Histopathological pattern of thyroid diseases in Zaria: A 10-year review

Context: Majority of the previous studies on thyroid diseases in Northern Nigeria focussed mainly on neoplastic lesions. The non-neoplastic lesions are more common and constitute more public health burdens. Aim: To determine the histopathological pattern of thyroid diseases in our region and compare our findings with similar studies in Nigeria and elsewhere. Settings and Design: This is a retrospective study carried out at the Department of Pathology, Ahmadu Bello University Teaching Hospital, Zaria, from January 2005 to December 2014 using specified criteria. Subjects and Methods: All cases of thyroid diseases diagnosed histologically within the study period had their histology reports as well as their haematoxylin and eosin-stained slides reviewed and analysed. Statistical Analysis: Statistical package for the social sciences (SPSS) software for windows version 20.0 (IBM SPSS Inc. Chicago, IL) was used. Results: There were 302 thyroid diseases diagnosed during the study period. Only 297 cases fulfilled the study inclusion criteria. There were 255 females and 42 males with a male-to-female ratio 1:6. Ages ranged from 4 months to 80 years, with peak age incidence between 31 and 50 years. Thyroglossal cysts accounted for 17 (5.7%) cases. Non-neoplastic diseases composed of colloid goitre, Graves' disease, Hashimoto thyroiditis and lymphocytic thyroiditis. They accounted for 214 (72.1%), 12 (4.0%), 3 (1.0%) and 1 (0.3%) cases, respectively. The neoplastic diseases comprised 36 (12.1%) adenoma cases and 14 (4.7%) carcinomas, with papillary carcinoma being the most common (71.4%) thyroid cancer. Conclusion: This study showed that thyroid diseases in Zaria had a female predominance with a peak age frequency between 30 and 50 years of age. The most common diseases were colloid goitre, follicular adenoma and papillary carcinoma. These findings are comparable with several studies on thyroid diseases in Nigeria and globally.