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A glandular odontogenic cyst (GOC), a rare type of cyst occurring in the jawbone, comprises about 0.2 % of all odontogenic cyst cases. Recurrence is likely, thus long-term follow-up examinations are necessary. The present patient was a 24-year-old Japanese female with a multilocular GOC that was extirpated following marsupialization. Two years after the initial extirpation, the GOC recurred and re-extirpation was performed, with no recurrence noted at two years after the second procedure. Although extirpation of a GOC after marsupialization can cause recurrence, it allows for preservation of teeth in the area of the lesion and maintenance of occlusion. The present case report includes a comparison of reports of GOC in Japan with those reported in other countries.

Cemento-ossifying fibroma (COF) is a clinicopatological variant of ossifying fibroma which is benign fibro-osseous neoplasm affecting jaw or cranial skeletons. It is also called central ossifying fibroma. COF is a slow-growing tumor and occurs exclusively in the tooth bearing areas of the jaws. This tumor particularly affects adult female and rarely occurs in children. Here we show a rare case of COF involving the anterior mandible in an 8-year-old girl. She was referred to our department with painless and hard swelling of the mandibular symphysis. Computed tomography (CT) showed that well circumscribed and mainly radiodense lesion with radiolucent areas expanded the inferior border of the mandible. The size of this lesion is 35 × 30 × 24 mm. Pathological diagnosis was COF. She had underwent two times of surgery for tumor enucleation through an intraoral approach, and after that, we removed bilateral central incisors with residual tumor around the roots. There has been no sign of recurrence 1 years after the last surgery. We have continued follow-up observation.

Spindle cell lipoma is a rare variety of lipoma that usually appears in subcutaneous tissue, for example, the posterior neck, shoulders, and back region, in middle-aged and older males. We reported a rare case of spindle cell lipoma of the floor of mouth. A 68-year-old man had a painless swelling of the floor of mouth. Clinical and image examination revealed that the mass was encapsulated, well-circumscribed, smooth-surfaced, and soft. Inside of the lesion was the same signal as adipose tissue, and the mass showed high signals at T1 and T2 weighted sequence in magnetic resonance imaging. However, the internal properties were non-uniform, and the vascular pattern was observed. Therefore, biopsy was performed before removal operation, and the mass was diagnosed as no malignancy. The encapsulated yellow mass was removed under general anesthesia. The histopathology showed that the well-demarcated mass was composed of mature adipocytes and spindle cells with bundles of collagen fibers. The size of mature adipocytes was uniform, and nuclear atypia was not observed. In immunohistochemical staining, the adipocytes were positive to S-100, and the spindle cells showed positive for CD34 and bcl-2 but S-100 negative. Based on the pathological features, the diagnosis was spindle cell lipoma. Differentiation of spindle cell lipoma includes solitary fibrous tumors, neurofibromas, subcutaneous fibrous malignancies, and well differentiated lipomas. S-100, CD34, and bcl-2 was able to differentiate these tumors and was very useful for the diagnosis of spindle cell lipoma. There were no signs of recurrence after 1-year follow up since the operation.

Regulatory T cells (Tregs) and tumour-associated macrophages (TAMs) contribute to the tumour microenvironment by inhibiting anti-tumour immune responses. This study was performed to investigate the roles of Tregs and TAMs in oral squamous cell carcinoma (OSCC) and oral epithelial precursor lesions (OEPL). The expression of Treg markers CD25 and FoxP3 and TAM markers CD163 and CD204 was investigated in 82 OSCC and 45 OEPL specimens, and their associations with clinicopathological parameters were analyzed. Correlations were found among CD25, FoxP3, CD163, and CD204 levels (P 0.001), and these targets were up-regulated in OSCC compared to OEPL (P 0.001). In OSCC, infiltration of Tregs and/or M2 TAMs was associated with sex and clinicopathological features, such as tumour size, nodal metastasis, tissue differentiation, stromal reaction, invasive behaviour, and invasive depth. In OEPL, CD25, FoxP3, CD163, and CD204 immunoreactivities were significantly associated with sex, postoperative recurrence, and cancerization to OSCC. This study is novel in showing that the infiltration of Tregs and M2 TAMs is significantly associated with the progression of premalignant lesions to OSCC. This suggests that these cells represent prognostic biomarkers for premalignant lesion progression and that immunotherapeutic approaches to control Treg/M2 TAM numbers could protect against progression to malignancy.

