The role of lipofilling in reconstructions with dermal regeneration template: clinical and histological assessment.

Skin and soft tissue reconstruction represents one of the most debated issues of plastic surgery. The advent of regenerative medicine has shown new pathways with the use of lipofilling and dermal regeneration templates. The aim of this study was to investigate the histological and clinical modifications occurring after lipofilling in the areas previously reconstructed with Integra® and an autologous thin dermal-epidermal graft. Histological and immunohistochemical analysis were performed on nine patients to compare skin before and after lipofilling. Pre- and post-operative examinations (POSAS, VAS scale) were carried out as well as taking clinical photographs. The authors detected an overall clinical and histological improvement in all cases. Data obtained from POSAS and VAS scale showed a statistically significant (p less than 0.05) improvement concerning all variables investigated before surgery. The biopsies revealed qualitative modifications with hematoxylin-eosin and Masson trichrome stain. Immunohistochemistry with CD31 antibody also demonstrated quantitative changes with an increased number of vessels. The photographs enabled to compare the clinical situation before and after lipofilling with better aesthetic outcomes. Lipofilling gave good functional and aesthetic results in the areas treated with Integra® and autologous thin dermal-epidermal grafts.

Expression of poly(ADP-ribose) polymerase in bone regeneration.

Poly(ADP-ribose) polymerase (PARP) is a 116kDa enzyme catalysing the synthesis of ADP-ribose polymers from NAD+. PARP is activated in response to DNA strand breaks and plays a critical role in the maintenance of genomic integrity. However, considering its role also in transcription, proliferation as well as apoptosis in biological process, in the present study the role of PARP in bone regeneration was evaluated, in particular in bone cell proliferation and differentiation processes. Thus, formalin fixed paraffin embedded specimens of 10 human bone samples after sinus lift were collected and investigated by immunohistochemistry using a mouse monoclonal anti-human PARP antibody. PARP was expressed in cells with morphological features of osteoblasts in the areas of new bone formation at the junction between mineralized and unmineralized tissue, between osteoid tissue and bone. Few osteoclasts were observed and showed only focal nuclear expression of PARP, while osteocytes showed no positivity for PARP. Our data showed an overall involvement of PARP enzyme in human bone tissues, in particular during bone regeneration process.

Interplay between steroid receptors and neoplastic progression in sarcoma tumors.

Steroid hormones are expressed at low levels in mesenchymal cells and are highly expressed in soft tissue sarcoma. In human soft tissue fibrosarcoma cell line (HT-1080), the epidermal growth factor (EGF) stimulates the express of matrix metal (MMPs) expression through a Src-dependent mechanism. In human fibrosarcomas, increased expression of MMPs correlates with the metastatic progression. Our recent data in human breast cancer cell line MCF-7, demonstrates that EGF stimulates estradiol receptor (ER) phosphorylation on tyrosine at position 537 thereby promoting the association of a complex among EGF receptor (EGFR), androgen receptor (AR), ER, and Src that activates EGF-dependent signaling pathway. In the present study, we demonstrate that, in HT-1080 cells, the Src kinase activity is involved in EGFR phosphorylation and this activity is regulated by an interplay between Src, steroid receptors, and EGFR. In these cells, estradiol (E(2) )/ER and synthetic androgen (R1881)/AR trans-activate EGFR leading to the downstream signaling and to ERK activation. Indeed, the association between ER/AR and EGFR enhances metastatic progression of fibrosarcoma tumors. A population pilot study performed on 16 patients with soft tissue neoplasias highlights that MMPs expression correlates with progression of anaplastic sarcoma as well as overexpression of EGFR. These findings suggest that there is a crosstalk among AR, ER, and EGFR that lead to src activation also in fibrosarcoma cells.

Aurora B expression as a prognostic indicator and possible therapeutic target in oral squamous cell carcinoma.

