Cassiano Francisco Weege Nonaka

Immunohistochemical expression of MMPs 1, 7, and 26 in syndrome and nonsyndrome odontogenic keratocysts

OBJECTIVE The objective of this study was to analyze the expression of matrix metalloproteinases (MMPs) 1, 7, and 26 in odontogenic keratocysts (OKCs) associated with Gorlin syndrome (SOKCs) and nonsyndrome OKCs (NSOKCs). STUDY DESIGN Twenty-one SOKCs and 20 NSOKCs were evaluated for epithelial expression of MMP-1, MMP-7, and MMP-26 and for mesenchymal expression of MMP-1 by immunohistochemistry. RESULTS Strong epithelial positivity to MMP-1 was observed in 76% of SOKCs and in 15% of NSOKCs (P < .05). Strong mesenchymal immunoreactivity to MMP-1 was observed in 38% of SOKCs and in 20% of NSOKCs (P > .05). Epithelial immunoreactivity to MMP-7 was strongly positive in 67% of SOKCs and in 40% of NSOKCs (P > .05). For MMP-26, strong positivity was found in 62% of SOKCs, in contrast to 35% of NSOKCs (P > .05). CONCLUSION MMPs-1, -7 and -26 may play important roles in the biology of OKCs. Furthermore, the presence of these proteases at higher levels in SOKCs may help to explain increased OKC aggressiveness associated with nevoid basal cell carcinoma syndrome.

Immunoexpression of vascular endothelial growth factor in periapical granulomas, radicular cysts, and residual radicular cysts

OBJECTIVE Our aim was to assess and compare the immunoexpression of vascular endothelial growth factor (VEGF) in periapical granulomas (PGs), radicular cysts (RCs), and residual radicular cysts (RRCs), relating it to the angiogenic index and the intensity of the inflammatory infiltrate. STUDY DESIGN Twenty PGs, 20 RCs, and 10 RRCs were evaluated by immunohistochemistry using anti-VEGF antibody. Angiogenic index was determined by microvessel count (MVC) using anti-von Willebrand factor antibody. RESULTS The PGs and RCs showed higher expression of VEGF than the RRCs. Lesions presenting few inflammatory infiltrate revealed the lowest immunoexpression of VEGF (P < .05). Irrespective of the intensity of the inflammatory infiltrate, most of the RCs and RRCs showed moderate to strong epithelial expression of VEGF. Lesions showing dense inflammatory infiltrate presented higher MVC indices (P < .05). VEGF expression and MVC did not reveal a significant correlation (P > .05). CONCLUSIONS VEGF is present in periapical inflammatory lesions but at a lower level in RRCs. The expression of this proangiogenic factor is closely related to the intensity of the inflammatory infiltrate in these lesions.

Frequency of oral mucositis and microbiological analysis in children with acute lymphoblastic leukemia treated with 0.12% chlorhexidine gluconate

In view of the morbidity potential of oral complications in patients with leukemia, this study evaluated the clinical and microbiological alterations that occur in the oral mucosa of children with acute lymphoblastic leukemia (ALL) undergoing antineoplastic chemotherapy and prophylactic administration of 0.12% chlorhexidine gluconate. The sample consisted of 17 children aged 2 to 12 years that underwent clinical examination of the oral mucosa for the detection of oral lesions. In addition, biological material was collected from labial and buccal mucosa for microbiological analysis. Oral mucositis was observed in only 5 (29.4%) patients. Microbiological analysis revealed a reduced number of potentially pathogenic microorganisms, such as coagulase-negative staphylococci (47%), Candida albicans (35.3%), Klebsiella pneumoniae (5.9%), enteropathogenic Escherichia coli (5.9%), and Stenotrophomonas maltophilia (5.9%). Patients with oral mucositis showed a higher frequency of coagulase-negative staphylococci (80%) when compared with patients with normal oral mucosa (33.3%). In conclusion, the results of the present study suggest that the prophylactic use of 0.12% chlorhexidine gluconate reduces the frequency of oral mucositis and oral pathogens in children with ALL. In addition, the present findings suggest a possible relationship between coagulase-negative staphylococci and the development of oral mucositis.