An association of the programmed cell death-1 (PD-1) and its ligand PD-L1 with various types of malignant tumors has been established. This study aimed to investigate the role of the PD-L1/PD-1 pathway in oral squamous cell carcinoma (OSCC) and oral epithelial precursor lesions (OEPL).We examined 106 OSCC and 79 OEPL specimens for PD-L1 and PD-1 expression by immunohistochemistry. The results were compared with clinicopathological features of OSCC patients.In OSCC and OEPL specimens, PD-L1 expression was detected predominantly in epithelial or carcinoma cells, whereas PD-1 expression was found mainly in infiltrating or stromal lymphocytes. Seventy-two OSCC (67.9%) and 21 OEPL (26.6%) specimens were positive for PD-L1, and 73 OSCC (68.9%) and 23 OEPL (29.2%) specimens were positive for PD-1. PD-L1 and PD-1 expression levels were significantly different between OEPL and OSCC specimens (P 0.001). There were significant positive correlations between PD-L1 and PD-1 expression in OEPL and OSCC specimens (P 0.001). PD-L1 and PD-1 immunoreactivity was significantly associated with tumor size (P 0.05). PD-L1 and PD-1 immunoreactivity in cases with advanced TNM staging was significantly higher than that in low staging cases (P 0.01). There were significant correlations between PD-L1 and PD-1 expression in OSCC specimens and pathological variables such as stromal lymphocytic reaction (P 0.05) and invasion depth (P 0.01).PD-L1 and PD-1 immunohistochemical status may be related to carcinogenesis, tumor progression, and prognosis in oral epithelial lesions. Agents targeting PD-1 and PD-L1 might be useful for OSCC treatment.

Objective To investigate roles of hypoxia-related proteins in odontogenic tumors, we analyzed the immunohistochemical expression of hypoxia-inducible factor-1α (HIF-1α) and carbonic anhydrase IX (CA IX) and compared with angiogenesis. Methods 10 dental follicles and 67 ameloblastomas were immunohistochemically examined with antibodies against HIF-1α, CA IX, and CD34. Results Immunohistochemical reactivity for HIF-1α and CA IX was detected in odontogenic epithelial cells, as well as in several macrophages and fibroblasts, in dental follicles and ameloblastomas. HIF-1α was positive in 8 of 10 dental follicles, 45 of 48 primary ameloblastomas, and all 19 recurrent ameloblastomas. Increased HIF-1α reactivity was often found in keratinizing cells in acanthomatous ameloblastomas. Immunoreactivity for CA IX was detected in all samples of dental follicles and primary and recurrent ameloblastomas. CA IX reactivity was significantly higher in ameloblastomas than in dental follicles, in solid ameloblastomas than in unicystic ameloblastomas, and in follicular ameloblastomas than in plexiform ameloblastomas. Acanthomatous ameloblastomas showed increased CA IX reactivity around keratinizing areas, while granular cell ameloblastomas showed increased reactivity in peripheral non-granular cells. Microvessel density (MVD) of CD34-positive capillaries in solid ameloblastomas was significantly higher than in unicystic ameloblastomas. MVD tended to be greater in follicular ameloblastomas than in plexiform ameloblastomas, in granular cell ameloblastomas than in other subtypes of ameloblastomas, and in mural unicystic ameloblastomas than in other types of unicystic ameloblastomas. Conclusions Our data suggest that hypoxia-related molecules and angiogenesis play a role in tumorigenesis, tissue structuring, cell differentiation, and prognosis of ameloblastomas in the intraosseous microenvironment.

Actinomycosis, a rare chronic granulomatous bacterial infection induced by Actinomyces species, colonizes the mouth, colon, and vagina. Although Actinomyces spp. are well-known oral commensals, actinomycosis is a rare oral infection. It is difficult to detect Actinomyces in biopsies, using histopathologic methods, or through examination of bacterial cultures; therefore, providing an accurate diagnosis is problematic. Recently, oral brush scraping cytology has been performed for the diagnosis of premalignant and malignant lesions, but it is difficult to determine the efficacy of this method based on the published reports, and whether it is a suitable tool for detecting Actinomyces infections in the general public. Here, we report a rare case of actinomycosis of the buccal mucosa in an 8-year-old boy that was successfully diagnosed by scraping cytology. He exhibited pain and swelling in the left buccal, and was admitted to our hospital for emergency care. Clinical examination revealed pyrexia, tachycardia, trismus, ingestion disorder, lethargy, and ulcer as well as having an indurated mass in the left buccal mucosa accompanied by strong pain. Following a clinical diagnosis of acute phlegmon of the left buccal mucosa, antibiotic and fluid therapy was performed. Because of detection of Actinomyces colonies at the ulcer surface using scraping cytology, we continued to administer long-term antibiotic therapy with penicillin for 2 months. The patient’s general condition was improved, and this was confirmed by laboratory results, and the trismus and painful nodular mass were successfully cured. The patient has shown no subsequent evidence of recurrence for 7 months of following treatment.

