Odontogenic carcinoma with dentinoid: case report and literature review of a rare entity.

BACKGROUND: Odontogenic carcinoma with dentinoid (OCD) is a rare and controversial entity, which has not yet been included in the current World Health Organization classification of odontogenic lesions. Owing to the small number of reported cases, the clinicopathological characteristics, biological behavior, prognosis, and appropriate treatment strategies for OCD remain to be defined. Herein, we present an additional case of OCD with a focus on the differential diagnosis and review of the pertinent literature, in order to enable better recognition by oral clinicians and pathologists and further characterization of this entity. CASE PRESENTATION: This paper reports a case of OCD in the posterior mandible of a 22-year-old female. Radiography showed a well-defined unilocular radiolucency with radiopaque materials. The intraoperative frozen section pathology gave a non-committed diagnosis of odontogenic neoplasm with uncertain malignant potential. Then a partial mandibulectomy with free iliac crest bone graft and titanium implants was performed. Microscopically, the tumor consisted of sheets, islands, and cords of round to polygonal epithelial cells associated with an abundant dentinoid matrix. Immunohistochemically, the tumor cells were diffusely positive for CK19, p63, and ß-catenin (cytoplasmic and nuclear). No rearrangement of the EWSR1 gene was detected. The final diagnosis was OCD. There has been no evidence of recurrence or metastasis for 58 months after surgery. We also provide a literature review of OCD cases, including one case previously reported as ghost cell odontogenic carcinoma from our hospital. CONCLUSIONS: OCD is a locally aggressive low grade malignancy without apparent metastatic potential. Wide surgical excision with clear margins and long-term period follow-up to identify any possible recurrence or metastases are recommended. Histopathological examination is essential to conclude the diagnosis. Special care must be taken to distinguish OCD from ghost cell odontogenic carcinoma and clear cell odontogenic carcinoma, as misdiagnosis might lead to unnecessary overtreatment. Study of additional cases is required to further characterize the clinicopathological features and clarify the nosologic status and biological behavior of this tumor.

Preparation of Inert Polystyrene Latex Particles as MicroRNA Delivery Vectors by Surfactant-Free RAFT Emulsion Polymerization.

We present the preparation of 11 nm polyacrylamide-stabilized polystyrene latex particles for conjugation to a microRNA model by surfactant-free RAFT emulsion polymerization. Our synthetic strategy involved the preparation of amphiphilic polyacrylamide-block-polystyrene copolymers, which were able to self-assemble into polymeric micelles and "grow" into polystyrene latex particles. The surface of these sterically stabilized particles was postmodified with a disulfide-bearing linker for the attachment of the microRNA model, which can be released from the latex particles under reducing conditions. These nanoparticles offer the advantage of ease of preparation via a scaleable process, and the versatility of their synthesis makes them adaptable to a range of applications.

Synchronous occurrence of odontogenic myxoma with multiple keratocystic odontogenic tumors in nevoid basal cell carcinoma syndrome.

The keratocystic odontogenic tumor (KCOT) is a benign developmental tumor with many distinguishing clinical and histologic features. Usually, multiple KCOTs occur as a component of nevoid basal cell carcinoma syndrome. The odontogenic myxoma is a rare benign tumor that represents about 3% of all odontogenic tumors. This article reports the case of mandible odontogenic myxoma with synchronous occurrence of multiple KCOTs, partial expression of nevoid basal cell carcinoma syndrome. A review of the international literature is also presented.

Dentinogenic ghost cell tumor revisited from a single institution in China with focus on adenoid ameloblastoma-like features.

