Incidental finding of occult carcinoma in histology in total thyroidectomy for benign thyroid disease

Abstract

OBJECTIVES: The incidence of occult carcinoma of thyroid varies from 1%-10% in the literature. These unexpected cancers do not show any pre or intra-operative indication of malignancy. Total thyroidectomy in benign thyroid disease is receiving wider acceptance. If a lesser surgery is performed and an occult carcinoma is detected a difficult therapeutic dilemma ensues. This study presents the incidence and clinical presentation of occult carcinomas in a series of total thyroidectomies performed for benign disease. METHODS: Analysis was performed on 55 patients who have undergone total thyroidectomy for benign diseases. Surgeries were performed at the University Surgical Unit of North Colombo Teaching Hospital by a single surgeon from January 2000 to August 2005. Clinical manifestations, surgical details and histological findings were obtained from the patients' records. RESULTS: Five cases of occult carcinomas were discovered with an incidence of 9.1%. Histology confirmed 2 papilary, 2 medullary and 1 follicular carcinomas. Mean age was 52.0 (SD ±13.3) years and 80% were females. Majority (80%) presented with multinodular goiters; 60% were euthyroid and 40% were hyperthyroid. Fine needle aspiration cytology confirmed benign aetiology in all. None of these patients developed transient or permanent complications following total thyroidectomy. CONCLUSIONS: Incidence of occult thyroid carcinoma is 9.1% in this series. None of the patients had problems following total thyroidectomy. The policy of performing total thyroidectomy in benign disease appears to be beneficial as it obviate the need for further surgery if an occult carcinoma is found.