Sclerosing Odontogenic Carcinoma With a Prominent Clear Cell Component Mimicking Odontogenic Clear Cell Carcinoma: An Extremely Rare Case With a Fatal Clinical Outcome.

Sclerosing odontogenic carcinoma (SOC) is an exceedingly rare odontogenic carcinoma known for its locally aggressive yet indolent behavior. There have been no reports of metastasis to distant organs, except a single case involving lymph node metastasis. This report details the case of a 49-year-old female who presented with a well-demarcated radiolucent lesion in the mandible, accompanied by root resorption and tooth displacement. Microscopically, the lesion exhibited a distinctive composition, with two distinct components: cords of epithelium embedded within an abundant collagenous stroma and solid nests of clear polygonal cells surrounded by hyalinized stroma. Notably, the tumor exhibited direct invasion into the submental muscles, accompanied by perineural and vascular invasion, as well as cortical bone loss. Additionally, the clear cells contained diastase-sensitive periodic acid-Schiff-positive granules. Immunohistochemically, the tumor cells displayed positivity for cytokeratin 19 and p63 while testing negative for myoepithelial markers. The Ki-67 index was measured at 23%. Importantly, neitherEWSR1 nor MAML2 rearrangements were detected through fluorescence in situ hybridization (FISH) analysis. Over several years, this patient experienced three instances of local recurrence; notably, four years after the initial surgery, fludeoxyglucose F18-positron emission tomography (18FDG-PET)/CT scans confirmed the presence of pulmonary metastasis. This case presents an unusual histological variation of SOC, marked by vascular invasion, and is notably the first documented case of a fatal outcome in this context.

Pharyngeal Deposits Comprising Salivary Mucin in Tube-fed Elderly Patients: MUC2 and MUC7 Immunoreactivity.

Several investigators have reported that oral membranous and pharyngeal viscous deposits developed in bedridden elderly persons requiring nursing care without oral intake. Therefore, this study aimed to clarify the origin of viscous deposits on the pharyngeal mucosa based on characteristics of salivary and tracheal secretory mucin. The participants were 35 elderly people who required nursing care. All 46 collected specimens, including 30 intraoral and 16 pharyngeal specimens, were stained against specific mucins secreted from the respiratory tract and saliva gland using antibodies anti-MUC2 and anti-MUC7, respectively. Out of 35 participants, the intraoral membranous deposits and deposits on the pharyngeal mucosa developed in 17 (48.6%) and 10 persons (28.6%), respectively. The pharyngeal deposits developed in 58.8% of participants who developed intraoral deposits. All pathological specimens shared microscopic findings of various combinations of eosinophilic lamellar structure and a pale-basophilic amorphous substance. Immunohistochemically, both the 30 oral and the 16 pharyngeal specimens obtained from 17 participants were consistently positive for MUC7 but negative for MUC2. In conclusion, we clarified that the mucoid component of both oral and pharyngeal deposits comprised MUC7 salivary mucin, which revealed that both deposits originated from the oral cavity. This result strongly suggests that oral care is intimately related to oral and pharyngeal conditions.

Histopathological evaluation of oral membranous substance in bedridden elderly persons without oral intake in Japan.

OBJECTIVES: The aim of this study was to clarify by histopathological examination the origin of oral membranous substances deposited on the palate, tongue, buccal mucosa and teeth. BACKGROUND: Several investigators have reported membranous substances deposited in the mouths of bedridden elderly persons requiring nursing care without oral intake. However, the precise nature and origin of the substances are poorly understood. METHODS: Sixty-nine specimens were taken from the oral cavity of bedridden patients, that is, the palate, dorsum of the tongue, the cheek and teeth. Sections were stained with haematoxylin and eosin stain, alcian-blue and periodic acid-Schiff stain (AB-PAS) and antibodies for pankeratin (AE1AE3) and leukocyte common antigen (LCA). RESULTS: All specimens showed a film-like nature coloured from tan to white, accompanied by a mucous substance. Histologically, specimens of all sites had a similar feature of the combination of basophilic amorphous and eosinophilic lamellar features. The basophilic substance was positive for AB-PAS, and PAS-positive glycogen granules were also noted in the lamellar structure. Immunochemistry revealed various degrees of pankeratin positive substance and LCA-positive inflammatory cell infiltration. CONCLUSION: The oral membranous substance was composed of keratin and mucin with inflammation. These results suggest that the deposition of the oral membranous substance is a pathological condition or oral mucositis caused by dry mouth.