OBJECTIVE: The present study aims to identify adenoid ameloblastoma (AdAM) from previously diagnosed cases of dentinogenic ghost cell tumor (DGCT), and gain insight to the possible relationship between AdAM and DGCT. METHODS: DGCT cases diagnosed between 2006 and 2022 were re-examined with focus on the AdAM-like features. RESULTS: A total of nine patients were included. Seven patients were males and two were females. The mean age was 38.0 ± 16.0 years. Five tumors occurred in the maxilla and four in the mandible, with a remarkable predilection for the posterior regions of both jaws. Microscopically, dentinoid material deposition was present in all cases. The ghost cells were absent in two cases. Rare ghost cells (<1%) were observed in three cases, and a higher proportion of ghost cells (5%-20%) were present in the remaining four cases. All cases showed prominent AdAM-like features, including duct-like structures, whorls/morules, and cribriform architecture. According to the diagnostic criteria proposed by the 2022 WHO classification, five cases without or with rare ghost cells were reclassified as AdAM. The other four cases including a higher proportion of ghost cells consisted of a mixture of DGCT and AdAM histopathologic patterns. CONCLUSION: Our results confirmed that the AdAM-like features had been largely overlooked in the diagnosis of DGCT at our institution in the past. Whilst a subset can now be more accurately classified as AdAM, some tumors showed overlapping morphological features between AdAM and DGCT, suggesting that the two may represent a spectrum of the same entity.

Clinical and radiologic features of desmoplastic ameloblastoma.

PURPOSE: To evaluate the clinical and radiologic features of desmoplastic ameloblastoma (DA). MATERIALS AND METHODS: Twenty-four cases of DA among Chinese patients were analyzed retrospectively. The clinical and radiologic features of DA at present, as reported in the English-language literature, were reviewed and its radiologic characteristics critically evaluated. RESULTS: This study included 23 cases of intraosseous lesions and 1 case of extraosseous lesion. Clinically, DA is mainly located in the anterior and/or the premolar region of the jaw, with a slight male prominence. Among 23 intraosseous lesions, 9 cases occurred in the maxilla and 14 occurred in the mandible. Radiographically, 69.6% (16 of 23) exhibited ill-defined borders. Root displacement occurred in 47.9% of patients (11 of 23) and root resorption occurred in 8.7% of patients (2 of 23). Three radiologic presentations of DA were identified as follows: type I, which is both radiolucent and radiopaque in appearance (osteofibrosis type); type II, which has a completely radiolucent appearance (radiolucent type); and type III, which is both radiolucent and radiopaque in appearance combined with a large radiolucent change (compound type). The osteofibrosis type (14 cases) is the most common pattern, and the compound type is the least common (only 3 cases). CONCLUSIONS: DA has a potentially aggressive behavior. Moreover, it exhibits 3 different radiologic characteristics. Although DA should be differentiated from osteofibrosis lesions frequently described in the literature, some uncommon radiographic patterns should be considered in the differential diagnosis of this rare odontogenic tumor.

Tubulopapillary hidradenoma-like tumor of the mandible: Two case reports of an underrecognized entity.

Tubulopapillary hidradenoma-like tumor of the mandible is extremely rare, with only 3 cases published in the English-language literature. The clinicopathological characteristics and histogenesis of this tumor are unclear. Few pathologists and perhaps fewer clinicians are familiar with this entity, and it is likely underrecognized and under-reported. Herein, we present two additional cases, both misdiagnosed as malignancies preoperatively and postoperatively by different unwary pathologists. Awareness and knowledge of this enigmatic entity and its clinical and radiographic features, together with careful morphological assessment should enable the correct diagnosis and prevent unnecessary treatment.

Benign fibro-osseous lesions of the jaws: a study of 127 Chinese patients and review of the literature.

The aim of this study is to analyze all the cases of benign fibro-osseous lesions treated at School and Hospital of Stomatology, Wuhan University, to compare the results obtained in this study with those previously documented by other authors. The 127 cases diagnosed as a fibro-osseous lesion were retrieved, and information about these lesions was documented. In all, 127 cases of benign fibro-osseous lesions were surgically treated. Of these, 55 were cemento-ossifying fibroma, 43 ossifying fibroma, and 29 fibrous dysplasia. Cemento-ossifying fibromas mostly occur in men of the second decades, mostly in the mandible. Ossifying fibromas had almost equal sex predilection and age distribution peaked in the second decades, mostly in the mandible. Fibrous dysplasia also had equal sex predilection, and age distribution peaked in the second and third decades, with equal occurrence in both jaws. The tumors needed to have a regular follow-up after the surgery.