Objectives To study the role of epidermal growth factor receptor (EGFR) in oral squamous cell carcinoma (OSCC), protein expression, gene amplification, and mutations were analyzed in OSCC as well as leukoplakia. Immunoreactivity of Ki-67 and K- Ras gene mutations were simultaneously evaluated. Material and methods Eighty-two OSCC and 10 leukoplakia specimens were immunohistochemically examined with antibodies against EGFR and Ki-67. Amplification of EGFR was evaluated by chromogenic in situ hybridization (CISH). In 14 OSCC samples, EGFR exons 19, 21 and K- Ras exon 2 were analyzed by direct DNA sequencing. Results Immunohistochemical reactivity for EGFR and Ki-67 was detected in epithelial cells of leukoplakia and in carcinoma cells of OSCC. EGFR and Ki-67 immunoreactivity was significantly higher in OSCC than in leukoplakia. Leukoplakia showed no EGFR amplification, whereas OSCC exhibited low-level amplification in 19 cases and high-level amplification in 3 cases, respectively. OSCC cases with EGFR amplification showed slightly higher EGFR and Ki-67 immunoreactivity than those without amplification. In OSCC, EGFR immunoreactivity significantly correlated with the mode of invasion, invasion depth, as well as EGFR amplification significantly correlated with the degree of differentiation, mode of invasion, recurrence, and postoperative metastasis. Direct DNA sequencing of EGFR and K- Ras did not show any gene alterations in OSCC. Conclusion EGFR aberrations might contribute to carcinogenesis, invasion, metastasis as well as poor outcomes in OSCC. EGFR-targeting therapy with anti-EGFR monoclonal antibody agents may be beneficial in OSCC patients.

Calcium pyrophosphate dihydrate (CPPD) crystal deposition disease of the temporomandibular joint (TMJ) is rare. This article presents a 72-year-old man with CPPD deposition disease of TMJ. The patient's initial clinical presentation, diagnosis and treatment are discussed.

Platelets are reported to be causally involved in experimental hepatitis. Jo2, an agonistic anti-Fas antibody, induces hepatitis in mice. We examined the in vivo behaviors of platelets in mice injected with this antibody (analyzed by measuring 5-hydroxytryptamine, a constituent of platelets). We found that Jo2 induces platelet accumulation predominantly in the liver, and that this hepatic platelet accumulation (HPA) precedes the increases in hepatitis markers (alanine- and asparagine-aminotransferases [ALT and AST]). By electron microscopy, we detected entry of platelets into hepatocytes, and also evidence of apoptosis among hepatocytes. A caspases-3/6/7/8/10 inhibitor prevented the Jo2-induced HPA and hepatitis. In platelet-depleted mice, contrary to our expectations, the Jo2-induced hepatitis was not reduced, and actually the increase in AST was significantly augmented, although the survival time of mice given a lethal dose of Jo2 was significantly increased (nearly doubled). Interestingly, prior induction of HPA by a low dose of lipopolysaccharide markedly reduced Jo2-induced hepatitis. Jo2 also induced HPA and hepatitis in mice deficient in both IL-1 and TNFalpha, although Jo2 increased the blood level of TNFalpha in wild-type mice. These results suggest that in Jo2-induced hepatitis: (i) platelets accumulate predominantly in the liver as a result of hepatic lesions, and that this precedes the release of transaminases from hepatocytes, and (ii) IL-1 and TNFalpha are not essential for Jo2-hepatitis. We hypothesize that platelet accumulation in the liver may, contrary to our expectations, be protective when the hepatitis is local or not severe, but harmful when hepatitis is severe.

