Akinori Funayama

Emergence of keratin 17 vs. loss of keratin 13: Their reciprocal immunohistochemical profiles in oral carcinoma in situ

To evaluate differential expressions for keratin (K) subtypes 13 and 17 in oral borderline malignancies, we examined 67 surgical specimens of the oral mucosa for their immunohistochemical profiles. From those specimens, 173 foci of epithelial dysplasia, 152 foci of carcinoma in situ (CIS), and 82 foci of squamous cell carcinoma (SCC) were selected according to our diagnostic criteria, along with 20 areas of normal epithelia. In normal epithelia, there was no K17 positivity (0%), whereas definite K13 positivity (100%) was observed. The same tendencies were obtained in mild (undefined) and moderate (true) epithelial dysplasias (K17: 0%; K13: 100%). In contrast, all CIS (100%) had K17 positivities, while K13 positivities were lost in many of them (7%). Similar tendencies were confirmed in invasive SCC (K17: 100%, K13: 4%). Simultaneous immunopositivities for K17 and K13 were found only in SCC (7%) and CIS (4%) foci with distinct keratinization. These foci also showed K10 positivities, though K10 positive areas were not identical to K13 positive areas. The results indicate that expressions of K17 and K13 are reciprocal in oral epithelial lesions and that the K17 emergence is related to malignancies.

Enhanced Expression of Podoplanin in Oral Carcinomas in situ and Squamous Cell Carcinomas

Objective: Podoplanin, a known lymphatic endothelial cell marker, has been reported to be expressed in various types of cancer. To elucidate the expression of podoplanin in precancerous lesions, we examined the immunohistochemical profiles of podoplanin in oral squamous epithelial lesions. Method: We studied a total of 298 foci of squamous cell carcinoma (SCC), carcinoma in situ (CIS), epithelial dysplasia, and hyperplastic and/or normal epithelial lesions by immunohistochemistry using D2-40. Results: There was no positivity for podoplanin in normal or hyperplastic epithelia, while all of the CIS and SCC foci stained positive. Approximately one third of the mild dysplasia foci (10 of 36 foci, 28%) and 80% of moderate dysplasia foci (78/98) showed grade 1 positive reactions (positive only in the 1st layer). Grade 2 reactions (up to 4th layer) were seen in 4 of 98 moderate dysplasia foci (4%), 29 of 74 CIS foci (39%), and 3 of 30 SCC foci (10%). Grade 3 reactions (to more than 5th layer) were found in 35 (47%) CIS foci and 26 (87%) SCC foci. Conclusions: The relationship between the present histological categorization and podoplanin grade was statistically significant. D2-40 expression is considered to be related to the severity of oral precancerous lesions.

Changes in overnight arterial oxygen saturation after mandibular setback

Mandibular setback reduces space in the pharyngeal airway, and it has been suggested that it might induce sleep-disordered breathing. We report on its effects on space in the pharyngeal airway and respiratory function during sleep. We studied 78 patients (29 men and 49 women) in whom skeletal class III malocclusions had been corrected. The mean (range) age at operation was 24 (16-38) years and body mass index (BMI) 21.4 (16.1-30 .9)kg/m(2). Morphological changes were evaluated on lateral cephalograms taken three times: preoperatively, a few days postoperatively, and more than 6 months postoperatively. Overnight arterial oxygen saturation (SpO2) was measured by pulse oximetry 6 times: preoperatively, and on days 1, 3, 5, and 7, and 6 months postoperatively; oximetric indices were calculated. Those immediately after mandibular setback were significantly worse than those preoperatively, although they gradually improved. There were positive correlations between BMI and oximetric indices, and little association between changes in mandibular position and oximetric indices. There was no evidence of sleep-disordered breathing 6 months after mandibular setback because most patients adapt to the new environment for respiratory function during sleep. However, some (particularly obese) patients may develop sleep-disordered breathing just after mandibular setback. In such patients attention should be paid to respiratory function during sleep in the immediate postoperative period, and careful postoperative follow-up is needed.