Immunohistochemical expression of mast cell tryptase in giant cell fibroma and inflammatory fibrous hyperplasia of the oral mucosa

This study analysed the immunohistochemical expression of mast cell tryptase in giant cell fibromas (GCFs). In addition, the possible interaction of mast cells with stellate giant cells, as well as their role in fibrosis and tumour progression, was investigated. For this purpose, the results were compared with cases of inflammatory fibrous hyperplasia (IFH) and normal oral mucosa. Thirty cases of GCF, 30 cases of IFH and 10 normal mucosa specimens used as control were selected. Immunoreactivity of mast cells to the anti-tryptase antibody was analysed quantitatively in the lining epithelium and in connective tissue. In the epithelial component (p=0.250) and connective tissue (p=0.001), the largest mean number of mast cells was observed in IFHs and the smallest mean number in GCFs. In connective tissue, the mean percentage of degranulated mast cells was higher in GCFs than in IFHs and normal mucosa specimens (p<0.001). Analysis of the percentage of degranulated mast cells in areas of fibrosis and at the periphery of blood vessels also showed a larger mean number in GCFs compared to IFHs and normal mucosa specimens (p<0.001). The percent interaction between mast cells and stellate giant cells in GCFs was 59.62%. In conclusion, although mast cells were less numerous in GCFs, the cells exhibited a significant interaction with stellate giant cells present in these tumours. In addition, the results suggest the involvement of mast cells in the induction of fibrosis and modulation of endothelial cell function in GCFs.

Immunoexpression of cyclooxygenase-2 and p53 in oral squamous cell carcinoma

PURPOSE Cyclooxygenase-2 (COX-2) is an induced proinflammatory enzyme involved in various steps of carcinogenesis such as cell proliferation, reduction in apoptosis rates, and promotion of tumor angiogenesis. Mutation or inactivation of the tumor suppressor gene p53 is frequently observed in malignant neoplasms and is known to be involved in the early stages of carcinogenesis. Recent studies reveal a possible correlation between COX-2 and p53 expression in several malignant neoplasms. The present study analyzed the correlation between the expression of COX-2 and p53 in oral squamous cell carcinoma (OSCC) and evaluated the differences in the expression of these 2 proteins according to the histologic grade of malignancy of the tumor. MATERIALS AND METHODS Thirty-four cases of OSCC were graded according to the histologic grading system proposed by Bryne [Oral Dis 4(2) (1998) 70-77]. Immunoexpression of COX-2 and p53 was analyzed by counting 1000 neoplastic cells in 5 different fields at the deep invasive front of the tumor under a light microscope. On the basis of the number of immunopositive cells, the labeling index expressed as the percentage of positively stained cells was established for each marker. RESULTS Increased COX-2 expression in most specimens was observed, although no significant correlation was observed between COX-2 and p53 labeling indices (P > .05). Moreover, there were no significant differences in the expression of these proteins between high- and low-grade tumors (P > .05). CONCLUSION The increased expression of COX-2 in OSCC suggests a role for this protein in the pathogenesis and progression of oral cancer.

Adenomatoid odontogenic tumour associated with dentigerous cyst - unusual case report

The adenomatoid odontogenic tumor is a relatively uncommon lesion which mainly affects females in their second decade of life, exhibiting predilection for the anterior region of the maxilla. The lesion is usually associated with the crown of an enclosed tooth, most commonly the maxillary canine. In this paper we present a case of adenomatoid odontogenic tumor associated with a dentigerous cyst affecting the left maxillary region in a 13-year-old female. The authors also discuss clinical, radiographic, histopathologic and therapeutic features of the case.

Nonodontogenic cysts of the oral and maxillofacial region: demographic profile in a Brazilian population over a 40-year period

The aim of the study was to determine the distribution of histologically diagnosed nonodontogenic cysts (nOCs) over a 40-year period in a Brazilian population. Biopsy records from patients with nOC from the files of the Oral Pathology Service during the period of 1970–2009 were evaluated. Among 10,311 oral biopsies, 58 met the criteria of nOCs. The most frequent nOCs were nasopalatine duct cysts (32.8%), followed by epidermoid cysts (20.7%) and oral lymphoepithelial cysts (17.2%). Nasopalatine duct cysts showed predominance among females (68.4%). Epidermoid cysts were most commonly found in the floor of the mouth (36.4%), tongue (27.3%), and buccal mucosa (27.3%). Oral lymphoepithelial cysts exhibited female prevalence (80.0%) and were commonly located in the tongue (44.4%). The frequency of nOCs found in the population studied here is slightly different from those reported in other case series. Nasopalatine duct cysts, epidermoid cysts, and oral lymphoepithelial cysts were the most common nOCs found, accounting for 70.7% of all nOCs.

