The frequency of carcinoma in solitary thyroid nodules and in multinodular goitres

A retrospective study of all patients with goitre seen from 1988 to 1992 inclusive at the Muhimbili Medical Centre, Dar es Salaam was made to determine the frequency of malignancy in patients with solitary non-toxic thyroid nodule (STN) and in those with multinodular goitre (MNG). There were 60 cases of STN and 178 with MNG. Nodular goitre was found to be predominantly a disease of females with sex ratios of M:F;1:7 for the STN group and of M:F;1:13 in the MNG group. The final diagnosis in all cases was made by histology which found malignancy in 10% of STN and in 5% of MNG patients, a difference which was not statistically significant. Patients in the 20-29 years age group with STN appeared to have an increased risk of malignancy when compared with the MNG group. No cause for this was discovered. The predominant malignancy in the STN group of patients was papillary carcinoma, while that in the MNG group was follicular carcinoma. Key Words: thyroid, malignancy, solitary nodule, multinodular goitr