Eduardo Rodrigues Fregnani

Presence of Myofibroblasts and Expression of Matrix Metalloproteinase-2 (MMP-2) in Ameloblastomas Correlate with Rupture of the Osseous Cortical

Myofibroblasts are frequent in the stroma of neoplasm and by the expression of proteinases they can influence tumor infiltration and progression. In the present study, presence of myofibroblasts and expression of matrix metalloproteinase-2 (MMP-2) and urokinase plasminogen activator (uPA) were examined in intra-osseous solid multicystic ameloblastomas to determine their roles in the clinicopathological features of the tumors. Fifty seven ameloblastomas were analyzed immunohistochemically with antibodies against the isoform α of the smooth muscle actin (α-SMA), a specific marker of myofibroblasts, MMP-2 and uPA. Myofibroblasts were found in the stroma, in close contact with neoplastic cell islands, of ~58% (n = 33) of the ameloblastomas. MMP-2 and uPA were found in the cytoplasm of both neoplastic and stromal cells. A significant correlation between presence of myofibroblasts and MMP-2 expression was observed. Abundant presence of myofibroblast in the stroma of the tumors and expression of MMP-2 in the neoplastic or stromal cells were significantly correlated with rupture of the osseous cortical, which has been considered an important prognostic marker of ameloblastoma aggressiveness. Ours results suggest that abundant presence of myofibroblasts and expression of MMP-2 in solid ameloblastomas may be associated with a more aggressive infiltrative behavior.

Syndecan-1 (CD138) and Ki-67 expression in odontogenic cystic lesions

The aim of this study was to assess the immunohistochemical expression of syndecan-1 (CD138) and Ki-67 in radicular cysts (RC), dentigerous cysts (DC) and keratocystic odontogenic tumors (KOT). Thirty-five RC, 22 DC and 17 KOT were used in the study and immunohistochemical reactions using anti-syndecan-1 and anti-Ki-67 antibodies were performed by the streptavidin-biotin-peroxidase method. Fishers exact test and Spearmans correlation coefficient were used for statistical analysis of data. Among the studied lesions, no differences in the syndecan-1 expression were observed, but the suprabasal expression of Ki-67 was significantly higher in KOT (p<0.0001), when compared with RC and DC. In RC, there was positive correlation between the expression (p=0.02) and intensity (p=0.0001) of syndecan-1 and between the intensity of syndecan-1 and Ki-67 expression (p=0.01). In the KOT, Ki-67 expression in the suprabasal layer correlated positively with the expression (p=0.01) and intensity (p=0.01) of syndecan-1. The expression of syndecan-1 does not seem to be a determinant factor of the distinct histopathological features and biological behavior of the studied lesions. Nevertheless, positive correlation between syndecan-1 and a cell proliferation marker was observed in RC and KOT.

Cytologic Features of Solitary Fibrous Tumor of the Parotid Gland

BACKGROUND Solitary fibrous tumor (SFT) is a rare neoplasm that most commonly involves the pleura but is increasingly recognized at other locations, including lung, liver, thyroid and parotid glands, with only a few reports describing its cytologic features. CASE The fine needle aspiration biopsy (FNAB) features of an SFT located in the left parotid gland of a 34-year-old woman were compared to the histologic and immunohistochemical aspects of the lesion. CONCLUSION This case confirms that SFT has distinct cytomorphologic features and that FNAB can be helpful in its diagnosis.

Presence of Myofibroblasts and Matrix Metalloproteinase 2 in Radicular Cysts, Dentigerous Cysts, and Keratocystic Odontogenic Tumors: A Comparative Immunohistochemical Study

INTRODUCTION The aim of this study was to analyze the presence of myofibroblasts and matrix metalloproteinase 2 (MMP-2) in radicular cysts (RCs), dentigerous cysts (DCs), and keratocystic odontogenic tumors (KOTs). METHODS For the study, 29 RCs, 19 DCs, and 15 KOTs were selected. Immunohistochemical reactions were performed by using anti-MMP-2 and anti-α-smooth muscle actin (SMA) antibodies. For the analysis, 10 high-power fields were observed in each case to determine the percentage of positive cells, which was classified as negative, weak, or strong. RESULTS The presence of myofibroblasts (α-SMA-positive cells) was most common in KOTs (46.67%), followed by DCs (36.84%) and RCs (31.04%); however, it was not statistically significant (P = .8). The stromal MMP-2 expression was positive in all lesions but 1 case of KOT. Most cases of RC and DC presented strong MMP-2 expression in the stroma, whereas half of the KOTs showed similar classification. The MMP-2 expression was commonly found in the epithelial lining of the lesions; it was strong in almost all KOTs. No correlation between epithelial and stromal MMP-2 and α-SMA expressions was observed. CONCLUSIONS Myofibroblasts and MMP-2 are frequent in RCs, DCs, and KOTs and eventually can contribute to bone resorption, favoring the progression and growth of these lesions.

