Thyroid lymphoma.

We have reviewed the local experience of 15 cases of thyroid lymphoma with a view to documenting the epidemiology, presentation, management and prognostic factors governing outcome for this rare condition. All the patients were European despite the fact that 15 per cent of the local population is either Maori or Polynesian. The average age at presentation was 62 years and 13 of the 15 patients were women. The duration of symptoms was short: on average 9 months. Where feasible a definitive resection of the lesion was performed but this could only be performed in six of the 15 cases. The commonest histological type was non-Hodgkin's lymphoma which accounted for 14 of the 15 cases with the large cell variant being the most common (five cases). The mean period of follow-up was 3.3 years: only eight patients were alive and well at that time. The prognostic factors that influenced outcome were: (1) the histology of the lesion - large cell lymphoma carried a bad outlook; (2) whether the lesion could be totally resected or not - five out of six patients undergoing total resection remain alive and well; (3) the presence of pre-existing Hashimoto's thyroiditis was a favourable prognostic factor as only one patient without underlying Hashimoto's disease or positive antithyroid antibodies was alive at the end of the study; (4) male sex may also be an unfavourable prognostic factor as both men in the study died of disease 0.3 and 5 years after diagnosis.