The demonstration of cartilaginous involvement in laryngeal carcinoma by computerized tomography.

Thirty-six patients with laryngeal carcinoma were investigated by computerized tomography (CT). In 8 patients invasion of cartilage was shown at subsequent pathological examination of the excised larynges. In all there were 14 areas of cartilage involvement, 11 of which could be diagnosed on retrospective examination of the CT scans. Involvement of tumour was shown either as areas of decreased density (chondrolysis) or areas of local increased density (chondrosclerosis) due to cartilage ossification. False positive and false negative evidence of cartilage involvement was recorded in the series, but the accuracy of diagnosis in positive terms was approximately 79%. Histological evidence is put forward that the presence of carcinoma in relation to the cartilage produces perichondritis, which enhances ossification and the latter process may then in itself facilitate invasion by the tumour. Previous radiotherapy may also be a factor in the causation of the perichondritis and ossification.