IPcSCC was significantly lower than that in the control group (P < 0.01). In addition, significant difference in TFPI-2 protein expression between SIP and IPcSCC was detected (P < 0.01). Higher number of microvessel per unit area (MVNA) was observed in IPcSCC compared to SIP (P < 0.01). Correlational analysis indicated positive correlation of VEGF and MVNA (r = 0.735), inverse correlation of TFPI-2 and MVNA (r = -0.318). However, no significant correlation between TFPI-2 and VEGF was detected. We conclude that TFPI-2 might be a regulatory molecule in the malignant potential of SIP. Down regulation of TFPI-2 is associated with increased MVNA in IPcSCC, which may be involved in the process of malignant transformation of SIP.

[Expression of fascin and correlation with MVD in sinonasal inverted papilloma].

OBJECTIVE: To investigate the expression of Fascin in sinonasal inverted papilloma (SNIP) and the relationship between Fascin expression and microvessel density (MVD). METHOD: The expression of Fascin and CD34 were determined by immunohistochemistry in 30 cases of SNIP, 12 cases of nasal squamous cell carcinoma (NSCC) and 10 cases of normal inferior turbinate (IT) tissues. Meanwhile, CD34, measure of MVD, was counted at the same time. RESULT: Fascin was expressed in 17 of 30 (56.6%) cases of SNIP, 10 of 12 (83.3%) cases of NSCC and 2 of 10 (20.0%) cases of normal IT tissues. Expression of Fascin was significantly increased in SNIP and NSCC compared to normal tissues (P < 0.01). MVD counts was 23.64 +/- 2.74, 45.10 +/- 5.45, 74.76 +/- 7.32, respectively (P < 0.01). There was a positive correlation between the expression of Fascin and MVD counts. CONCLUSION: The high expression of Fascin and angiogenesis are significantly associated with biological behaviour of SNIP. Fascin may play an important role in the pathogenesis of SNIP and NSCC and synergic role with angiogenesis in progression of SNIP.