Incidental cancer in benign thyroid disease: An experience at the university hospital of the West Indies

Abstract

Introduction: There has been a marked increase in the incidence of thyroid cancer worldwide over recent decades. Some studies have suggested that the probability of finding malignancy is similar in both multinodular goitres and solitary nodules. There is a paucity of data regarding incidental thyroid cancer (ITC) in the West Indies literature. The aim of this study is to report our experience with ITC in order to examine the frequency of cancer in resected specimens for benign thyroid disease and to better characterize this entity. Methods: A retrospective chart review was performed on 753 patients who had a final histological diagnosis of benign thyroid disease after surgery between 2000 and 2009 at the University Hospital of the West Indies (UHWI). Twenty-one patients who had ITC had their charts analysed regarding the preoperative findings and histopathological diagnosis and this was compared to the preoperative and histological findings for 65 patients who had frank malignancy with no benign thyroid disease. The data were analysed using SPSS 22 software. Results: There were 753 patients with postoperative histopathological reports of multinodular goitre [MNG]. Twenty-one of the 753 patients [3 %] with MNG were found to have a malignancy. The mean [SD] age of presentation of incidental thyroid cancer was 48 [11.7] and the female to male ratio was nine to one. There were similar demographics for the 65 patients with frank thyroid carcinoma. There were no statistically significant preoperative clinical or diagnostic findings associated with incidental thyroid cancer. Eighteen [86%] incidental thyroid cancers were of the papillary type. Follicular carcinoma was seen in 9% and hurthle cell carcinoma accounted for only 5%. There were no cases of medullary or anaplastic carcinoma. While in the frank carcinomas, papillary accounted for 70%, follicular 9% and7% each for medullary and anaplastic carcinoma. Conclusion: The frequency (3%) of cancer in multinodular goitre in Jamaica is lower than other frequencies seen world-wide of both ITC and cancer arising from a solitary nodule. It is seen more commonly in the middle-aged females. Patients with MNG need a careful evaluation for the risk factors and require investigations such as an ultrasound and FNAC. Incidental thyroid cancers are most commonly of the papillary type which has a good prognosis.