The aim of this study is to investigate the expression of the chromosomal passenger protein Aurora B and its activated (phosphorylated) form in a large series of human oral squamous cell cancers (OSCC) and to evaluate its clinical and prognostic significance. Western blotting analysis revealed overexpression of both Aurora B and Thr-232 Phopsho-Aurora B in OSCC lines as compared to normal keratinocytes and bladder cancer cells. Furthermore, protein expression was analysed by immunohistochemistry in 101 OSCC of different site, stage and histological grade and in normal peritumoural areas. The intracellular localization of Aurora B in tumour cells was mainly nuclear, especially in proliferative areas, and significant overexpression was found in tumours in comparison to normal peritumoural areas (P=0.012). Staining results were correlated with clinicopathological parameters and long-term follow-up, and a significant association was found between protein expression and tumour stage (stage II, III and IV vs stage I, P=0.030) and size (<2cm vs >2cm, P=0.010). Cox regression analysis confirmed a poorer disease-free survival in cases with high expression of Aurora B protein. Kaplan-Meier curves showed shorter time to progression in patients with high levels of Aurora B expression (p<0.05). Moreover, the tumoral group with nuclear Aurora B immunolocalization had the worst prognosis (P=0.0364 in disease free survival). Our results suggest that assessing Aurora B expression might help in patients’ risk stratification and serve as a novel therapeutic target in advanced OSCCs.

Double demonstration of oncogenic high risk human papilloma virus DNA and HPV-E7 protein in oral cancers.

Oncogenic HPVs are necessarily involved in cervical cancer but their role in oral carcinogenesis is debated. To detect HPV in oral cancer, 38 cases of formalin fixed-paraffin embedded OSCC were studied by both DNA genotyping (MY09/11 L1 consensus primers in combination with GP5-GP6 primer pair followed by sequencing) and immunohistochemistry (monoclonal Abs against capsid protein and HPV-E7 protein, K1H8 DAKO and clone 8C9 INVITROGEN, respectively). HPV-16 tonsil cancer was used as positive control. The overall prevalence of HPV infection in OSCCs was 10.5%. Amplification of DNA samples showed single HPV DNA infection in 3 cases (HPV16; HPV53; HPV70) and double infection in one case of cheek cancer (HPV31/HPV44). The overall HR-HPV prevalence was 7.5%. E-7 antigen was immunohistochemically detected in all HPV-positive cases. HPV+ OSCC cases showed an overall better outcome than HPV negative oral cancers, as evaluated by Kaplan-Meier curves. HPVs exert their oncogenic role after DNA integration, gene expression of E5, E6 and E7 loci and p53/pRb host proteins suppression. This study showed that HPV-E7 protein inactivating pRb is expressed in oral cancer cells infected by oncogenic HPV other than classical HR-HPV-16/18. Interestingly HPV-70, considered a low risk virus with no definite collocation in oncogenic type category, gives rise to the expression of HPV-E7 protein and inactivate pRb in oral cancer. HPV-70, as proved in current literature, is able to inactivates also p53 protein, promoting cell immortalization. HPV-53, classified as a possible high risk virus, expresses E7 protein in OSCC, contributing to oral carcinogenesis. We have identified among OSCCs, a subgroup characterized by HPV infection (10.5%). Finally, we have proved the oncogenic potential of some HPV virus types, not well known in literature.

Aberrant DNA hypermethylation of hMLH-1 and CDKN2A/p16 genes in benign, premalignant and malignant endometrial lesions.

PURPOSE OF INVESTIGATION: aberrant gene function and transcriptional silencing by CpG island hypermethylation have become a critical component in the initiation and progression of endometrial cancer. The aim of this study was to investigate the methylation status of genes associated with aberrant DNA hypermethylation in benign, premalignant and malignant endometrial lesions. METHODS: using nested methylation-specific PCR, we assessed the methylation of the promoter regions of two genes, hMLH1 and CDKN2A/p16, in tissue samples from endometrial polyps (EP), atypical hyperplasia (AH) and endometrial cancer (EC). RESULTS: the promoter region of at least one of the two genes was aberrantly methylated in EP (hMLH1 42%, CDKN2A/p16 16%), AH (hMLH1 16%, CDKN2A/p16 50%), EC (hMLH1 50%, CDKN2A/p16 75%). Interestingly, hypermethylation of both genes was found with significant increased frequence in AH and EC, but not in benign lesions. CONCLUSIONS: our preliminary findings seem to suggest that the association of the two genes hMLH1 and CDKN2A/p16 may allow a differential diagnosis between benign and premalignant/malignant endometrial lesions; this further supports the hypothesis that methylation of such DNA mismatch repair and tumour-suppressor genes may be associated with endometrial carcinogenesis thus representing a valuable target for selective pharmacologic therapy.

Large oral soft tissue metastasis from anaplastic carcinoma of the lung mimicking a primitive malignancy: case report and brief review of the literature.