Fluorescent Labeling and Biodistribution of Latex Nanoparticles Formed by Surfactant-Free RAFT Emulsion Polymerization.

The authors report the preparation of a novel range of functional polyacrylamide stabilized polystyrene nanoparticles, obtained by surfactant-free reversible addition-fragmentation chain transfer (RAFT) emulsion polymerization, their fluorescent tagging, cellular uptake, and biodistribution. The authors show the versatility of the RAFT emulsion process for the design of functional nanoparticles of well-defined size that can be used as drug delivery vectors. Functionalization with a fluorescent tag offers a useful visualization tool for tracing, localization, and clearance studies of these carriers in biological models. The studies are carried out by labeling the sterically stabilized latex particles chemically with rhodamine B. The fluorescent particles are incubated in a healthy human renal proximal tubular cell line model, and intravenously injected into a mouse model. Cellular localization and biodistribution of these particles on the biological models are explored.

Epithelial expression of SHH signaling pathway in odontogenic tumors.

Sonic hedgehog (SHH) signaling pathway plays a critical role in tooth development. Recent studies indicate that SHH signaling pathway activation occurs both in the odontogenic cyst and ameloblastoma. However, the association of SHH pathway with other subtypes of odontogenic tumor is not well documented. The objective of this paper is to investigate the protein distribution of SHH and its receptor PTC, SMO and transcription factor GLI1 in various odontogenic tumors. Odontogenic tumor tissues including 34 epithelial derived, 24 epithelial-mesenchymal derived, and 26 mesenchymal derived were examined by immunohistochemistry for SHH, PTC, SMO and GLI1. Immunoreactivity for SHH, PTC, SMO and GLI1 was detected in both epithelial derived odontogenic tumors and epithelial-mesenchymal derived odontogenic tumors with or without dental hard tissue formation. Mesenchymal derived odontogenic tumors showed no positive staining except for the focal epithelial cells in island or cord forms within the central portion of the tumor. The protein expression of SHH signaling pathway in malignant odontogenic tumors was no stronger than that in benign tumors. Each of the genes in the pathway was expressed in similar patterns in the same tumor subtype. SHH, PTC, SMO and GLI1 were detected more in the cytoplasm of the epithelial cells than in stromal cells. Immunoreactivity for GLI1 was also detected in the base membrane of the tumor cells. The findings suggest SHH, PTC, SMO and GLI1 protein are predominantly located in epithelial components in various odontogenic tumors and might participate in the proliferation of epithelial components of odontogenic tumors.

Primary small cell neuroendocrine carcinoma of the oral cavity: A case report and review of the literature.

Small cell neuroendocrine carcinoma (SNEC) of the oral cavity is a rare and distinctive tumor with aggressive clinical behavior. Thus far, only a small number of cases have been reported and no definitive standard treatment strategy has been determined. The current study reports a case of oral SNEC arising in the lower gingiva in a 73-year-old male. Computed tomography displayed a relatively well-defined mass measuring 2.8×2×1.4 cm in size. The mass was located in the buccal side of the right mandibular posterior gingiva and exhibited no bony involvement. Histopathological examination revealed a proliferation of small cells with ovoid- to spindle-shaped nuclei, fine granular chromatin, inconspicuous nucleoli, scant cytoplasm and high mitotic activity. Immunohistochemically, the tumor cells were positive for cytokeratin AE1/AE3, chromogranin A, synaptophysin and neuron-specific enolase. Surgical resection and radical neck dissection were performed prior to the administration of adjuvant chemotherapy with a combination of cisplatin and etoposide. No evidence of local recurrence or metastasis was observed at 14 months post-surgery.

Clinical review of 580 ranulas.