Intraepithelially entrapped blood vessels in oral carcinoma in-situ

It can be difficult to make a certain diagnosis in case of an oral borderline malignant lesion on hematoxylin–eosin-stained sections only. Furthermore, assessment of surgical margins of borderline lesions is difficult with the naked eye. We set out to determine the topographical distribution of capillary blood vessels within the epithelial zone and to assess its use as an aid for histopathological diagnosis and a framework for clinical assessment of lesional margins using optical techniques, such as narrow-band imaging (NBI) endoscopy. Capillary blood vessels entrapped in the epithelial compartment, which we have designated as intraepithelially entrapped blood vessels (IEBVs), were examined for their frequency, location, and shape in normal mucosa, dysplasia, and carcinoma in-situ (CIS) of the tongue using immunohistochemistry for CD31 and type IV collagen. When counted per unit length of epithelial surface, IEBVs increased in number significantly in CIS (5.6 ± 2.8), which was two times more than in normal (1.9 ± 1.6) and dysplastic (2.4 ± 1.5) epithelia. In addition, IEBVs in CIS had compressed shapes with occasional obstruction or collapse with hemorrhage and were arranged perpendicular to and extending up to the epithelial surface. These characteristic IEBVs in CIS were considered to be generated by complex expansion of rete ridges due to carcinoma cell proliferation within the limited epithelial space determined by the basement membrane. The recognition of IEBVs was helpful in the differential diagnosis of oral CIS, and the present data provide a valuable frame of reference for detecting oral CIS areas using such NBI-based optical devices.

Inflammatory histopathogenesis of nasopalatine duct cyst: a clinicopathological study of 41 cases

OBJECTIVE The aim of this study is to characterize immunohistochemical profiles of lining epithelia of nasopalatine duct cyst (NPC) as well as to correlate those findings with their clinicopathological features to understand the histopathogenesis of NPC. MATERIALS AND METHODS Forty-one surgical specimens from NPC were examined for clinical profiles and expression of keratin-7, 13, MUC-1, and P63 by immunohistochemistry, compared to radicular cyst (RC) and maxillary sinusitis. RESULTS Nasopalatine duct cyst was clinically characterized by male predominant occurrence: 44% of the cases involved tooth roots, and 70% with inflammatory backgrounds. Lining epithelia of NPCs without daughter cysts were immunohistochemically distinguished into three layers: a keratin 7-positive (+) ciliated cell layer in the surface, a keratin-13+ middle layer, and a MUC-1+/P63+ lower half, indicating that they were not respiratory epithelia, and the same layering pattern was observed in RC. However, those immunolocalization patterns of the main cyst lining with daughter cyst were exactly the same as those of daughter cyst linings as well as duct epithelia of mucous glands. CONCLUSIONS Two possible histopathogenesis of NPC were clarified: one was inflammatory cyst like RC and the other was salivary duct cyst-like mucocele.

A simple technique for repositioning of the mandible by a surgical guide prepared using a three-dimensional model after segmental mandibulectomy

BackgroundMandibular reconstruction is performed after segmental mandibulectomy, and precise repositioning of the condylar head in the temporomandibular fossa is essential for maintaining preoperative occlusion.MethodsIn cases without involvement of soft tissue around the mandibular bone, the autopolymer resin in a soft state is pressed against the lower border of the mandible and buccal and lingual sides of the 3D model on the excised side. After hardening, it is shaved with a carbide bar to make the proximal and distal parts parallel to the resected surface in order to determine the direction of mandibular resection. On the other hand, in cases that require resection of soft tissue around the mandible such as cases of a malignant tumor, right and left mandibular rami of the 3D model are connected with the autopolymer resin to keep the preoperative position between proximal and distal segments before surgical simulation. The device is made to fit the lower border of the anterior mandible and the posterior border of the mandibular ramus. The device has a U-shaped handle so that adaptation of the device will not interfere with the soft tissue to be removed and has holes to be fixed on the mandible with screws.ResultsWe successfully performed the planned accurate segmental mandibulectomy and the precise repositioning of the condylar head by the device.ConclusionsThe present technique and device that we developed proved to be simple and useful for restoring the preoperative condylar head positioning in the temporomandibular fossa and the precise resection of the mandible.

Vertical distraction osteogenesis of a reconstructed mandible with a free vascularized fibula flap: a report of two cases

BackgroundThe free vascularized fibula flap presents many advantages such as sufficient length of the bony segment, good vascularization, better quality of the bone, and a long vascular pedicle, but it is also associated with some disadvantages with regard to prosthetic rehabilitation because of its limited height. Improvement in bone height is necessary for ideal dental implant treatment of reconstructed mandibles.Case presentationFor two squamous cell carcinoma patients, mandibular bone reconstruction was performed secondarily with the peroneal flap after tumor resection. Since the bone height was insufficient at the time of implant treatment, occlusion reconstruction by dental implant was performed after vertical distraction osteogenesis.ConclusionsVertical distraction osteogenesis is a suitable treatment option for alveolar ridge deficiency resulting from fibula transplantation for mandibular reconstruction following tumor surgery.