Metastatic tumours to the oral region are rare, and those reported in the buccal soft tissues are even less frequent. We describe a case of anaplastic carcinoma of the lung in a 60-year-old man, presenting a huge oral metastasis as the first sign of his primitive lung malignancy. Clinically, the oral lesion mimicked a high-grade primitive carcinoma of the oral cavity. The biopsy established the gingival metastasis from lung cancer which was confirmed by a fine-needle aspiration cytology examination. We report an uncommon case of metastatic lung carcinoma to the gingiva emphasizing the differential diagnosis between primary and metastatic tumours; a short discussion on the pathways of metastatization to oral cavity soft tissues, as well as brief review of the literature are also presented.

Prognostic value of human telomerase reverse transcriptase gene expression in oral carcinogenesis.

Human telomerase reverse transcriptase (hTERT) gene expression in resected specimens of oral squamous cell carcinoma (OSCC) and their surrounding tissue, either apparently normal or clearly histologically dysplastic, was evaluated by both real-time RT-PCR and immunohisto-chemical protein analyses. The expression level of hTERT in oral dysplasia and in OSCC was markedly higher than in normal tissues. The correlation between hTERT expression in OSCC and clinico-pathological parameters or survival of OSCC patients was statistically analyzed. Our study demonstrates that there is no significant relationship between hTERT expression and classical clinico-pathological parameters. Interestingly, survival analysis showed both overexpressing cases and lower survival rate in the early stage of OSCC (p=0.03 for immunohistochemistry; p=0.04 for RT real-time PCR). The histological location of hTERT in these tumors has been discussed in the context of the cancer stem cell theory.

Cyclooxygenase isozymes in oral squamous cell carcinoma:a real-time RT-PCR study with clinic pathological correlations.

COX-2 expression in tumour cells has been associated with carcinogenesis in many human neoplasms, including head and neck cancer, while the COX-1 isoform of the cyclooxygenase enzyme is constitutively expressed in normal tissues. We measured COX-1 and COX-2 m-RNA expression in samples of both oral cancer and matched oral mucosa from 22 patients by RealTime RT-PCR; clinic pathological data (grading, TNM staging, inflammation, follow-up) of all patients were available for statistical evaluation. Most of the tumor samples in our study expressed at least one cyclooxygenase enzyme (COX-1 or COX-2 mRNA) more than their matched normal oral mucosa (p<0.05), with no correlation with the entity of inflammation, and a significant inverse relationship was found between COX-1 and COX-2 in each sample. Higher levels of COX-2 expression were associated with poor disease-free survival (p<0.05), but not with overall survival and higher tumor stage and grade. Our results suggest that COX-1 may play a role in oral carcinogenesis, and could be regarded as a potential therapeutic target by chemo preventive drugs; moreover, COX-2 expression might be addressed as a new prognostic tool in the clinical management of OSCC.

Report of a case of discoid lupus erythematosus localised to the oral cavity: immunofluorescence findings.

Discoid Lupus Erythematosus (DLE) is a chronic disease with a typical cutaneous involvement. This pathology rarely involves mucosa: oral cavity is interested in 20 percent of DLE patients. We describe a case of oral DLE in a 50-year-old woman with an anamnesis for autoimmune disorders. This study shows the helpful role of immunofluorescence in the diagnosis of autoimmune diseases. The first diagnostic step was the clinical observation of the oral mucosa: the lesion area was erythematous, atrophic and hyperkeratotic. The patient then underwent laboratory examination. We utilized human epithelial cells (Hep-2010) for Indirect Immuno-Fluorescence (IIF). Moreover, the biopsy site for Direct Immuno-Fluorescence (DIF) and histopathological analysis was the untreated oral lesion. IIF detected an increase of Anti-Nuclear Antibody (ANA) and positivity for SSA-RO. By DIF, we observed IgG/IgA/fibrinogen along basal layer. Multiple biopsies reported signs of chronic basal damage. Steroid systemic therapy induced a considerable lesion regression. We suggest the use of immunofluorescence with the integration of further data to improve diagnosis of rare diseases and to establish a suitable therapy.

Autophagy analysis in oral carcinogenesis.

