Expression of extracellular matrix proteins in adenomatoid odontogenic tumor

Altered expression of extracellular matrix (ECM) components has been reported in several pathologies; however, few ECM proteins have been evaluated in adenomatoid odontogenic tumor (AOT). The aim of this study was to analyze the expression and distribution of the ECM proteoglycans: biglycan and decorin; and glycoproteins: osteonectin, osteopontin, bone sialoprotein and osteocalcin in the AOT. Three-micrometer sections from paraffin-embedded specimens were evaluated employing a streptavidin-biotin immunohistochemical method with the antibodies against the proteins previously cited. Only the osteonectin was expressed in the epithelial cells. The eosinophilic amorphous material and the connective tissue showed expression of all components studied. The calcification foci expressed only osteopontin. In conclusion, the low expression of the components studied in neoplastic epithelial cells suggests that the epithelial cells act probably as stimulators of the expression by the stroma, which in turn can act as agonist or antagonist of the tumor growth. These results suggest that the components studied probably have a key role in the biological behavior of the AOT.

SH3BP2-encoding exons involved in cherubism are not associated with central giant cell granuloma

Central giant cell granuloma (CGCG) is a benign lesion with unpredictable biological behaviour ranging from a slow-growing asymptomatic swelling to an aggressive lesion associated with pain, bone and root resorption and also tooth displacement. The aetiology of the disease is unclear with controversies in the literature on whether it is mainly of reactional, inflammatory, infectious, neoplasic or genetic origin. To test the hypothesis that mutations in the SH3BP2 gene, as the principal cause of cherubism, are also responsible for, or at least associated with, giant cell lesions, 30 patients with CGCG were recruited for this study and subjected to analysis of germ line and/or somatic alterations. In the blood samples of nine patients, one codon alteration in exon 4 was found, but this alteration did not lead to changes at the amino acid level. In conclusion, if a primary genetic defect is the cause for CGCG it is either located in SH3BP2 gene exons not yet related to cherubism or in a different gene.

Intralesional injection of triamcinolone hexacetonide as an alternative treatment for central giant-cell granuloma in 21 cases

Central giant-cell granulomas are benign, but occasionally aggressive, lesions that traditionally have been treated surgically. 21 cases of central giant-cell granuloma of the jaw were treated with intralesional injection of corticosteroids. The treatment protocol adopted was intralesional injection of 20 mg/ml triamcinolone hexacetonide diluted in an anaesthetic solution of 2% lidocaine/epinephrine 1:200,000 in the proportion 1:1; 1.0 ml of the solution was infiltrated for every 1 cm(3) of radiolucid area of the lesion, totalling 6 biweekly applications. Ten patients had aggressive lesions and 11 nonaggressive. Two patients showed a negative response to the treatment and underwent surgical resection, 4 showed a moderate response and 15 a good response. 8 of the 19 who had a moderate-to-good response to the drug treatment underwent osteoplasty to reestablish facial aesthetics. In these cases, only mature or dysplastic bone was observed, with the presence or absence of rare giant multinucleated cells. The advantages of this therapy are its less-invasive nature, the probable lower cost to the patient, lower risk and the ability to treat the lesion surgically in the future, if necessary.

Interactions between Siglec-7/9 receptors and ligands influence NK cell-dependent tumor immunosurveillance.

Alteration of the surface glycosylation pattern on malignant cells potentially affects tumor immunity by directly influencing interactions with glycan-binding proteins (lectins) on the surface of immunomodulatory cells. The sialic acid-binding Ig-like lectins Siglec-7 and -9 are MHC class I-independent inhibitory receptors on human NK cells that recognize sialic acid-containing carbohydrates. Here, we found that the presence of Siglec-9 defined a subset of cytotoxic NK cells with a mature phenotype and enhanced chemotactic potential. Interestingly, this Siglec-9+ NK cell population was reduced in the peripheral blood of cancer patients. Broad analysis of primary tumor samples revealed that ligands of Siglec-7 and -9 were expressed on human cancer cells of different histological types. Expression of Siglec-7 and -9 ligands was associated with susceptibility of NK cell-sensitive tumor cells and, unexpectedly, of presumably NK cell-resistant tumor cells to NK cell-mediated cytotoxicity. Together, these observations have direct implications for NK cell-based therapies and highlight the requirement to consider both MHC class I haplotype and tumor-specific glycosylation.

