A comparative study of bone remodeling molecules expression in different types of jaw ameloblastoma.

BACKGROUND: Solid ameloblastoma demonstrates a more invasive behavior compared to unicystic. The follicular ameloblastoma is referred that may present a higher recurrence potential compared to the plexiform variant. In this study, the different ameloblastoma clinical types and histopathological variants were examined regarding the expression of bone remodeling-related molecules OPG, RANKL, and TRAIL. METHODS: Immunostained sections of 29 solid and 11 unicystic ameloblastoma cases were semi-quantitatively evaluated and analyzed using Mann-Whitney or Kruskal-Wallis tests. RESULTS: Solid ameloblastoma showed a significantly increased OPG expression (P = 0.004) associated with the follicular (P < 0.05) than the plexiform or mixed pattern. Lack or low immunoreactivity for RANKL was noted in 79.3% of the solid tumors. A statistically significant result (P < 0.05) was found in the unicystic ameloblastoma for differences by the histopathological pattern (no RANKL expression when plexiform pattern was seen compared to follicular). Comparison between the clinical types showed differences regarding the ratio of OPG/RANKL and TRAIL/RANKL expression. Higher OPG expression over RANKL was observed in 86.2% of the solid compared to 36.4% of the unicystic type. There was no difference in the ratio of TRAIL/RANKL expression in the unicystic, whereas 55.2% of the solid ameloblastomas showed a greater TRAIL expression over RANKL. CONCLUSIONS: Our results suggest OPG overexpression and RANKL underexpression in solid ameloblastoma; this may reflect a possible prevalence of the OPG/TRAIL over the OPG/RANKL signaling pathway, resulting in inactivation of TRAIL-induced apoptosis in ameloblastic cells. In unicystic ameloblastoma, the RANKL/OPG expression immunoprofile among histological variants is compatible with the reported biologic behavior.

Reactive osteocartilaginous metaplasia in denture wearers: a rare trauma-related lesion.

OBJECTIVE: To present a case of reactive osteocartilaginous metaplasia (ROCM) in the anterior edentulous mandibular ridge. BACKGROUND: The ROCM secondary to chronic mechanical denture trauma is rare and appears as a focal sometimes painful mass on or near the crest of the edentulous alveolar ridge in long-term denture wearers. The literature review disclosed 24 cases involving more commonly the posterior portion of the mandible. MATERIALS AND METHODS: An 80-year-old female was referred for the evaluation of a painful, submucosal nodule extending into the vestibular mucosa of the anterior edentulous mandibular region. Microscopically, cartilaginous regions exhibiting sparse hyperchromatic or binucleated chondrocytes transitioned into areas of ossification. RESULTS: The diagnosis was ROCM. The presence of osteocartilaginous tissue displaying bizarre histopathological features can create a diagnostic dilemma. CONCLUSION: Complete conservative surgical excision of this lesion has a very good prognosis. Surgical augmentation of the sharp edentulous mandibular ridges might be needed to avoid continuous irritation and possible recurrence.

Retrieval analysis of immediately loaded orthodontic mini-implants: material and tissue characterization.

OBJECTIVE: To investigate the morphological and compositional alterations of retrieved orthodontic mini-implants and the type of adjacent bone, in relation to loading period and anatomical region. MATERIALS AND METHODS: Seventy orthodontic mini-implants (Aarhus: n = 35 and AbsoAnchor: n = 35) were placed in the maxilla and mandible of 33 orthodontic patients for anchorage purposes. All mini-implants were immediately loaded for a period specified by treatment plan. Fifty-nine mini-implants were retrieved (Aarhus: n = 29 and AbsoAnchor: n = 30) and examined by stereomicroscopy, reflection Fourier transform infrared microspectroscopy, scanning electron microscopy, and energy dispersive X-ray spectroscopy. Tissue samples adjacent to the implants were histologically examined to identify the bone type. RESULTS: Changes in surface finish, formation of biological integuments, and compositional alterations mainly due to adsorption of proteinaceous material (rich in C, O, N, OH, NH, CH2/CH3, amide I, II, and III, and CH-OH) were identified in all mini-implants. In some cases, mineralized fragments were identified (rich in Ca, P, and Ca-P). In 25 out of the 59 histological sections examined, woven and lamellar bone types were detected. In 12 sections, only woven bone was detected, whereas in the residual 22, only lamellar bone was identified. A significant correlation was found between histological result and loading time but not between histology and region. CONCLUSION: Morphological and elemental alterations were found for both types of mini-implant surfaces. An increase of the loading period increased the possibility of lamellar bone development around mini-implants.

