Prevalence of differentiated thyroid cancer in 810 cases of surgically treated goiter in Yemen

BACKGROUND: In 1990, the World Health Organization (WHO) suggested that severe iodine deficiency exists in Yemen. Therefore, we looked at the prevalence of differentiated thyroid goiter in 810 cases consecutively treated by surgery for goiter. METHODS: This was a retrospective study of 810 surgically operated cases of goiter over a 5-year period (1999–2003). All cases were evaluated on H&E stained sections from embedded, 10% buffered formalin fixed tissue blocks. Special stains and immunohistochemical analysis were done in Yemen and abroad. Most patients were older than 20 years of age and were from the high altitude areas (2000 to 2600 meters above sea level), where iodine deficiency disorders (IDD) are well documented. RESULTS: In the 810 cases, 729 (90%) were females and the remaining 81 (10%) were males, with female-to-male ratio of 9:1. Differentiated thyroid cancer (DTC) was found in 170 (21%) cases, including 148 (86.4%) females and 22 (13.6%) males. Nearly 60% of the cases were in the age group of 21–40 years. Papillary carcinoma was the most common type of DTC (164 cases, 96.5%). CONCLUSIONS: In a Yemeni population, which has a high prevalence of iodine deficiency, 21% of patients operated on for nodular goiter without pre-operative fine needle aspiration biopsy had thyroid cancer, mostly of the papillary type. In this study, males and elderly patients with goiter had a higher chance of having malignancy.