OBJECTIVE: The aim of this study was to evaluate the levels of autophagy in oral leukoplakia and squamous cell carcinoma and to correlate with clinical pathological features, as well as, the evolution of these lesions. METHODOLOGY: 7 Normal oral mucosa, 51 oral leukoplakias, and 120 oral squamous cell carcinomas (OSCC) were included in the study. Histological sections of the mucosa and leukoplakias were evaluated throughout their length, while the carcinomas were evaluated using Tissue Microarray. After the immunohistochemical technique, LC3-II positive cells were quantified in the different epithelial layers of the mucosa and leukoplakias and in the microarrays of the squamous cell carcinomas. The correlation between positive cells with the different clinical-pathological variables and with the evolution of the lesions was tested using the t test, ANOVA, and Kaplan-Meier survival analysis. RESULTS: We observed increased levels of autophagy in the oral squamous cell carcinomas (p<0.001) in relation to the other groups, but without any association with poorer evolution or survival of these patients. Among the leukoplakias, we observed a higher percentage of positive cells in the intermediate layer of the dysplastic leukoplakias (p=0.0319) and in the basal layer of lesions with poorer evolution (p=0.0133). CONCLUSION: The levels of autophagy increased during the process of oral carcinogenesis and are correlated with poorer behavior of the leukoplakias.

Tumor infiltrating lymphocytes in uveal melanoma: a link with clinical behavior?

Experimental and clinical evidence indicate that immunological mechanisms might be important in the clinical course of uveal malignant melanoma (UMM). We analyzed the amount and phenotype of tumor infiltrating lymphocytes (TIL) and the expression of the apoptosis-inducing molecule Fas and its ligand, FasL, on tumor cells and TIL in a selected series of UMM with the aim to establish if a correlation between their expression and the clinical behavior of UMM exists. TIL phenotype and Fas/FasL expression were evaluated by immunohistochemistry in 61 cases of formalin-fixed, paraffin-embedded UMM. Results were compared with the follow-up data of patients. Most of the UMM showed a prevalence of CD8+ CD3+ T lymphocytes, or CD4+ and CD8+ cells in equal amounts. UMM showed a variable expression of FasL, ranging from 0 to > 40% of neoplastic cells. Fas was always expressed in TIL, although with a variable extent. A subgroup of UMM showed in TIL a strongly reduced or even absent expression of TCR zeta-chain, involved in activation of T-lymphocytes. This subgroup was characterized by a worse outcome. We hypothesized that an impaired cytotoxic immune response due to the loss of the zeta-chain expression plays a primary role in the biological course of UMM. Our results indicate that the overcoming of the impairment of TCR function may represent a prerequisite for the development of new therapeutic strategies for managing UMM, suggesting that elimination of tumor cells may be possible by activation of cytotoxic cells present within ocular melanomas.

STK11 mutations in Peutz-Jeghers syndrome and sporadic colon cancer.

A potential tumor suppressor gene, STK11 , encoding a serine threonine kinase, has recently been identified on chromosome 19p13. Germ-line mutations of this gene have been found in patients with Peutz-Jeghers syndrome (PJS). To further investigate the relevance of STK11 mutations in PJS, we analyzed its coding sequence in nine patients and identified two deletions and three missense mutations. Because intestinal carcinomas have been observed to develop in association with PJS, we analyzed tumors from 71 patients for allelic deletions (loss of heterozygosity) and STK11 gene mutations, to elucidate the etiological role of STK11 gene in sporadic colorectal cancer. Loss of heterozygosity, evaluated using the microsatellite D19S886, was observed in 10 of 52 informative cases. No somatic mutations were detected except for a missense alteration in one tumor. Our data indicate the heterogeneity of PJS and the infrequent involvement of the STK11 gene in colorectal cancer.

Role of Runx2 phosphorylation in prostate cancer and association with metastatic disease.

The osteogenic transcription factor, Runx2, is abnormally expressed in prostate cancer (PCa) and associated with metastatic disease. During bone development, Runx2 is activated by signals known to be hyperactive in PCa including the RAS/MAP kinase pathway, which phosphorylates Runx2 on multiple serine residues including S301 and S319 (equivalent to S294 and S312 in human Runx2). This study examines the role of these phosphorylation sites in PCa. Runx2 was preferentially expressed in more invasive PCa cell lines (PC3>C4-2B>LNCaP). Furthermore, analysis using a P-S319-Runx2-specific antibody revealed that the ratio of P-S319-Runx2/total Runx2 as well as P-ERK/total ERK was highest in PC3 followed by C4-2B and LNCaP cells. These results were confirmed by immunofluorescence confocal microscopy, which showed a higher percentage of PC3 cells staining positive for P-S319-Runx2 relative to C4-2B and LNCaP cells. Phosphorylated Runx2 had an exclusively nuclear localization. When expressed in prostate cell lines, wild-type Runx2 increased metastasis-associated gene expression, in vitro migratory and invasive activity as well as in vivo growth of tumor cell xenografts. In contrast, S301A/S319A phosphorylation site mutations greatly attenuated these Runx2 responses. Analysis of tissue microarrays from 129 patients revealed strong nuclear staining with the P-S319-Runx2 antibody in primary PCas and metastases. P-S319-Runx2 staining was positively correlated with Gleason score and occurrence of lymph node metastases while little or no Runx2 phosphorylation was seen in normal prostate, benign prostate hyperplasia or prostatitis indicating that Runx2 S319 phosphorylation is closely associated with PCa induction and progression towards an aggressive phenotype. These studies establish the importance of Runx2 phosphorylation in prostate tumor growth and highlight its value as a potential diagnostic marker and therapeutic target.

p63 expression in odontogenic cysts.