Odontogenic tumors.

PURPOSE: This study aims to analyze the frequency and distribution of odontogenic tumors in a Greek population and compare the findings with those reported in the recent literature. METHODS: Records of the Department of Oral Medicine and Pathology, Dental School, University of Athens, with histologic diagnosis of odontogenic tumors (based on the World Health Organization 2005 classification) were reviewed retrospectively from January 1970 to December 2011. RESULTS: A total of 652 cases of odontogenic tumors were reported. Of these, 651 (99.8%) were benign and only 1 (0.2%) was malignant. Keratocystic odontogenic tumor was the most frequent lesion (52.7%), followed by odontoma (18.9%) and ameloblastoma (16.1%). The mean age of patients was 38.0 years with a wide range (2.5-92 years). CONCLUSIONS: Odontogenic tumors are rare lesions and appear to show a definite geographic variation. In Athens, Greece, they are presented mainly by the keratocystic odontogenic tumor, odontoma, and ameloblastoma.

Hybrid odontogenic ghost cell tumor and cutaneous pilomatrixoma: a highly unusual coexistence.

This article describes the first published case of coexistence in a child of a rare hybrid odontogenic ghost cell tumor and a solitary cutaneous pilomatrixoma. An 11-year-old boy presented with a large well-defined unilocular radiolucent lesion in the right posterior mandible. Marsupialization followed by enucleation of the remaining lesion at a later period was the treatment of choice. Histopathologic analysis revealed a hybrid tumor demonstrating areas identical to calcifying cystic odontogenic tumor, ameloblastoma, ameloblastic fibro-odontoma, ameloblastic fibromyxoma, and adenoid odontogenic tumor. A cutaneous nodule was also removed from the facial area and demonstrated classic features of pilomatrixoma on histopathology. Sixteen cases of hybrid calcifying cystic odontogenic tumor associated with odontogenic tumors other than ameloblastomas and odontomas are referred in the literature to date. Young males are frequently affected, and the mandible is the most common site of involvement. The occurrence in the same patient of 2 distinctive entities, which both demonstrate ghost/shadow cells, may be a coincidental finding or suggest a common origin regarding the histogenesis of these cells. Alternatively, future molecular studies may clarify possible genetic or/and predisposing factors for the development of these lesions.

Effect of autologous platelet-rich plasma in combination with a biphasic synthetic graft material on bone healing in critical-size cranial defects.

PURPOSE: The aim of the study was to investigate the effect of autologous platelet-rich plasma (PRP) on the osteogenic potential of a biphasic synthetic graft material composed of hydroxyapatite and beta-tricalcium phosphate (HA/ß-TCP) in critical-size cranial defects in rabbits. MATERIALS AND METHODS: Three circular bicortical critical-size cranial defects were created in each of 18 rabbits. The first of the defects was grafted with autologous PRP and HA/ß-TCP, the second was grafted with HA/ß-TCP without PRP, and the third was left unfilled as a negative control. Animals were euthanized at 2, 4, and 6 weeks after surgery. Harvested tissue specimens were evaluated histologically and histomorphometrically. Several parameters associated with osteoclastic and osteoblastic activities were measured and calculated. The results were statistically analyzed using the 1-way analysis of variance statistical method. RESULTS: Histologic analysis of the samples showed bone tissue formation at all experimental sites including untreated control defects. A statistically significant difference in new bone formation between the defects treated with HA/ß-TCP + PRP and defects treated with HA/ß-TCP alone was not observed. Control untreated defects showed the greatest bone regeneration. CONCLUSIONS: In this animal model, autologous PRP had no effect on bone healing in addition to a biphasic HA/ß-TCP synthetic graft material after 2, 4, and 6 weeks of implantation.

