We made some improvements on the in situ hybridization protocol for EB virus (EBV) detection so that many general laboratories in Japan are able to perform the procedure. Using FITC-labeled EBER-PNA probes (DAKO), we examined dilutions of several chemicals and the incubation temperature of the probes in tissue sections. We confirmed the accuracy and reproducibility of our protocol by applying PCR to detect EBV genomes within tissue sections. We applied the technique to 55 laboratory samples which were suspected to be infected with EBV, and eight negative control and successfully ended up with pathological diagnosis. Moreover, coupled with immunohistochemical detection of LMP-1, we could determine the type of EBV infection.

　　A 38-year-old woman was examined at our hospital because of cough, night sweats, and facial edema. Computed tomography of the chest revealed a large mass in the anterior mediastinum measuring 8.2×12.2 cm, with multiple nodules on both lungs. Bronchoscopy revealed multiple nodules parallel to the tracheal rings and obstruction of the anterior segmental bronchus of the right lung. The histopathological features were diagnostic of primary mediastinal large B-cell lymphoma. She underwent chemotherapy followed by radiation therapy to the mediastinal mass. After 8 months, she developed right cerebellar metastasis. Eventually, she received peripheral stem cell transplantation after 17 months.

　　Neuroendocrine small cell carcinoma is very rare in comparison with carcinoma of the cervix. In addition, it causes quite often metastasizes and has high recurrence rates. Furthermore, the mortality rate is high even among patients with early stage disease treated with common chemotherapy.　　We described a recurrent case of neuroendocrine small cell carcinoma, in which radiation therapy was delivered successfully but the disease relapsed during postoperative chemotherapy.

It has been reported that mucosal defects in the oral cavity caused by resection at a surgical site can be successfully repaired using a polyglycolic acid sheet, an absorbable artificial biomaterial, and fibrin glue spray. We report our experience of a case where bone surface coverage with a polyglycolic acid sheet and fibrin glue after exposure following resection of maxillary gingival leukoplakia led to a good outcome. The patient was a 64-year-old man with a keratotic white lesion on the right maxillary gingiva measuring 22 × 10 mm. He underwent resection of the lesion, which was diagnosed as maxillary gingival leukoplakia. The bone surface was exposed because of the operative extent and was covered with a polyglycolic acid sheet and fibrin glue. Wound healing progressed, and normal mucous membrane was seen at 5 weeks postoperatively. No relapse has occurred, and his progress is satisfactory.