A total of 123 cases of odontogenic cysts, distributed as follows: 30 follicular (FC), 35 radicular (RC), 53 keratocysts, 1 glandular odontogenic and 4 calcifying odontogenic cysts, were analysed by immunohistochemistry for expression of p63, a component of p53 protein family. In RCs p63 positivity was not only in basal and parabasal layers but also in the intermediate layer and about 1/3 of cases displayed a percentage of stained cells comprised between 0 and <5%, and about 2/3 between >5% and <50%. In FCs positivity was confined to basal and parabasal layers of the epithelium and in the majority of FCs the stained cells were comprised between 0 and <5%. OKCs displayed the most intense and diffuse p63 labeling. In conclusion, these data suggest that p63 expression may be useful to identify cysts type with more aggressive and invasive phenotype supporting the hypothesis of a suprabasal proliferative compartment in OKCs.

Toll-like receptor 4 expression in the epithelium of inflammatory periapical lesions. An immunohistochemical study.

Toll-like receptors (TLR) are essential for the innate immune response against invading pathogens and have been described in immunocompetent cells of areas affected by periapical disease. Besides initiating the inflammatory response, they also directly regulate epithelial cell proliferation and survival in a variety of settings. This study evaluates the in situ expression of TLR4 in periapical granulomas (PG) and radicular cysts, focusing on the epithelial compartment. Twenty-one periapical cysts (PC) and 10 PG were analyzed; 7 dentigerous non-inflamed follicular cyst (DC) served as control. TLR4 expression was assessed by immunohistochemistry. TLR4 immunoreaction products were detected in the epithelium of all specimens, with a higher percentage of immunostained cells in PG. Although TLR4 overexpression was detected in both PG and PC, there were differences that seemed to be related to the nature of the lesion, since in PG all epithelial cells of strands, islands and trabeculae were strongly immunoreactive for TLR4, whereas in PC only some areas of the basal and suprabasal epithelial layers were immunostained. This staining pattern is consistent with the action of TLR4: in PG it could promote formation of epithelial cell rests of Malassez and in epithelial strands and islands the enhancement of cell survival, proliferation and migration, whereas in PC TLR4 could protect the lining epithelium from extensive apoptosis. These findings go some way towards answering the intriguing question of why many epithelial strands or islands in PG and the lining epithelium of apical cysts regress after non-surgical endodontic therapy, and suggest that TLR4 plays a key role in the pathobiology of the inflammatory process related to periapical disease.

Differential expression of TLR3 and TLR4 in keratocystic odontogenic tumor (KCOT): A comparative immunohistochemical study in primary, recurrent, and nevoid basal cell carcinoma syndrome (NBCCS)--associated lesions.

BACKGROUND: Toll-like receptors (TLRs) play an essential role in the activation of innate immunity and they can promote cancer cell survival and tumor progression. It has been claimed that TLRs can somehow predict the clinical behavior in oral squamous cell carcinoma (OSCCs). AIM: To elucidate the molecular basis underlying keratocystic odontogenic tumor (KOCTs) aggressive behavior and recurrence we carried out this immunohistochemical study on TLR3 and TLR4 expression in sporadic primary KCOTs (sp-KCOTs), sporadic recurrent KCOTs (sp-KCOTs), and NBCCS-associated KCOTs (NBCCS-KCOTs). METHOD: 40 cases of KOCTs removed from 23 men and 17 women were the sample. Paraffin-embedded blocks were processed for immunohistochemistry. Sections were incubated with TLR3 and TLR4 antibodies and immunoreactivity evaluated on a semi-quantitative score. RESULTS: Both TLR3 and TLR4 were expressed in KCOTs epithelium, although with a different extent. TLR3 was not expressed in sp-KCOTs and sr-KCOTs, but it showed a faint staining in NBCCS-KCOTs. On the other hand, both cytoplasmic and nuclear staining for TLR4 was detected in all the 3 types of lesions; however being significantly more expressed in sr-KCOT and NBCCS-KCOTs (p < 0.0001). Our results, demonstrated an association between TLR4, but not TLR3 expression to recurrence behavior of KCOTs. In fact, TLR4 was up-regulated in sr-KCOTs and NBCCS-KCOTs but not in sp-KCOTs. CONCLUSIONS: According these findings it seems conceivable to assume that the up-regulation of TLR4 in some KCOTs can be correlated somehow to their tendency recurrence.