Increased TNF-α, IL-6 and decreased IL-1ß immunohistochemical expression by the stromal spindle-shaped cells in the central giant cell granuloma of the jaws.

OBJECTIVES: the expression of the osteoclastogenic cytokines TNF-α, IL-6 and IL-1ß were immunohistochemically evaluated in peripheral (PGCG) and central (CGCG) giant cell granulomas of the jaws in order to determine differences between these two lesions and between the two distinct tumor cell populations (multinucleated giant cells, MGCs and stromal spindle-shaped cells). STUDY DESIGN: Paraffin-embedded tissue sections from 40 PGCG and 40 CGCG were immunohistochemically stained using antibodies against TNF-α, IL-6 and IL-1ß. The percentage of positively stained cells and the staining intensity were assessed to provide a combined immunoreactivity score value. RESULTS: TNF-α, IL-6 and IL-1ß were expressed in all lesions. The CGCG compared to the PGCG showed significantly increased expression of TNF-α and IL-6 and decreased expression of IL-1ß by the spindle-shaped cells and increased expression of IL-1ß by the MGCs. The MGCs demonstrated in comparison to the stromal spindle-shaped cells significantly increased expression of all three cytokines in both PGCG and CGCG. CONCLUSIONS: The proinflammatory cytokines TNF-α, IL-6 and IL-1ß seem to be involved in the growth process of PGCG and CGCG of the jaws. A possible alteration in the synthesis or/and activity of these cytokines by the stromal spindle cells in the CGCGs may enhance osteolysis through the stimulation of osteoclast progenitor cells, given the fact that the intraosseous lesions cause bone resorption.

A case of systemic precursor T-cell lymphoblastic lymphoma presenting with single tooth mobility.

Lymphoblastic lymphoma, seen primarily in children or young adults, is a type of non-Hodgkin lymphoma that originates from B or T lymphocyte precursors and rarely occurs in the oral cavity. A case of systemic precursor T-cell lymphoblastic lymphoma mimicking periodontitis of a lower second molar in a 20-year-old adult is currently presented. The case was initially misdiagnosed as periodontal disease and treated with tooth extraction by a dentist. Re-evaluation of the patient due to worsening of symptoms lead to cone beam computed tomography scanning that thoroughly revealed an extended osteolytic lesion of the right mandible. Afterward, a biopsy was performed, thus reaching the diagnosis of precursor T-cell lymphoblastic lymphoma. This report discusses differences in epidemiology of T-cell and B-cell lymphoblastic lymphomas, as well as their various intraoral manifestations that are mimicking a large family of oral pathology. It also focuses on conventional imaging findings that imply malignancy, which are often neglected during routine radiology interpretation.

Oral neural tumors: Clinicopathologic analysis of 157 cases and review of the literature.

BACKGROUND: Oral neural tumors (ONTs) are rare lesions and represent reactive or neoplastic proliferations of nerve sheath cells. The purpose of the present study is to report the clinical, demographic and histopathologic features of 157 ONTs diagnosed in a single Oral Pathology Department and review the pertinent literature. MATERIAL AND METHODS: 157 cases of ONTs diagnosed during a 44-year period were retrospectively collected and the diagnosis was reconfirmed by studying representative haematoxylin and eosin stained tissue sections. The patients' gender and age, as well as the main clinical features of the lesions, were retrieved from the biopsy submission forms. RESULTS: The 157 ONTs represented approximately 0.4% of 35,590 biopsies accessioned during the study period. They affected 71 male and 86 female patients with a mean age of 38.4±18.8 years. They mainly appeared as asymptomatic nodules of normal or white colour on the tongue, lip mucosa and hard palate. The most common ONT was granular cell tumour (38.9%) followed by neurofibroma (19.7%), schwannoma (15.9%), traumatic neuroma (15.9%), palisaded encapsulated neuroma (8.3%) and nerve sheath myxoma (1.3%). CONCLUSIONS: This study confirmed the rarity of ONTs. Their clinical characteristics mimic other oral lesions; thus, microscopic examination is the only mean to arrive at a definitive diagnosis. Key words:Oral neural tumors; oral neural neoplasms; neurofibroma; oral neurofibroma; schwannoma; oral schwannoma; neurilemmoma; oral neurilemmoma; granular cell tumor; oral granular cell tumor; traumatic neuroma; oral traumatic neuroma; palisaded encapsulated neuroma; oral palisaded encapsulated neuroma.