Role of inflammation in oral carcinogenesis (Part II): CD8, FOXP3, TNF-α, TGF-β and NF-κB expression

Due to the frequent presence of inflammation in cases of carcinoma and its use as a parameter for the assessment of tumor aggressiveness, the role of inflammation in oral carcinogenesis was investigated. This was performed by evaluating the expression of cellular markers, cytokines and nuclear transcription factors that identify the cells that participate in the antitumor defense in cases of oral epithelial dysplasia (OED) and oral squamous cell carcinoma (OSCC). A semi-quantitative immunohistochemical analysis was performed for the transcription factors cluster of differentiation 8 (CD8), forkhead box P3 (FOXP3), transforming growth factor (TGF)-β, tumor necrosis factor (TNF)-α and nuclear factor κ-light chain enhancer of activated B-cells (NF-κB), in cases of OED and OSCC. CD8, TGF-β, TNF-α and NF-κB participated in the processes of tumor transformation and progression. The presence of inflammatory infiltrate in cases of OED favors the transformation and invasion process when stromal TNF-α and NF-kB are overexpressed, as NF-kB activated by TNF-α during inflammation predisposes the lesion to transformation, functioning as a link between inflammation and cancer. The control of these inflammatory mediators may prevent malignant transformation in the oral cavity.

Sialolipoma of minor salivary glands

Sialolipoma is a recently described histologic variant of lipoma and is characterized by well-demarcated proliferation of mature adipocytes with secondary entrapment of salivary gland elements. These tumors have been observed in both the major and minor salivary glands, with more than 20 cases being reported in the English literature. In general, the clinical presentation of sialolipomas of the minor salivary glands suggests a diagnostic hypothesis of salivary gland lesions, commonly neoplasms. In the major salivary glands, the clinical features suggest either a salivary gland neoplasm or a lipoma. Surgical excision is the treatment of choice for sialolipomas, with no reports of recurrence or malignant transformation. The present article reports 4 additional cases of sialolipoma, all of them affecting the minor salivary glands, and reviews the literature regarding clinicopathologic aspects, differential diagnosis, and therapeutic management of this recently recognized histologic variant of lipoma.

Immunohistochemical analysis of bone resorption regulators (RANKL and OPG), angiogenic index, and myofibroblasts in syndrome and non-syndrome odontogenic keratocysts

OBJECTIVE The aim of this study was to immunohistochemically analyse bone resorption regulators (receptor activator of nuclear factor kappa B ligand [RANKL] and osteoprotegerin [OPG]), angiogenic index, and myofibroblasts in Gorlin syndrome-related odontogenic keratocysts (SOKCs) and non-syndrome odontogenic keratocysts (NSOKCs). STUDY DESIGN Twenty-two SOKCs, 22 primary NSOKCs, and eight recurrent NSOKCs were evaluated by immunohistochemistry using anti-RANKL and anti-OPG antibodies. The angiogenic index was determined by microvessel count (MVC) using anti-CD34 antibody. Anti-α-smooth muscle actin (α-SMA) antibody was used for the identification of myofibroblasts. RESULTS Analysis of the expression of RANKL and OPG in the epithelial lining and fibrous capsule did not reveal significant differences between groups (P>0.05). In the epithelial lining, the RANKL/OPG ratio was RANKL0.05). In the fibrous capsule, the ratio was RANKL=OPG in most primary (81.8%) and recurrent NSOKCs (75.0%) and in most SOKCs (45.5%) (P>0.05). No significant differences in the angiogenic index or number of myofibroblasts were observed between primary NSOKCs, recurrent NSOKCs, and SOKCs (P>0.05). CONCLUSIONS The present results suggest that differences in the biological behaviour of SOKCs and NSOKCs may not be related to the expression of RANKL and OPG, to the RANKL/OPG ratio, to the angiogenic index, or to the number of myofibroblasts in these lesions.