P-cadherin expression predicts clinical outcome in oral squamous cell carcinomas.

P-cadherin, a transmembrane molecule similar to E-cadherin involved in the cell-cell adhesion, and catenins form complexes between its cytoplasmic domain and the cytoskeleton. Five cell lines, 108 specimens of oral squamous cell carcinomas (OSCC), 9 metastasis and 10 of normal oral mucosa were examined to evaluate P-cadherin expression and cellular localization by immunohistochemistry and western-blotting. In normal oral mucosa there was a membranous expression only in basal and parabasal layers. 91 cases (84%) showed membranous/cytoplasmic positivity, whereas 17 cases (16%) were negative. In particular, while well-differentiated carcinomas showed P-cadherin upregulation, the protein was homogeneously hypo- or unexpressed in low-differentiated carcinomas. There was a statistically significant correlation between P-cadherin expression and tumour grading: G3 tumours had a lower score than G1-G2 tumours (P<0.05). When analysed for prognostic significance, patients with no P-cadherin expression (score 0) had poorer overall and diseases-free survival rates than the P-cadherin-expressing group (score 1) (P=0.0463 and P=0.0471, respectively). Western blotting analysis of cell lines and tissue samples confirmed immunohistochemical findings. When cell staining pattern of positive cases was examined, 52 cases showed a prevalent membranous pattern, while 39 had a prevalent cytoplasmic pattern. Cases with prevalent cytoplasmic staining showed high rates of lymph node metastases (P>0.05), and regional relapse (P <0.05) and poorer survival rates than the group with prevalent membranous expression (P<0.0001). An absent P-cadherin expression could constitute a hallmark of aggressive biological behaviour in oral squamous cell carcinoma.

Cyclooxygenase-2 expression in oral squamous cell carcinoma.

Cyclooxygenase (COX), the key enzyme in prostaglandin cascade, is expressed in two isoforms: the constitutive COX-1 and the inducible COX-2. Hyper-expression of COX-2 has been implicated in the pathogenesis of colon-rectal cancer in humans but it appears to play a significant role as a tumour progression factor also in other forms of human cancer, including oral cancer. The aim of this study was to analyze the expression of COX-2, at the protein level, in 45 cases of oral squamous cell carcinoma. Standard immunohistochemical streptavidin-biotin peroxidase analysis was carried out with highly specific antibody against human COX-2 and cell specific markers, in 45 oral squamous cell carcinomas. Our study revealed a moderate to high COX-2 expression in 35 out of the 45 oral squamous cell carcinoma specimens (77.8%). COX-2 expression appeared particularly abundant in the superficial ulcerated layers of relatively well differentiated carcinomas. However, we were unable to assess any statistically significant association between COX-2 hyper-expression and tumor site, tumor grading, tumor size, presence of lymph node metastases, tumor stage and age at onset, respectively. Interestingly, COX-2 expression was detected not only in areas of epithelial dysplasia adjacent to the primary layers (86% of the cases) but also in normal-appearing epithelium at the boundaries of squamous cell carcinoma (77%), indicating a possible involvement in tumour progression by the apparently normal tissue surrounding the lesion. Moreover, intense COX-2 staining was observed in endothelial cells of intra-tumour vessels and extra-tumour vessels adjacent to the tumour nests, in a high proportion of cases (82%). COX-2 positivity was associated with CD34 and VEGF positivity, indicating that these vessels were probably neo-formed ones. From this study as well as from other works, it appears that indeed COX-2 is over-expressed in this important human malignancy. However, further studies are necessary to understand the exact magnitude of this over-expression and, mostly, the possible role of COX-2 in the pathogenesis and progression of oral cancer.

Inflammatory fibroid polyp of the rectum.

A case of inflammatory fibroid polyp of the rectum in an 8 years old boy is reported. This lesion is not infrequently found in the gastro-intestinal tract, is very rare in childhood and has never been reported in the rectum. The pathogenetical hypothesis that fibroid represents a dynamic response to recurrent small injuries with possible different histological patterns is prospected.