A study of immunoglobulin-containing and other cells in ovine aural squamous cell carcinoma

The peroxidase-antiperoxidase method was used to quantify immunoglobulin (Ig)-containing cells at the host-tumour interface in ovine aural squamous cell carcinoma lesions at various stages of development. IgM-containing cells were never observed; only scattered, but strongly staining, IgA-containing cells were present. IgG-containing cells predominated; their prevalence increased from 0.17 +/- 0.34 cells per high power field (hpf; mean +/- standard deviation) in precursor lesions to a maximum of 13.6 +/- 2.6 cells per hpf in overt tumours which had not metastasized. Their prevalence in overt tumours which had metastasized was 4.6 +/- 3.9 cells per hpf. Quantitation of pyroninophils in sections stained by the methyl green-pyronin method showed a greater prevalence of plasma cells than IgG-containing cells, but a similar pattern of change was apparent. Mast cells were most prevalent in early stages, but no significant change in eosinophil numbers was observed.