Infected lingual osseous choristoma. Report of a case and review of the literature.

Osseous choristoma is a rare, benign lesion of the oral cavity occurring usually in the tongue. It appears as a tumorous mass of normal bony structure with mature cells in an ectopic position. The case of a 72 years Caucasian male is presented and analyzed along with 52 similar cases reported in the English literature between 1967 and 2007. Lingual choristoma shows a female predilection, whereas the commonest anatomic location is the posterior third of the tongue, occurring at or close to the foramen caecum and the circumvallate papillae. Histologically the lesions show signs of a well-circumscribed mass of vital bone located under the surface oral epithelium. Some lesions represent developmental malformations, whereas others may be reactive lesions after trauma or chronic irritation. Treatment of lingual osseous choristoma consists of simple excision.

Oral Verruciform Xanthoma within Lichen Planus: A Case Report and Literature Review.

BACKGROUND: Verruciform xanthoma is an uncommon benign tumor, which exhibits a wide range of clinical patterns. The occurrence of the lesion in patients with immune-mediated mucocutaneous diseases may suggest a role of localized epithelial cell damage and chronic inflammation in its pathogenesis. CASE REPORT: A case of verruciform xanthoma on the tongue of a 56-year-old female with oral lichen planus is reported. An asymptomatic pink-white lesion with a granular surface was observed in the left lateral lingual border, which was closely associated with a white plaque and striae. An incisional biopsy was performed, and histologically, epithelial projections in a verrucous pattern were observed. In the subepithelial connective tissue, aggregates of foamy cells that exhibited immunoreactivity for CD68 were noted. The final diagnosis was verruciform xanthoma. The mucosa adjacent to the lesion demonstrated histopathological features consistent with lichen planus. CONCLUSIONS: A total of twelve cases of oral verruciform xanthomas in patients with oral lichen planus including the present case have been reported in the literature. The clinician should be aware that verruciform xanthoma may mimic malignancy, and therefore, biopsy is required for definitive diagnosis to be established, especially when this tumor develops within conditions that show potential for malignant transformation.

Atypical methotrexate ulcerative stomatitis with features of lymphoproliferative like disorder: Report of a rare ciprofloxacin-induced case and review of the literature.

Methotrexate (MTX) is an established immunomodulating agent used in low doses (LDMTX) to treat several autoimmune diseases. Ulcerative stomatitis (US) may be observed as a long-term LDMTX adverse effect showing a wide histopathologic spectrum. A 73-year old female presented with painful oral ulcers of 5 days duration. The patient had been under treatment for rheumatoid arthritis with LDMTX, while one week before presentation she was prescribed ciprofloxacin for a urinary infection. Histopathologic examination of a lingual ulcer revealed a polymorphous lymphohistiocytic proliferation with scattered binucleated atypical lymphocytes. Immunohistochemically, most cells were of T-cell lineage while the EBER test was negative and a diagnosis of MTX-induced reactive ulceration was rendered. MTX cessation resulted in complete resolution of the ulcers with no recurrences reported so far. The clinical and histopathologic features of MTX-induced oral ulcers are not always diagnostic and a detailed history and an extensive clinicopathologic investigation may be needed to exclude a lymphoproliferative disorder. Key words:Atypical oral ulcers, ciprofloxacin, lymphoproliferative disorders, methotrexate.