OBJECTIVE: The purpose of this paper was to compare clinical features among 3 patterns of ranula and the recurrence rates of each when treated by different surgical methods. METHODS: A retrospective review of clinical and pathologic records in 580 ranulas was undertaken. Ranulas were classified into 3 clinical types according to sites of the primary swelling: oral ranula, plunging ranula, and mixed ranula. Information was collected on age at presentation, sex, history of onset, sites of swelling, surgical methods, histological findings, and outcome of treatment. RESULTS: Ranula was most prevalent in the second decade of life and slightly more common in females (male to female ratio of 1:1.2), but a distinct male predilection was noted for the plunging ranula (male to female ratio of 1:0.74). Oral ranula was most commonly involved in the left side (left to right ratio of 1:0.62), while the plunging and mixed ranula were commonly involved in the right side (left to right ratio of 1:1.38, 1:1.16 respectively). In the plunging ranula group, there were more patients who had the history more than 6 months. The recurrence rates of ranulas were not related to swelling patterns and surgical approaches, but intimately related to the methods of surgical procedures. The recurrent rates for marsupialization, excision of ranula, and excision of the sublingual gland or gland combined with lesion were 66.67%, 57.69%, and 1.20%, respectively. CONCLUSION: Three patterns of ranula have similar clinical and histopathologic findings, although plunging ranula has some different clinical features. Removal of the sublingual gland via an intraoral approach is necessary in the management of various clinical patterns of the ranula. Recurrence rates of ranulas of any type are excessive unless the involved sublingual gland is removed.

[The effect of rehabilitation of flared root canal on the fracture resistance of root and post-core system].

OBJECTIVE: To assess the effect of rehabilitation of flared root canal on the fracture resistance of root and post-core system. METHODS: Thirty-two simulated tooth roots made of polymethyl methacrylate were divided into 4 groups, including the normal root canal group and 3 flared root canal groups. One flared root canal group was rehabilitated by light-cared composite, another group was rehabilitated by amalgam, and the third flared root conal group was not treated. Casting post and core restored every simulated tooth root. Each specimen was embedded in acrylic resin and then fixed in a special jig on the universal load-testing machine. A compressive load was applied at a 90-degree angle to the long axis of the core until fracture, at a crosshead speed of 1 mm/min; the maximum of load was recorded. RESULTS: The means of load in normal root canal group, light-cared composite rehabilitated group, amalgam rehabilitated group, not treated group were 202.92 N, 194.60 N, 146.89 N, 142.09 N. It was shown that the load of normal root canal group is significantly greater than the load of not-treated group (P < 0.01); the light-cared composite rehabilitated group is significantly stronger than the not-treated group (P < 0.01), but there is no significant difference between the light-cared composite rehabilitated group and normal root canal group, and no significant difference between the amalgam rehabilitated group and not-treated group (P > 0.05). CONCLUSION: The rehabilitation of flared root canal using suitable material not only changes the shape of root canal, but also increases the fracture resistance of root canal because of its thicker and stronger root canal wall which obviously improves the fracture resistance of post and core.

Central mucoepidermoid carcinoma: a clinicopathologic and immunohistochemical study of 39 Chinese patients.

Central mucoepidermoid carcinoma (MEC) is a rare neoplasm arising intraosseously in the jaws. To clarify the clinicopathologic profile and pathogenesis of central MEC, clinicopathologic findings and follow-up data of 39 cases were collected and analyzed. There were 16 male and 23 female patients (median age, 43 y). Sixteen cases affected the maxilla, and 23 occurred in the mandible. Radiographically, most cases (32 of 39) showed a unilocular or multilocular radiolucency with bone destruction, and 7 were found with scattered calcification. The margins of the lesions were ill defined or diffused in 14 cases and relatively well defined in 25 cases. Most cases (26 of 39) were classified as low-grade MECs, whereas 13 were moderate-to-high grade. Follow-up data were available for 35 patients with a median period of 36 months. All cases were found to be primary; local recurrence occurred in 8 cases, most (75.0%) of which were low-grade tumors. Four cases showed regional lymph node metastasis, and 1 developed distant metastasis. Of 11 cases with a clinical history of the jaw cyst, 8 initially showed a typical odontogenic cyst with local MEC-like proliferation. In summary, the most likely pathogenesis of central MEC is neoplastic transformation of the epithelial lining of an odontogenic cyst, diagnosis of which should be based on clinical, radiographic, and histopathologic findings. The immunohistochemical profile of keratins is helpful in differential diagnosis. Radical surgery is the treatment of choice, whereas the role of radiotherapy or chemotherapy is still controversial, and careful long-term follow-up is necessary.

