There is controversy whether idiopathic mid-line destructive disease remains a valid entity, some authors considering that such cases are unrecognized malignant lymphoma or Wegener's disease. A case is presented in which numerous nasal biopsies over several years failed to show evidence of either lymphoma or Wegener's disease. Molecular genetic analysis of archival tissue did not demonstrate a monoclonal lymphoid population. It is proposed that idiopathic mid-line destructive disease remains a valid description in a small number of cases.

The expression of proliferating cell nuclear antigen in paraffin sections from 154 cases of laryngeal squamous cell carcinoma were examined. There was significant difference in PCNA expression between the control group and cancer patients (p<0.001). The mean score of PCNA was higher in patients with poor prognosis than in patients with satisfactory outcome after treatment (p<0.05). There was no significant correlation between the PCNA count and the patient's age and sex, T and N stage and site of the tumour.

Univariate analysis revealed that the PCNA score correlated with the patients' survival rates. In multivariate analysis the prognostic value of PCNA was on the statistical borderline (p = 0.049). In our study clinical features like N and T status had a more important influence on survival rate. Nevertheless it appears that the immunohistological examination of PCNA in paraffin section could be a complementary prognostic tool for laryngeal carcinoma. PCNA expression may also be a valuable tool for differentiating malignant from benign laryngeal epithelium.