Warthin's tumour in Jamaica. Incidence, electron microscopy and immunoenzyme studies.

Warthin's tumour has traditionally had a strong male association, and has been said to be rare in Blacks. Current studies describe a new trend; a rise in females, strongly linked to cigarette smoking. The tumour has eosinophilic epithelial cells packed with distinctive mitochondria, and a lymphoid stroma. Immunological investigations have demonstrated polyclonal B cells, T cells and macrophages. Views differ as to whether B or T cells predominate. Between 1958 and 1989, the Jamaica Cancer Registry recorded 491 benign and malignant salivary gland tumours. There were 18 cases of Warthin's tumour (3.7%), with a male: female ratio of 5:1. The low proportion of females is similar to the trend for female lung cancer in Kingston & St. Andrew. A case of Warthin's tumour was studied by light and electron microscopy and immunoenzyme methods. The epithelial cells contained numerous mitochondria with stacked cristae, as previously described. Similar morphology occurs in oncocytic tumours; riboflavin-deficient rats and mice; rats given non-lethal doses of hypoglycin; dogs treated with annatto extracts; and hibernating or starving frogs. The mitochondrial changes may be an adaptive response. The immunoenzyme studies utilized newly available monoclonal antibodies: UCHL1, L26, 4KB5, MT1 and LN2. The reaction patterns indicate a distribution of B and T cells in a manner expected in a lymph node. The interaction between mitochondrial changes, adaptive metabolic pathways, the immune cells and tobacco raises some interesting questions.