Decompression for Management of Keratocystic Odontogenic Tumor in the Mandible

Keratocystic odontogenic tumor (KCOT) is a benign intraosseous neoplasm of odontogenic origin with high recurrence rate. To date, various conservative or aggressive management strategies have been suggested as a method of treatment. Decompression is a conservative method that has been used in the treatment of large odontogenic cysts. The present paper reports a case of KCOT located in the mandible and discusses the importance of its management using conservative methods. The authors present a case of a 38-year-old patient with a KCOT located in the right mandibular angle and ascending ramus, which was treated by decompression followed by enucleation and curettage. The lesion did not recur during a follow-up period of 3 years after surgery. Preserving important structures of the bone and soft tissue decompression is a method with low morbidity. In addition, according to the literature, decompression has a success rate at least as high as the one of most aggressive treatments.

Immunoexpression of keratins in the calcifying cystic odontogenic tumor epithelium

Ameloblastomatous epithelium containing clusters of ghost cells is the typical histopathology of calcifying cystic odontogenic tumor (CCOT). This paper aimed to assess keratins AE1-AE3, K7, K10/13, K14, K18, K19, vimentin, laminin, and collagen IV in 08 CCOTs to discuss their histopathogenesis. Similarity to the immunoprofile of the stratified squamous epithelium was seen in the with the basal layer expressing K14 and the upper cells expressing K10/13. When compared to the immunoprofile of the normal odontogenic epithelium, of odontogenic tumor epithelia and of the ghost cells described in the literature, it was possible to suggest that the CCOT epithelium differentiates towards squamous type.

Conservative Management of a Large Keratocystic Odontogenic Tumor in the Maxilla

Keratocystic odontogenic tumor is characterized by high recurrence rates. Conservative or aggressive management has been suggested as a method of treatment. Decompression is a conservative treatment that has been used in the treatment of large odontogenic cysts. The authors report a case of a 14-year-old patient with a keratocystic odontogenic tumor located in the right maxilla, which was treated by decompression followed by enucleation with curettage. The lesion did not recur on follow-up for 3 years after the enucleation surgery.

Importance of cone beam computed tomography for diagnosis of calcifying cystic odontogenic tumor associated to odontoma. Report of a case

The calcifying cystic odontogenic tumour (CCOT) is a rare benign cystic neoplasm not infrequently associated with odontoma. This report documents a case of CCOT associated with compound odontoma arising in the anterior maxilla in a 25-year-old woman. Conventional radiographs showed a large calcified mass with poorly visualized radiolucent margins. The extent and condition of the internal structure of the CCOT associated with odontoma was able to be determined based on radiographic findings from cone beam computed tomography. This advanced image technique proved to be extremely useful in the radiographic assessment of this particular neoplasm of the jawbones.

Granular cell tumour (Abrikossoff's tumour): Case series

This case series describes three unreported cases of an uncommon benign neoplasm named Abrikossoff's tumour or granular cell tumour (GCT). This mesenchymal neoplasm apparently arises from neural or Schwann cell origin with benign and malignant forms. All cases presented here were unique nodules on oral mucosa, coming out from the connective tissue, and occurring in women with age ranging from 30 to 42 years. The histological aspects of the GCT showed large granular cells arranged in groups and nests of connective tissue separating pseudoepitheliomatous overlying surface. This feature can possibly be misunderstood with squamous cell carcinoma. The differentiation between malignant and benign GCT is evaluated by the presence of metastases which is considered the only reliable criterion for malignancy. © 2005 Elsevier Ltd. All rights reserved.

Conservative approach to the treatment of keratocystic odontogenic tumor

The odontogenic keratocyst, also known as the keratocystic odontogenic tumor, is an aggressive, intraosseous lesion of odontogenic origin that presents a high rate of recurrence. Treatment modalities include aggressive surgical procedures and more conservative approaches that significantly influence the lesion's recurrence potential. The purpose of this case report was to demonstrate a conservative approach in the treatment of an extensive keratocystic odontogenic tumor, located in the mandible's posterior region, using decompression and enucleation.

Detection of cytokeratins in ghost cells of calcifying cystic odontogenic tumor indicates an altered keratinization and hair follicle differentiation for their development

Calcifying cystic odontogenic tumors (CCOTs) are benign cystic lesions of odontogenic origin characterized by an ameloblastoma-like epithelium and the presence of a group of cells named ghost cells. The pattern of cytokeratin (Ck) expression on these lesions remains unclear and needs to be clarified. To this end, the expression of Ck6, Ck13, Ck14, Ck18, and Ck19 in the epithelium lining of 7 cases of CCOTs was evaluated by immunohistochemistry. For this, the epithelium lining was divided into 3 distinct regions: basal layer, suprabasal layer, and the compartment composed of ghost cells. In this study, 6 cases (85.7%) were classified as type 1 and 1 (14.3%) as type 4. All cases were negative for Ck13 and Ck18, despite the epithelial layer, as well as in the ghost cells. Ck6 was only positive in the ghost cells. Positivity for Ck14 and Ck19 was found in the basal and suprabasal layers, including the ghost cells. The results showing positivity for Ck14 and Ck19 in all of the analyzed cases reinforce CCOT as being of odontogenic origin, and the restricted expression of Ck6 in the ghost cells may be indicative that these cells suffer an altered differentiation into hair follicles in CCOTs. © 2013 Elsevier Inc. All rights reserved.