BRAF-V600E expression correlates with ameloblastoma aggressiveness

The aim of this study was to investigate whether the expression of BRAF‐V600E determines an aggressive clinical and molecular presentation of ameloblastoma.

Fine Needle Aspiration Biopsy in Central Giant Cell Lesion

Background Fine needle aspiration biopsy (FNAB) is a safe and efficient diagnostic method used in numerous lesions of the head and neck region. However, its use in central giant cell lesion (CGCL) is rarely seen. Cases Three cases of CGCL were initially diagnosed with FNAB, emphasizing the cytologic and immunocytochemical features. Conclusion FNAB, particularly when associated with clinical, radiographic and laboratory examinations, plays an important role in the preliminary diagnosis of CGCL.

Mismatch repair system proteins in oral benign and malignant lesions

Different environmental agents may cause DNA mutations by disrupting its double-strand structure; however, even normal DNA polymerase function may synthesize mismatch nucleotide bases, occasionally demonstrating failure in its proofreading activity. To overcome this issue, mismatch repair (MMR) system, a group of proteins specialized in finding mispairing bases and small loops of insertion or deletion, works to avoid the occurrence of mutations that could ultimately lead to innumerous human diseases. In the last decades, the role of MMR proteins in oral carcinogenesis and in the development of other oral cavity neoplasms has grown, but their importance in the pathogenesis and their prognostic potential for patients affected by oral malignancies, especially oral squamous cell carcinoma (OSCC), remain unclear. Therefore, in this manuscript we aimed to review and critically discuss the currently available data on MMR proteins expression in oral potentially malignant lesions, in OSCC, and in other oral neoplasms to better understand their relevance in these lesions.

Parathyroid hormone/parathyroid hormone-related peptide receptor 1 expression in odontogenic cystic lesions.

AIM To evaluate parathyroid hormone/parathyroid hormone-related peptide receptor 1 (PTHR1) expression in odontogenic cystic lesions and to compare immunoexpression between the lesions. METHODOLOGY Thirty-five radicular cysts, 22 dentigerous cysts and 17 keratocystic odontogenic tumours were evaluated. Immunohistochemical reactions against PHTR1 were carried out in 3-μm histological sections, and the expression and the intensity of PTHR1 expression were evaluated. For statistical analysis, the Fisher exact test was used, with a significance of 5%. RESULTS The intensity of expression in the epithelial lining was significantly weaker in the radicular cyst (P = 0.007). However, in the fibrous capsule, the radicular cyst presented higher positivity for PTHR1 (P = 0.04). CONCLUSIONS The probable co-expression of PTHrP and PTHR1 in odontogenic cystic lesions may eventually have an autocrine and/or paracrine stimulus in the epithelial and mesenchymal cells, inducing proliferation and lesion growth.

Radiation dose distribution in the teeth, maxilla, and mandible of patients with oropharyngeal and nasopharyngeal tumors who were treated with intensity-modulated radiotherapy.

The purpose of this study was to evaluate the distribution of the intensity‐modulated radiotherapy (IMRT) dose delivered to the teeth, maxilla, and mandible.

Cytological features of intraoral tumour

Canalicular adenoma is an uncommon, benign salivary gland tumour, which occurs almost exclusively in the intraoral salivary glands. The upper lip is the most common site, accounting for about 80% of all cases, followed by the buccal mucosa and palate. It is commonly diagnosed in patients after 60 years of age and appears as a painless, slowly growing submucosal mass, smaller than 2 cm in dimension. The overlying mucosa may be normal, erythematous or have a bluish tint, similar to a mucocele. Histologically, a canalicular adenoma is composed of cords of columnar and cuboidal cells with occasionally small cystic spaces in between. Commonly, there is also a connective tissue capsule. Based on ultrastructural and histochemical findings, some authors have suggested that the canalicular adenoma could possibly be of excretory duct origin, although intercalated duct origin has also been mentioned. Only a few detailed studies about the cytopathological features of the canalicular adenoma were previously published in the English-language literature. One study using fine needle aspiration biopsy (FNAB) described canaliculi and papillae lined by a layer of columnar epithelium consisting of columnar cells with round, basal nuclei and clear cytoplasm. Here, we describe in detail the clinical, cytological and histological features of two intraoral canalicular adenomas and emphasize the cytological differential diagnosis. Case reports