Clinical and histological differences in anaplastic thyroid carcinoma

Objective: To report our experience in patients with anaplastic thyroid car cinoma and try to establish differences between cases in which the histolog ical study showed that there was an associated thyroid carcinoma and those: that were strictly anaplastic or pure. Design: Retrospective study. Setting: University hospital, Spain. Subjects: 14 patients with anaplastic thyroid cancer treated over a period of 26 years; 7 presented with associated thyroid rumours and 7 were pure. Main outcome measures: Clinical data (age, sex, symptoms), treatment, histo logical study (associated thyroid disease, spread, involved lymph nodes) an d follow-up. Results: 13 of the 14 tumours had spread locally. 5 patients were treated b y total thyroidectomy, 3 subtotal thyroidectomy, 5 excision of the tumour, and 1 patient had a biopsy done. There were associated thyroid tumours in 7 cases: 2 follicular, 2 tall cell papillary, 1 solid papillary, 1 medullary and 1 Hurthle cell tumour. 12 patients died. Another 2 are still alive hav ing survived 61 and 70 months respectively, both with associated anaplastic cancers (follicular and solid). The mean survival was 14 months (24 for as sociated anaplastic carcinoma and 4 for pure anaplastic carcinoma). Conclusion: There is a subgroup of anaplastic cancers in which a better dif ferentiated thyroid carcinoma coexists with the anaplastic carcinoma. The p rognosis in this subgroup is better than that for primary pure anaplastic c arcinoma.