Total Spontaneous Regression of a Central Giant Cell Granuloma After Incisional Biopsy: A Four-Year Follow-Up Case Report

Central giant cell granuloma (CGCG) of the jaws represents a localized and benign neoplastic lesion sometimes characterized by aggressive osteolytic proliferation. The World Health Organization defines it as an intraosseous lesion composed of cellular and dense connective tissues that contain multiple hemorrhagic foci, an aggregation of multinucleated giant cells, and occasional bone tissue trabeculae. The origin of this lesion is uncertain; however, factors such as local trauma, inflammation, intraosseous hemorrhage, and genetic abnormalities have been identified as possible causes. CGCG generally affects those younger than 30 years and occurs more frequently in women (2: 1). This lesion corresponds to approximately 7% of all benign tumors of the jaws, with prevalence in the anterior region of the jaw. Aggressive lesions are characterized by symptoms, such as pain, numbness, rapid growth, cortical perforation, root resorption, and a high recurrence rate after curettage. In contrast, nonaggressive CGCGs have a slow rate of growth, may contain sparse trabeculation, and are less likely to move teeth or cause root resorption or cortical perforation. Nonaggressive CGCGs are generally asymptomatic lesions and thus are frequently found on routine dental radiographs. Radiographically, the 2 forms of CGCG present as radiolucent, expansive, unilocular or multilocular masses with well-defined margins. The histopathology of CGCG is characterized by multinucleated giant cells, surrounded by round, oval, and spindle-shaped mononuclear cells, scattered in dense connective tissue with hemorrhagic and abundant vascularization foci. The final diagnosis is determined by histopathologic analysis of the biopsy specimen. The preferred treatment for CGCG consists of excisional biopsy, curettage with a safety margin, and partial or total resection of the affected bone. Conservative treatments include local injections of steroids, calcitonin, and antiangiogenic therapy. Drug treatment using antibiotics, painkillers, and corticosteroids and clinical and radiographic monitoring are necessary for approximately 10 days after surgery. There are only a few cases of spontaneous CGCG regression described in the literature; therefore, a detailed case report of CGCG regression in a 12-yearold boy with a 4-year follow-up is presented and compared with previous studies. (c) 2014 American Association of Oral and Maxillofacial Surgeons

Central Giant Cell Granuloma in Pediatric Maxilla: Surgical Management

Central giant cell granuloma (CGCG) is an intraosseous lesion consisting of fibrous cellular tissue that contains multiple foci of hemorrhage, multinucleated giant cells, and occasional trabeculae of woven bone. An 8-year-old boy presented himself complaining of a painless swelling in the left maxilla that had started 1 year. Computed tomography (CT) scan confirmed a poorly defined multilocular radiolucent lesion in the left maxilla crossing the midline. The patient underwent enucleation through an intraoral approach of the lesion. The biopsy revealed multinucleated giant cells in a fibrous stroma. A CT was taken approximately 1 year postoperatively. There was no clinical or radiographic evidence of recurrence. Therefore, surgical treatment of CGCG can be performed, trying to preserve the surrounding anatomic structures, which can be maintained in case the lesion does not show an aggressive clinical behavior, avoiding large surgical defects which are undesirable in children.

Five years follow-up of a keratocyst odontogenic tumor treated by marsupialization and enucleation: a case report and literature review

Odontogenic cysts are considered as nonneoplasic benign lesions. Among the cysts, keratocyst odontogenic tumor (KCOT) is an intra‑osseous tumor characterized by parakeratinized stratified squamous epithelium and a potential for aggressive, infiltrative behavior, and for the possibility to develop carcinomas in the lesion wall. Thus, the aim of this study was to describe a clinical case of KCOT in a young patient and discuss the treatment alternatives to solve this case. A 15‑year‑old male was referred for treatment of a giant lesion in his left side of the mandible. After the biopsy, a diagnostic of KCOT was made, and the following procedures were planned for KCOT treatment. Marsupialization was performed for lesion decompression and consequent lesion size reduction. Afterward, enucleation for complete KCOT removal was performed followed by third mandibular molar extraction. After 5 years, no signs of recurrence were observed. The treatment proposed was efficient in removing the KCOT with minimal surgical morbidity and optimal healing process, and the first and second mandibular molars were preserved with pulp vitality. In conclusion, this treatment protocol was an effective and conservative approach for the management of the KCOT, enabling the reduction of the initial lesion, the preservation of anatomical structures and teeth, allowing quicker return to function. No signs of recurrence after 5 years were observed.