Recent reviews of thyroid malignancies indicate an increasing incidenc
e with suggestions that incidence and regional variation in histologic
al types may be related to socioeconomic and environmental factors, We
studied 137 cases of thyroid cancer occurring in the University Colle
ge Hospital, Ibadan over a 20-year period (1965-1984), consisting of 4
5 males and 92 females, The ages ranged from 8-85 years with a mean ag
e of 40 years. Papillary carcinoma constituted 45.3% cases, whilst fol
licular carcinoma made up 44.5% with a frequency ratio of 1:1. Seven E
ases (5%) of medullary carcinoma were seen and these had a male/female
ratio of 1.3:1 with an average age of occurrence of 34 years, In cont
rast to previous studies from this environment, there is a suggestion
of an increasing trend in the incidence of papillary carcinoma in our
centre. The significance of changing socio-economic and environmental
factors in the region are highlighted.