ELEVEN CASES OF BENIGN TUMOR OF THE EXTERNAL AUDITORY CANALAND ITS STATISTICAL INVESTIGATION IN JAPAN

Abstract

During a peroid of 20 years up to the end of 1966, 20 Patients with tumors of the external auditory canal visited the Department of Oto-rhino-laryngology of the Gunma Univeristy. Cases of them were benign tumors. They were : each 2 cases of cerminoma and naevus pigmentosus, and each 1 case of melanoma, chondroma, osteoma, haemangioma, fibroma, cyst and osteoma. The other 9 cases were malignant tumors (8 cases were squamous cell carcinoma and 1 case was carcinoma simplex). 130 cases of benign tumors of the external auditory canal which had been reported in Japan were discussed with our 11 cases. Despite pathohistological benignity, some clinically manifested malignant features. It is therefore necessary in their treatment to grasp exactly the essential nature of each tumor. Benign tumors of the external auditory canal are not so rare as generally discribed in textbooks. Often they seem to be misdiagnosed as otofuruncle. To diagnosis of them, careful observation and repeated pathohistological examinations are necessary.