Immunohistochemical evaluation of cell proliferation antigen Ki-67 and apoptosis-related proteins Bcl-2 and caspase-3 in oral granular cell tumor.

PURPOSE: We sought to evaluate the cell proliferation activity and immunohistochemical expression of proteins that promote or inhibit apoptosis in oral granular cell tumor (GCT). STUDY DESIGN: Immunohistochemistry for Ki-67, a cell proliferation marker; Bcl-2, an anti-apoptotic protein; and caspase-3, a protein implicated in the execution of apoptosis, was performed on tissues from 12 patients with GCT of the tongue. RESULTS: Nuclear immunostaining for Ki-67 was observed only in isolated GCs (less than 2%). All patients exhibited cytoplasmic immunoreactivity for Bcl-2 in the majority of tumor cells. Cytoplasmic staining for caspase-3 was also present in more than 50% of GCs in all tumors. CONCLUSIONS: GCT cells display low proliferation activity, a finding possibly related to their benign behavior. Caspase-3 expression suggests activation of the apoptotic cascade in the GCs, but persistence of the cells in the tissues could be attributed to the expression of Bcl-2 protein, a molecule that functions as a survival factor.

Atypical Presentation of an Upper Lip Pleomorphic Adenoma: Case Report.

The pleomorphic adenoma (PA) or mixed tumor is the most common neoplasm of the salivary glands, usually presenting with a non-specific clinical manifestation and a diverse histopathological pattern. The region of the lips is the second most common site for minor gland neoplasms. The aim of this paper is to report the case of a 39 year old caucasian woman presenting with a swelling on the right side of the upper lip combined with a history of trauma in the region of the upper right central incisor, eight years ago. The swelling was attributed to the periapical lesion of the upper right central incisor that was observed on the orthopantomography. Intraoperatively the surgeon came upon a nodule of firm consistency in the mucolabial fold. The histopathologic diagnosis of this lesion was benign mixed tumor of salivary gland. This report discusses the deviation in frequency of mixed salivary gland tumor between upper and lower lip, the clinical differential diagnosis, the histopathological pattern and the appropriate treatment.

Evaluation of lateral thermal damage and reepithelialization of incisional wounds created by CO2-laser, monopolar electrosurgery, and radiosurgery: a pilot study on porcine oral mucosa.

OBJECTIVE: This study aims to compare lateral thermal damage (LTD) produced by CO(2)-laser, monopolar electrosurgery (MES), and radiosurgery (MRS) and its effects on the reepithelialization of oral mucosa incisional wounds. STUDY DESIGN: Five adult swine were submitted to standardized incisions at the tongue and gingiva by MES, MRS, CO(2)-laser and scalpel. Full-thickness specimens were harvested sequentially on days 1 and 3. All specimens were formalin fixed, paraffin embedded, cut, and stained with hematoxylin-eosin to quantify LTD extent. Sections of day 3 were stained for Ki-67 to assess epithelial proliferation at the incision margins. A multiple linear regression model and an analysis of variance were used to determine the correlation of each instrument with LTD extent and Ki-67 expression respectively. RESULTS: LTD was most extensive in the CO(2)-laser but did not differ between the MES and MRS groups. No statistically significant differences regarding reepithelialization were noted among the investigated instruments. CONCLUSIONS: CO(2)-laser produced more extensive LTD, without evident impact on reepithelialization.

Comparison of lateral thermal injury and healing of porcine skin incisions performed by CO2-laser, monopolar electrosurgery and radiosurgery: a preliminary study based on histological and immunohistochemical results.

