Prevalence of thyroid cancer among thyroid swelling in Jimma University Medical Center, South West Ethiopia: A five-year retrospective study

Thyroid cancer is the most common endocrine malignancies. It is postulated that goiter is a precursor lesion to the development of thyroid cancer. The worldwide prevalence of goiter in the general population is estimated at 4 to 7%. The objective of the study was to assess the burden of thyroid cancer among patients who visited Jimma University Medical Center (JUMC) with thyroid swelling over the past 5 years. The record of patients who have undergone Fine Needle Aspiration Cytology (FNAC) over the past five years from September 2012-July 2017 was taken as the source population and the patients who underwent FNAC for a thyroid swelling were taken as the study population. The information was collected by the principal investigator and a trained data collector using a structured data collecting guide. Data was compiled and analyzed using IBM SPSS version 22 software and presented using tables, graphs and figures. A total of 2008 thyroid cases which underwent FNAC from September 2012 to July 2017 were collected. Of these, 378 (18.9%) were male and 1626 (81.1%) female. It was observed that the highest prevalence of thyroid swelling cases occurred in the age group of 20 to 30 years with 577 (29.2%) of the participants. The most common thyroid lesion that was found was goiter accounting for 85.4% (1715/2008) of all thyroid swellings in patients that underwent FNAC during the study period. And the most common malignancy that was found was papillary carcinoma (PTC) accounting for 49.3% of malignant lesions. As known, the highest prevalence of carcinoma was found in 2016/17, with 25 (5.8%) and lowest in 2012/2013 with 8 (3.7%). Based on this study, although thyroid swelling is quite a common problem in and around Jimma, the prevalence of thyroid cancer is quite low. And the leading type of malignancy is papillary thyroid carcinoma. Age was found to have a statistically significant association with thyroid malignancy. And there is an increasing incidence of thyroid malignancy over the past 5 years.