Histopathologic patterns of thyroid diseases at a teaching hospital in Addis Ababa: A four-year retrospective study

Abstract

Background: Thyroid cancer is the most common malignant disease in the endocrine system and it is rapidly increasing in incidence. Its incidence is about three to four times higher among females than males worldwide, ranking the sixth most common malignancy diagnosed in women. Among the four major types of thyroid cancer, papillary thyroid cancer (PTC) consists of 85-90% of all thyroid cases, followed by follicular thyroid cancer (FTC) which accounts for 5-10% of cases. This study was designed to assess the pathologic patterns of thyroid disease at the Tikur Anbessa Specialized Teaching Hospital over four years focusing more on the incidence of thyroid cancer.

Methods: Ethical clearance was obtained from the institutional review board of the Addis Ababa University. A cross sectional study was conducted among patients operated for thyroid diseases from January 1, 2013 to December 30, 2016 in TASH. A retrospective data of 282 patients were included in this study. Descriptive statistics, using SPSS version 20, was done to determine the proportion of the thyroid lesions and to determine the pathologic patterns of the thyroid lesions.

Results: Of the 282 charts reviewed, 80.5% were females, 20.6% were between 25 to 34 years old, and the median duration of presentation was 4.5 years. Of the 187 patients for whom biopsy was done, 97 (34.3%) of cases were diagnosed with colloid goitre, 42 (14.9%) were diagnosed as papillary thyroid cancer, 41 (14.5%) diagnosed as follicular carcinoma. Two (2) patients were diagnosed as medullary carcinoma. Thyroid cancer was found to be common in females than males with F: M ratio, 2.5: 1.0. Males had a relative risk for thyroid cancer that is greater even though the disease is more common in females.

Conclusions: In this study thyroid cancer accounted for 30.1% of all patients operated for thyroid lesions with comparable incidence of PTC and FTC.