Calcifications in clear cell mucoepidermoid carcinomas.

Information concerning calcifications in clear cell mucoepidermoid carcinoma (MC) of the salivary gland is very scarce, with only 2 earlier reports in the literature. Seven cases of clear cell MC in our institution were reviewed. Unexpectedly, frequent calcifications were confirmed microscopically in 2 cases. This finding suggests that clear cell MC should be considered in the differential diagnosis of salivary gland tumors with calcification.

[Expression of p-p38MARK, uPA and Ki-67 in epithelial odontogenic tumour].

OBJECTIVE: to examine the expression of phosphorylated p38 mitogen-activated protein kinase (p-p38MAPK), urokinase plasminogen activator (uPA) and Ki-67. METHODS: the specimens of ameloblastoma (AB), keratocystic odontogenic tumour (KCOT), calcifying epithelial odontogenic tumor (CEOT), adenomatoid odontogenic tumour (AOT), calcifying cystic odontogenic tumour (CCOT) and 5 tooth germs were examined immunohistochemically for the expression of p-p38MAPK, uPA and Ki-67. RESULTS: p-p38MAPK was detected both in the cytoplasm and the nucleus of the epithelial odontogenic tumour cells and uPA in the cytoplasm of the epithelial odontogenic tumour cells. Among the 65 cases, there were 17 (26%), 51 (78%) and 62 cases (95%) of positive expression of p-p38MAPK, uPA and Ki-67 protein respectively. Furthermore, there was a statistically significant difference in the expression of p-p38MAPK, uPA and Ki-67 between epithelial odontogenic tumor group and tooth germ group (P < 0.05). There were significant correlations among the expression of p-p38MAPK, uPA and Ki-67 (P < 0.05). CONCLUSIONS: the p38MAPK-signaling pathway could promote tumour growth and invasion in epithelial odontogenic tumour by up-regulating uPA protein expression and may play a role in oncogenesis, invasion and proliferation of epithelial odontogenic tumour.

Myoepithelial carcinoma of intraoral minor salivary glands: a clinicopathological study of 7 cases and review of the literature.

OBJECTIVE: Myoepithelial carcinoma (MC), also known as malignant myoepithelioma, is a rare malignant salivary gland neoplasm with a predilection for the parotid gland. We present the clinicopathological and immunohistochemical features of 7 cases of intraoral MC in attempt to better understanding this entity. STUDY DESIGN: Seven intraoral MCs were retrieved from the files of the Department of Oral Pathology, School of Stomatology, Wuhan University, during a 10-year period. Immunohistochemical markers, including cytokeratin (CK) AE1/AE3, S100, vimentin, smooth muscle actin (SMA), p63, and maspin, were used to further characterize these lesions. A review of contemporary relevant literature is also provided. RESULTS: The patients were 5 women and 2 men, and the age range was 37 to 75 years (mean 57.9 years). Three cases arose in the hard palate, 2 in the retromolar region, and 1 each in the tongue and the floor of the mouth. Histologically, the tumors exhibited a solid architecture with cells arranged in nodules, nests, trabeculae, or cords. The epithelioid cell type is the most frequently encountered, followed by clear cells. The tumor-associated matrix is more prevalent hyalinized than myxoid. Immunohistochemically, CK AE1/AE3, S100, vimentin, p63, and maspin were expressed in all cases. Positivity for SMA was seen in 3 tumors. Five patients with follow-up information showed no evidence of disease after a mean follow-up of 69.6 months (range 22-108 months). CONCLUSIONS: Combining the current series with 21 additional cases in the literature indicated that myoepithelial carcinoma of intraoral minor salivary glands is generally a low-grade malignant tumor with little propensity for regional or distant metastasis and low recurrence. Awareness of the clinicopathological and immunohistochemical features of intraoral MC is necessary for accurate diagnosis. Wide local excision with tumor-free margins is the treatment of choice.

The expression of NF-kappaB, Ki-67 and MMP-9 in CCOT, DGCT and GCOC.

