Using Ki-67, a monoclonal antibody, the proliferating capacity of 15 salivary gland tumours, including nine pleomorphic adenomas, four adenoid cystic carcinomas, one mucoepidermoid carcinoma and one acinic cell carcinoma was determined immunohistochemically, using normal salivary gland tissue as a control. The frequency of Ki-67 positive cells was 4.7 per cent in the normal salivary gland and one per cent in pleomorphic adenomas, whereas the average frequency in malignant tumours was 18.3 per cent. Among adenoid cystic carcinomas, the frequency was related to the morphological type; the solid sub-type had the highest frequency of Ki-67-positive cells. As this sub-type is recognized as the most aggressive of these tumours, this technique has the potential of providing an early indication of the clinical behaviour of a tumour.

The incidence of histologic otosclerosis among Japanese seemed to be almost the same as that among Caucasians. Three reasons why clinical otosclerosis was not as prevalent among Japanese as among Caucasians are suggested: low incidence of involvement of foci anterior to the oval window, low activity, and small lesion without involvement of the footplate and/or membranous labyrinth of the inner ear.

In the period 1983 to 1985, 66 patients presented to six Japanese university hospitals with squamous cell carcinoma of the maxillary sinus. Using self-administered questionnaires, a case-control study was conducted to examine history of nasal diseases, occupational exposures, and other possible risk factors for this disease. For each patient, two controls were selected from the general population, matched to the patient by sex, age (+/- 5 years), and district of residence. A history of chronic sinusitis was associated with a 2.3-fold increase in risk (p = 0.05). A high relative risk was also observed in males with an occupational history of woodworking or joinery, particularly when these jobs involved sanding or lathing practices (RR = 7.5, p = 0.02). No association between cigarette smoking and maxillary sinus cancer was observed in this study and no evidence was found that indoor air pollution in the home is involved in cancer development.

This study aimed to demonstrate the temporal bone histopathology of two cases of Wegener's granulomatosis in which the initial symptoms were profound hearing loss and facial nerve palsy respectively.The first case, a woman of 44, suffered profound hearing loss which was remarkably improved by steroid and cyclophosphamide treatment for a time, and which seemed to be caused by invasion from granulation tissue filled in the tympanic cavity. The second case was a 61-year-old woman presenting with the facial nerve palsy. The bony canal of the horizontal portion of the facial nerve was destroyed due to granulation tissue which filled in the tympanic cavity, and granulomatous involvement was observed in the facial nerve. Wegener's granulomatosis can involve the middle ear and/or inner ear, causing hearing loss of conductive, mixed or sensorineural type. Pathogenesis of facial nerve palsy seems to be related to Wegener's granulomatous involvement of facial nerve, because the facial nerve palsy also resolved by using steroid and cyclophosphamide.

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