Nontraumatic Myositis Ossificans in a Muscle of Mastication

Myositis ossificans (MO) is an extraskeletal tumor-like lesion with bone formation, and is relatively rare in the head and neck region. We report herein a clinicopathological analysis of MO associated with a muscle of mastication. The patient was a 70-year-old Japanese woman who presented with a tumorous mass in the right parotid area and no history of trauma. The surgically excised tumorous lesion consisted of proliferating fibroblastic cells with no atypia in the central portion, and a formation of trabecular osteoid and/or bony tissue in the peripheral portion as the so-called “zonal phenomenon”. The final histological diagnosis was MO, and the lesion was located in the posterior belly of the digastric muscle on computer tomography. A review of the literature showed that many cases of MO predominantly affected the medial pterygoid and masseter muscle and showed a history of previous trauma. The present case represents a rare case of nontraumatic MO in the uncommon location of the posterior belly of the digastric muscle.

Histopathological, Immunohistochemical and Exfoliative Cytological Studies of Oral Verruciform Xanthoma

Verruciform xanthoma is a rare tumor-like lesion, predominantly affecting the oral mucosa. Although several studies of verruciform xanthoma have been reported, the characteristic features and pathogenesis have not been fully clarified. The purpose of the present study is to perform immunohistochemical analysis using markers of proliferative cell activity and cytokeratins, and to perform comparative analysis between cytological and histological features in order to clarify the characteristic features of verruciform xanthomas. Histological findings showed exophitic proliferation of stratified squamous epithelium and accumulation of foamy macrophages between epithelial processes. Immunohistochemically, accumulated foamy cells showed positive immuno-reactivity for CD68, and positive cells were also present in the epithelium. Expression of pancy-tokeratin was observed in most layers of the epithelium, whereas cytokeratin 13 was also detected in prickle cell layers. Positive reactivity for Ki-67 was observed in epithelial cell nuclei. Positive reactivity was largely distributed in basal and/or parabasal cell layers, and the positive cell rate was 20%. In addition, exfoliative cytological findings showed hyperkeratotic epithelial cells with picnosis, thus suggesting the characteristics of hyperplastic epithelium in verruciforma, although foamy cells were not observed in the cytological specimens. These results suggest that benign morphological characteristics with local cellular immune response of verruciform xanthoma may be evaluated based on immunohistochemical expression of cytokeratin and Ki-67, as well as exfoliative cytological findings.

Pemphigus vulgaris macroscopically and cytologically resembling oral squamous cell carcinoma

We describe the clinical, macroscopic, cytological, histopathological, immunohistochemical, serodiagnostic and aspects of pemphigus vulgaris (PV) in the oral gingiva that clinically mimicked oral squamous cell carcinoma (OSCC) in a 57-year-old Japanese man. He developed slight haphalgesia of the buccal gingiva around teeth numbers 18 and 19 2 years ago. A dentist diagnosed intractable ulcer, but the patient ignored the condition for about 2 years until a sharp pain in the gingiva worsened. He consulted an otolaryngologist, who referred the patient to our hospital under a cytological diagnosis of OSCC. An oral examination revealed several extensive painful erosions/ ulcers from the buccal and lingual gingiva around teeth numbers 18 to 21 to the distal alveolar mucosa of no. 18 and the buccal and lingual gingiva around tooth number 31. A presumptive diagnosis of PV with dysplastic changes was determined from cytological smears. The cytological Nikolsky test was positive. The diagnosis of PV was confirmed from clinical and histopathological findings of a biopsy specimen obtained from the perilesional site. Although the definitive diagnosis of PV required only 2 weeks after this patient presented at our hospital, 2 years had elapsed since the onset of oral lesions.

Morphometrical findings among dysplasias of oral, cervical and bronchial regions

The purpose of this study was to compare among dysplasia of oral, uterine cervix and bronchus. Using a computer cytomorphometry cell measurement program, the study was based on a retrospective review of smear cases diagnosed with dysplasia of oral, bronchial and uterine cervix, from 2002 to 2010. For 50 - 70 cells from each lesion, nuclear (N) and cytoplasm (C) variables were assessed: area (A), diameter (D), irregularity (I), stain brightness and granularity. NA and ND were highest in OSCC and higher according to dysplastic grading. By contrast, CA and CD were lowest in severe dysplasia. The significant difference of N/C ratio was observed among OSCC to inflammation, mild and moderate dysplasias (p < 0.05). The N/C ratios of mild and moderate dysplasias were equal. Brightness and granularity values of OSCC cases were significantly higher than those of another (p < 0.05). About the difference between mild to moderate dysplasias, it was the easiest to detect of the uterine cervix. All severe dysplasias among the 3 regions were easily identified morphometrically. The deficient in the difference between inflammation to mild dysplasia and mild to moderate dysplasia were obtained in the oral mucosal lesion. The results displayed a significant variation in cytomorphometrical values among the 3 regions. N/C values for uterine cervix and bronchus were well distinguished in comparison with oral dysplasias. Screening of mild and moderate dysplasias requires experience which carries out the comprehensive judgment of the color.

