Neurilemmoma of the Vagus Nerve in the Poststyloid Parapharyngeal Space.

We report a large vagal neurilemmoma in the poststyloid compartment of the parapharyngeal space. A 52-year-old man was referred to our hospital with a feeling of discomfort in the left upper neck. Computed tomography showed a 30mm x 30mm x 40mm mass with inhomogeneous internal enhancement in the left carotid space. Magnetic resonance imaging revealed a 30mm × 30mm × 40mm heterogeneous mass in the area of the bifurcation of the common carotid artery. We gave a provisional diagnosis of neurilemmoma or vagal paraganglioma in the parapharyngeal space preoperatively based on the results of physical examination and imaging. We selected a transcervical-transmandibular approach. Under general anaesthesia, a tumour originating from the vagus nerve was completely extirpated while protecting the internal and external carotid arteries. Although mild postvagotomy dysphagia and hoarseness were seem for 6 months postoperatively, symptoms resolved and the patient showed a satisfactory course without recurrence after 10 years. Histological examination of the excised specimen showed antoni A and antoni B pattern. Positive immunoreactivity for S-100 protein was identified, but negative results were obtained for neuron-specific enolase, chromogranin and neurofilament. The tumour was diagnosed as neurilemmoma of the vagus nerve.

A Case of Verruciform Xanthoma Arising in the Tongue.

Verruciform Xanthoma (VX) is a rare lesion of the oral cavity. Histologically, it is characterized by papillary or verrucous proliferation of squamous epithelium and numerous foam cells. VX arising in the tongue is comparatively rare, as most cases of VX in oral cavity occur in gingiva. A 65-year-old woman was referred to our clinic with a mass on the left side of the tongue. The lesion was yellowish, and its surface was granulated. The patient had neither tenderness nor any symptoms. The lesion was clinically diagnosed to be a benign tumor, and hence, biopsy was performed, according to which it was diagnosed as hyperparakeratosis. Based on this diagnosis, the tumor was excised under general anesthesia. Histopathologically, the tumor consisted of stratified squamous epithelium with parakeratosis and elongated rete ridges. Aggregation of foam cells was observed between and under the rete ridges. From these features, a diagnosis of VX was made. The patient has had no local recurrence as of three years post-operatively.

Outcome following lingual nerve repair with vein graft cuff: a preliminary report.

PURPOSE: The object of this study was to assess the effects of an inside-out vein graft as a cuff after direct suture on human lingual nerve regeneration and recovery after iatrogenic lingual nerve injury. PATIENTS AND METHODS: Ten patients with unilateral lingual nerve anesthesia as a complication of iatrogenic injury after third molar extraction underwent microneurosurgical procedures for the injured lingual nerve under general anesthesia. The patients were randomized into 2 groups. In group A, after removing the neuromas and peripheral scars surrounding the torn nerves, the 2 nerve ends were sutured without tension. In group B, after the same procedure, including the same suturing procedure, an inside-out vein graft was placed as a cuff after the direct suture. Each group was followed at least once every 6 months for 1 year after the procedure. Postoperative outcomes were evaluated using the Pogrel criteria, the Sunderland grade, and the British Medical Research Council Scale (MRCS). RESULTS: There were no particular differences between groups A and B at 6 and 12 months after the operation. However, based on the MRCS criteria, there was a clearly better result in group B than in group A at 6 and 12 months after the operation, and the recovery of gustatory sensation tended to be better in group B than in group A 1 year after the operation. CONCLUSION: This inside-out vein graft as a cuff after direct suturing may facilitate faster lingual nerve regeneration than the traditional direct suture approach. The inside-out vein graft as a cuff may provide the advantages of preventing axonal escape at the suture lines, minimizing nerve entrapment, and preventing neuroma formation in the space between the sutured nerves.

Expression of ADAMTS-5 in deformed human temporomandibular joint discs.

OBJECTIVE: To study the expression of a disintegrin and metalloproteinase with thrombospondin motifs 5 (ADAMTS-5) in tissue samples of deformed human temporomandibular joint (TMJ) discs and cells obtained from the discs. MATERIALS AND METHODS: Eleven adult human TMJ discs (nine diseased discs and two normal discs) were used in this study. The nine diseased discs were obtained from nine patients with internal derangement (ID) and osteoarthritis (OA) in the TMJ. These patients all had anteriorly displaced discs and deformed mandibular condyles, making conservative therapy impossible. The tissues were immunohistochemically stained using ADAMTS-5 antibodies. In addition, an articular disc cell line from one case was established by collagenase treatment. The subcultured cells under both normal and hypoxic conditions (O2: 2%) were incubated for 3, 6, 12 and 24 h after addition of interleukin-1beta (IL-1beta) (1 ng/mL). Subsequently, the expression of ADAMTS-5 was examined using reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: The control group showed negative reactions on immunohistochemical staining. The discs extracted from cases with ID and OA presented positive reactions for ADAMTS-5. The expression of ADAMTS-5 mRNA increased under both normoxia and hypoxia with the addition of IL-1beta, and the peak was observed after 3 h. CONCLUSION: These results suggest that ADAMTS-5 is related to deformation and destruction of human TMJ discs affected by ID and OA.

EGFR inhibitor enhances cisplatin sensitivity of oral squamous cell carcinoma cell lines.

Epidermal growth factor receptor (EGFR) is involved in multiple aspects of cancer cell biology. EGFR has already been identified as an important target for cancer therapy, with various kinds of EGFR inhibitors currently used in treatment of several human cancers. Recently, EGFR and its downstream signaling pathways were identified as being associated with cisplatin sensitivity. In addition, EGFR inhibitors have shown significant promise for patients who failed cisplatin-based therapy. In this study, we investigated whether treatment with an EGFR inhibitor improves cisplatin sensitivity in oral squamous cell carcinoma (OSCC) cell lines. The effects of a combination of AG1478, a specific EGFR tyrosine kinase inhibitor, with cisplatin were evaluated in cultured OSCC cell lines and cisplatin-resistant sublines. Higher expression of EGFR and p-EGFR was found in the two cisplatin-resistant cell lines compared with the corresponding parental cell lines. In addition, augmented inhibition of OSCC cell growth by the combination of AG1478 with cisplatin was found in both cell lines. These results suggest that the combination of an EGFR inhibitor and cisplatin may be useful as a rational strategy for the treatment of patients with oral cancer with acquired cisplatin resistance.