BACKGROUND: Despite the wide application of lasers and electrosurgery in dermatology, the pertinent literature provides conflicting data regarding the lateral thermal injury (LTI) associated with these instruments and its effects on wound healing. This study aims to quantitate the LTI produced by CO(2)-laser, monopolar electrosurgery (MES), and radiosurgery (MRS) and determine its effects on the healing process (re-epithelialization and inflammatory response) of incisional wounds. METHODS: Five adult swine of similar weight (22.8-25 kg) were submitted to standardized full-thickness incisions on the lateral abdominal skin by the above instruments (at settings similar to those used in clinical practice) and scalpel (control group). Full-thickness specimens from the surgical site were harvested immediately afterwards and 48 hours later (days 1 and 3). The animals were euthanized by intravenous administration of propofol and pentobarbital. All specimens were formalin fixed, paraffin embedded, cut, and stained with hematoxylin-eosin to quantitate the extent of LTI and inflammatory infiltration. Sections of day 3 were stained with the MIB-1 monoclonal antibody to detect Ki-67 as a marker of epithelial cell proliferation adjacently to the incisions. RESULTS: LTI was most extensive in the CO(2)-laser-group but did not differ significantly between MES- and MRS-groups. Immunohistochemistry ascertained significantly greater epithelial cell proliferation in the CO(2)-laser-group. Inflammatory infiltration was significantly greater in the CO(2)-laser-group, when compared with the controls but did not differ significantly between the MES/MRS and control groups. CONCLUSION: CO(2) laser incisions exhibit more extensive LTI, epithelial cell proliferation, and inflammatory response. Confirmation of these findings requires a greater sample.

Novel mutations of the HRAS gene and absence of hotspot mutations of the BRAF genes in oral squamous cell carcinoma in a Greek population.

Oral squamous cell carcinoma (OSCC) is the sixth most common cancer in the world. The phosphatidylinositol 3 kinase (PI3K) signalling pathway has been reported to play an important role in OSCC. Since we have previously detected absence of hotspot PIK3CA gene mutations in the Greek population, we hypothesized that BRAF or HRAS may be activated as upstream effectors of the pathway. Furthermore, the status of the HRAS and BRAF mutations in OSCC has never been assessed before in the Greek population. Eighty-six primary paraffin-embedded tumors were screened for BRAF and HRAS hotspot mutations. In HRAS, two hotspot mutations in codon 12 (2.3%) and eight new genetic alterations were detected (8.6% overall). One new missense mutation, Alanine53Valine (Ala53Val), one silent mutation, two mutations in the 5'UTR region and four mutations in intron 1 were detected. No hotspot mutations in Braf were found. A new silent mutation/polymorphism T1803C was detected at a percentage of 30%. This study is the first to report HRAS mutations in the Greek population. The results suggest that RAS is an important member of the PI3K signalling pathway and may play a role in the tumorigenesis of OSCC.

Oral acanthosis nigricans in chronic hepatitis B with a 21-year follow up.

Acanthosis nigricans is a rare mucocutaneous disorder of unknown etiology that manifests as hyperpigmented velvety plaques, most often on intertriginous areas such as the neck and axillae as well as on mucosal sites such as the oral cavity. The disorder presents either as a paraneoplastic manifestation of an underlying malignancy, especially gastrointestinal adenocarcinomas or in association with obesity, administration of drugs or endocrinopathies, most commonly insulin-resistant diabetes mellitus. In the present article, a case of acanthosis nigricans with oral and cutaneous manifestations in a male patient with chronic hepatitis B infection is described. To the best of our knowledge, this is the first case of benign oral acanthosis nigricans associated with chronic hepatitis B.

Oral nodular fasciitis: report of a case of the buccal mucosa.

Nodular fasciitis is a benign, reactive, proliferative spindle-cell lesion, usually located at the subcutaneous tissues or muscle fascia. Clinically, it manifests as a soft-tissue mass with well-defined margins and fixed to the adjacent structures. Because of its rapid growth rate, rich cellularity and relatively high mitotic activity, nodular fasciitis is sometimes misdiagnosed as a sarcoma. Accurate diagnosis is based only on histopathological examination. A rare case of nodular fasciitis of the buccal mucosa in a 50-year-old female patient is presented.