Phenotypic alteration of basal cells in oral lichen planus; switching keratin 19 and desmoglein 1 expression.

In oral lichen planus, extracellular matrix and basal cells are damaged by T-lymphocytes. As a consequence, changes in expression of collagen fibers within the connective tissue and cytoskeletons of the epithelial tissue can be observed. With the goal of examining the characteristic changes undergone by basal cells as a consequence of T-lymphocytes damage in oral lichen planus, we investigated protein expression in the epithelial-connective junction. We selected 20 cases of oral lichen planus and 5 control samples of buccal mucosa. Subsequently, we divided the oral lichen planus cases into thin and thick parts based on the mean values of epithelial thickness from the control samples, and counted the positive rate of collagen IV, keratin 19, desmoglein 1, and Ki-67. Collagen IV immune-reactivity partially disappeared or thickened in oral lichen planus. The keratin 19 positive rate in oral lichen planus cases was significantly lower than in the controls. Desmoglein 1 positive rate of the thick part was significantly higher compared to the thin part of oral lichen planus. Thus, modifications in basal cells with both reduced keratin 19 expression and alterations of desmoglein 1 expression suggest that in oral lichen planus, as a consequence of cell injury or regeneration in the interface area, there is a disappearance of the "true basal cell nature".

Factors affecting the formation of membranous substances in the palates of elderly persons requiring nursing care.

OBJECTIVE: To determine the causative factor behind the formation of membranous substances in the mouths of elderly patients requiring nursing care. BACKGROUND: Membranous substances are sometimes observed in the mouths of elderly persons requiring nursing care, and these can lead to bleeding, infection and asphyxiation. MATERIALS AND METHODS: In April 2007, samples were collected from 70 patients at C Hospital, Aichi Prefecture, Japan, who were 65 years or older (median age, 81.1 ± 7.7 years). Sixteen of the subjects were confirmed to have a membranous substance containing a keratin degeneration product that had been derived from stratified squamous epithelium. The samples were examined microscopically, and the presence of epithelial components was confirmed through immunohistochemical staining with anti-cytokeratin-1 antibodies. RESULTS: Decision tree analysis and logistic regression suggest that the leading contributors to the formation of the membranous substances were the method of ingesting nutrients, dryness of the tongue dorsum and open mouth. These three factors are related to elderly persons requiring nursing care with impaired oral cavity function, and it was suggested that dryness of the oral mucosa was the major factor behind the membrane formation.

Stress effect on bone remodeling and osseointegration on dental implant with novel nano/microporous surface functionalization.

The objective of this study was to investigate the stress distributions of a surface-treated dental implant and bone tissue under physiological loading. For ensuring success of dental implant treatment, one must examine the magnitude and location of the maximum stresses. Stress analysis models were constructed from computer tomography data. Although several studies have investigated finite element models of dental implants, none have used an implant model with a nanoporous layer in a biomimetic geometrical mandible model. The novel implant surface used in this study, comprised of a microlevel porous containing a nanolevel porous structure, was complex and it was difficult to present due to the limitation of computer efficiency. However, this complex geometry was simplified using a film, to further investigate stresses resulting from 0 nm, 50 nm, 500 nm, 5 µm, and 50 µm surface treatment thicknesses. Results indicated that the stresses transferred more uniformly in implants with nanoporous surface treatments, and that the stresses decreased with increasing layer thickness. Our study showed that this could be potentially beneficial for understanding the stress properties of surface-treated layers for dental implants.