Incidence of acoustic neuromas.

The annual incidence of diagnosed acoustic neuromas in Denmark during two 7-year periods from June 1976 to June 1990 was compared, collecting all operated and non-operated tumors from the entire country. During the first period 278 tumors were diagnosed with an annual incidence of 38 tumors or 7.8 tumors per million per year. During the second period the annual incidence rose to 48 tumors and 9.4 tumors per million per year. There was a significant decrease of extrameatal tumor size from 33 to 26 mm and diminishing of giant tumors.