The Patched (PTC) gene is responsible for basal cell nevus syndrome (BCNS) accompanied by multiple odontogenic keratocysts (OKCs), and its product plays a role in the Sonic hedgehog (SHH) signaling pathway involving smoothened (SMO) and GLI-1. To clarify the role of SHH signaling in OKCs, the expression of SHH, PTC, SMO, and GLI-1 and mutations of PTC were examined in 18 sporadic, 4 BCNS-associated OKCs and 7 control gingivae. SHH, PTC, SMO, and GLI-1 were detected in all OKC and gingiva samples by reverse transcriptase-polymerase chain reaction (RT-PCR). Immunoreactivity for SHH and GLI-1 was markedly higher in epithelial components than in subepithelial cells, while immunoreactivity for PTC and SMO was similar in epithelial components and subepithelial cells in OKCs. The positive rate of PTC and SMO expression in subepithelial cells of OKCs was significantly higher than that in gingivae. The positive rate of GLI-1 expression in subepithelial cells of BCNS-associated OKCs was significantly higher than that in primary OKCs. These results suggest that the SHH signaling might be involved in the pathophysiologic nature of OKCs. While mutations of the PTC gene could not be detected in 4 BCNS-associated OKCs by direct DNA sequencing, 3 of 5 primary and 4 of 4 recurrent OKCs had several mutations of this gene. These results suggest that PTC mutations are probably related not only to BCNS-associated OKCs but also to sporadic OKCs.

A rare case of benign cementoblastoma involving multiple deciduous and permanent teeth is presented with a review of the literature. A 12-year-old boy was admitted for a swelling in the right maxillary premolar-molar region. A radiologic examination revealed a well-defined, round, radiopaque mass extending from the right maxillary first premolar to the second permanent molar. The tumor was removed with all associated teeth. A histologic examination of the surgical specimen revealed a well-circumscribed tumor composed of cementum-like tissue surrounded by a fibrous capsule. The tumor was attached to the roots of the second deciduous molar, first premolar, and the first and second permanent molars and embedded in the crown and root of the right maxillary second premolar, suggesting that the lesion had arisen from the second deciduous molar. There has been no recurrence of the lesion more than 18 months after the surgical procedure.

This paper reports a rare case of sebaceous adenoma on the right mandibular retromolar mucosa in a 73-year-old Japanese man, with a review of the English literature of sebaceous adenomas of salivary gland origin. A painless and yellowish polypoid lesion in the retromolar mucosa was histologically a relatively well-circumscribed neoplastic mass composed of well-differentiated sebaceous cells with cystic and duct-like structures, and was considered to be a true sebaceous gland neoplasm arising from the minor salivary gland tissue.

Purpose: In this study, we investigated the relationship between oxidative stress and apoptosis in synovial tissues in temporomandibular joint diseases (TMDs), including internal derangement (ID) and osteoarthritis (OA), comparing immunohistochemical, arthroscopic, and histologic findings. Materials and Methods: Synovial specimens obtained from patients with ID (31 patients), osteoarthritis (11 patients), and condylar fractures of the mandible (5 patients) during arthroscopy were examined immunohistochemically using antibodies against CD68, inducible nitric oxide synthase (iNOS), Fas, and single-stranded DNA (ssDNA). Results: CD68 and iNOS immunoreactivity were detected mainly in synovial lining cells and subintimal macrophages, and tended to increase with synovial hyperplasia. Fas and ssDNA immunoreactivity was detected mainly in synovial lining cells, and Fas-positive regions exhibited a number of ssDNA-positive cells. Fas expression was significantly greater in fractures than in OA, and ssDNA expression was significantly greater in OA than in ID. Fas expression was significantly greater in iNOS-positive versus iNOS-negative TMJs, and ssDNA expression tended to increase with iNOS expression. Conclusion: These immunohistochemical findings suggest that oxidative stress and apoptosis in synovial tissues are involved in the onset and progression of TMDs.

This article describes the unusual case of an intraoral pigmented naevus with pseudoepitheliomatous hyperplasia of the gingiva. A 62-year-old man presented with an almost coal-black pigmented and partly white, spotted, dome-shaped swelling on the lingual gingiva of the mandible. Histologically, the lesion consisted of clusters of round-shaped naevus cells containing melanin granules, reactive with both S-100 immunohistochemical stain and Masson-Fontana silver stain, and pseudoinvasive squamous nests, reactive with cytokeratin. The pathogenesis of the present lesion and problems encountered in its differential diagnosis are discussed.

An alveolar soft-part sarcoma (ASPS) occurring in the cheek is described, with a review of the literature. The subject was a 25-year-old woman who presented with a large swelling in the left cheek. The lesion, initially diagnosed as a benign tumor on radiographic and computed tomographic examinations, was surgically excised. Histopathological examination of the mass revealed a nest-like or organoid cellular arrangement as confirmed by three-dimensional computer graphic reconstruction. The cytoplasm of the large polygonal tumor cells contained abundant diastase-resistant, PAS-positive inclusions, ultrastructurally confirmed to be crystalloid materials. The tumor cells were immunoreactive for anti-myoglobin, sarcomeric actin, and neuron-specific enolase antibodies, suggesting a myogenic origin.