Morphological observations of immunobiology of laryngeal cancer. Evaluation of the defensive activity of immunocompetent cells present in tumour stroma.

A series of 104 patients with squamous cell carcinoma of the larynx was studied with regard to tumour-host interaction. Prognostic evaluation was based upon histologic grading and morphological evidence of host immune response, judged by the presence and degree of lymphocyte and plasma cell infiltration in tumour stroma. Histologic grade and lymphoplasma-cellular infiltration do correlate with the 5-year survival. The immune response, however, seems to be a favourable prognostic sign only for well differentiated tumours; in our series, all poorly differentiated neoplasms showed minimal or no cellular response. The survival rate increases with the increasing intensity of cellular response within each class of tumour cell differentiation. Small lymphocytes are the basic elements of cell-mediated immune response. After tumour antigenic stimulation they change into immunoblasts which in turn would produce "committed" lymphocytes which would recognize and destroy tumour cells.