Palisaded encapsulated neuroma of the upper lip

Palisaded encapsulated neuroma (PEN;solitary circumscribed neuroma) is a benign and hyperplastic lesion consisting of Schwann cells. PEN of the lower lip was reported by Tomich and Moll [1] 35 years ago. However, the accumulation of the information about PEN which occurred in the oral mucosa was not enough. This article describes a case of a PEN on the upper lip of a 41-year-old woman. The lesion with 0.7 cm diameter was performed excisional biopsy. Histologically, the tumor was almost circumscribed by thin fibrous capsule, and consisted of diffusely and dense proliferation of the spindle shape cells arranged in interlacing fascicles. Focal suggestions of nuclear pal-isaded growth were indicated within the tumor. Immunohistochemicallly, the fascicles of tumor cells were positive for S-100 protein, and vimentin and negative for α-actin and GFAP. A few numbers of axons were demonstrated by anti-neurofilament antibody in this lesion. Therefore, the definitive diagnosis was PEN.

A clinico-pathological and cytological study of oral candidiasis

Candidiasis of the oral mucosa arises chiefly as a re- sult of infection with Candida albicans. Many clinico- pathological analyses of macroscopic findings have been described, although the clinical findings of oral candidiasis vary considerably and the conditions are complex. The present study analyzes the distribution, clinical, cytological and histological diagnoses of oral candidiasis, associated complex diseases and the di-agnostic value of cytology. The ratio of Candida in-fection was 28.9% among 1551 study participants. Females were infected significantly more often than men (p < 0.01) and the affected age range was 60 - 79 years (61.0%, p < 0.01). The predominantly affected areas were the tongue (48.3%, p < 0.01) and gingiva (20.0%, p < 0.01), and occurrence at multiple loci was seen in 43 (9.6%) patients. The typical clinical find- ings of oral candidiasis were ulcerative/erythematous lesions (33.2%, p < 0.01) and pseudomembranous candidiasis (31.6%, p < 0.01). A histopathological dia- gnosis of candidiasis based on biopsy specimens from 26 lesions in patients with Candida infection indicated by cytology was confirmed from cultures. The break- down of a cytological to a definite diagnosis was 6 positive (SCC 4, verrucous carcinoma 1, moderate to severe dysplasia 1), 6 suspected positive (mild dyspla- sia, 2;moderate to severe dysplasia, 2;papilloma, 1 and SCC, 1) and 14 negative (epulis, 3;papilloma, 3;granulation tissue, 2;fibrosis, 2 and others, 4). Exfo-liative cytology can easily judge the presence of Can-dida species, although experience is necessary for the presumptive diagnosis of an oral mucosal disease. The application of exfoliative cytology using the Pe- riodic acid-Schiff reaction is helpful for the earlier detection of oral candidiasis with various macrosco- pic findings.

Immunohistochemical Localization of Versican, Link Protein and Hyaluronic Acid Binding Protein in the Human Periodontal Ligament

The purpose of the present study was to histopathologically and immunohistochemically investigate the distribution of proteoglycans in human periodontal ligament (PDL). Specimens from osteotomy and tooth extraction having healthy PDL were studied. Histologically, PDL consisted of fibrous tissues, involving a compact arrangement area and edematous or myxoid area. Immuno-histochemically, versican binding region (12C5), versican link protein (8A4) and biotinylated hyaluronic acid binding protein (B-HABP) were distributed in PDL. In addition, positive immunore-activity for 12C5 and 8A4 was stronger in the compact arrangement area than in the edematous or myxoid area. Reactivity for B-HABP was stronger in the edematous or myxoid area than in the compact fibrous area. These results suggest that versican and link protein are associated with fibrous tissues, whereas hyaluronic acid is related to the formation of edematous and/or myxoid tissue in human PDL. These substances may play a role in periodontal homeostasis by protecting against mechanical stress.

Large stereoscopic LED display by use of parallax barrier of aperture grille type(Invited Paper)

We propose a large parallax barrier by use of aperture grille. Main advantages of using aperture grille include no reflection and no absorption in apertures, as well as wide viewing angle. These advantages are investigated with theoretical calculations and experiments by use of several kinds of LED panels, such as a fine-pitch LED panel and a 140-inch large LED panel. Limitations of viewing angle by parallax barrier are analyzed in conventional black stripes on a transparent substrate type and in aperture grille type. Experimental results straw use of aperture grille increases contrast and reduce reflection on the aperture surface.