Calcifying odontogenic cysts (COCs) represent a group of rare odontogenic lesions with a diversity of clinicopathological and behavioral features. According to the WHO classification of head and neck tumors in 2005, COC has been divided into calcifying cystic odontogenic tumor (CCOT), dentinogenic ghost cell tumor (DGCT) and ghost cell odontogenic carcinoma (GCOC). With few reports available on its immunohistochemical profile, this study investigated the histopathological features and the expression of nuclear factor kappaB (NF-kappaB), Ki-67 and matrix metalloproteinase-9 (MMP-9) in CCOT, DGCT and GCOC. According to the WHO classification of head and neck tumors in 2005, 26 cases of the so-called COC were diagnosed as CCOT (n=14), DGCT (n=7) and GCOC (n=5), respectively. The specimens of 26 COCs and 10 classic ameloblastomas (as control group) were examined by immunohistochemistry using anti-NF-kappaB p65, anti-Ki-67 and anti-MMP-9 antibodies and by in situ hybridization(ISH)using anti-MMP-9 mRNA probes. Immunohistochemical reactivity for NF-kappaB was mainly detected in the cytoplasm of tumor cells, and nuclear reactivity was only seen in few tumor cells in COC and classic ameloblastomas. Rate of nuclear staining was less than 1%. The expression of Ki-67 in GCOC was significantly higher than those in CCOT (p<0.001), DGCT and ameloblastoma (p<0.005). In COCs and ameloblastomas, expression of MMP-9 mRNA and protein was detected in tumor cells as well as in stromal cells. The positive staining for MMP-9 protein was detected in stromal cells of all GCOC cases and was significantly stronger than those in CCOT and DGCT groups (p<0.05). NF-kappaB may minimally affect the progression and local invasiveness of CCOT, DGCT and GCOC. GCOC show significantly higher proliferative activity than CCOT and DGCT. MMP-9 in stroma is associated with invasive ability of the CCOT, DGCT and GCOC.

The adverse effect of self-etching adhesive systems on dental pulp after direct pulp capping.

OBJECTIVES: To evaluate the histopathological changes in mechanically exposed dog pulps capped with three self-etching adhesive systems. MATERIAL AND METHODS: Seventy-two Class V cavities were prepared under rubber dam isolation in dogs. The pulps were exposed and capped with Clearfil SE Bond (Kuraray), Imperva FluoroBond (Shofu), Prompt L-Pop (3M ESPE), and Dycal (Dentsply; control capping agent), respectively. Histopathological examination of the teeth was performed at 7, 14, and 30 days postoperatively. Hematoxylin-eosin staining was performed to assess the inflammatory cell response, tissue disorganization, and hard tissue formation. Brown and Brenn staining was used to detect the presence of bacteria. The data were analyzed by Kruskal-Wallis and Nemenyi tests. RESULTS: Most pulps showed moderate to severe inflammatory responses. Hard tissue formation appeared at 14 to 30 days. Positive bacterial staining was observed in most specimens in experimental groups. The histological changes in the pulps of the experimental groups were more pronounced than in the control group. Differences in inflammatory response, tissue disorganization, and hard tissue formation were observed among teeth treated with the three self-etching systems. CONCLUSION: Microleakage has a critical influence on pulpal repair. It is not beneficial to cap the pulp with self-etching adhesive systems. Diverse pulpal responses were observed to the self-etching adhesive systems, and the histological changes were more pronounced than in the control pulps treated with Dycal. The effects of the self-etching adhesive systems are such that these materials require further study to address issues of bacterial microleakage during placement of restorations.

Gingival squamous cell carcinoma in young patients: report of a case and review of the literature.

Squamous cell carcinoma is a malignant neoplasm of epithelium, most frequently occurring in intraoral tumors. In this article we describe a rarely reported, because the frequency of oral cancer in young people is extremely low, case of a 16-year-old Chinese girl with squamous cell carcinoma of anterior mandibular gingiva. The clinicopathologic features, etiology, clinical evaluation, management of squamous cell carcinoma of gingiva in young patients are discussed and the applicable literatures are reviewed.