Thyroid nodules in Graves' disease: implications in an endemically iodine deficient area

The presence of thyroid nodules with Graves' disease raises concern about co-existent thyroid malignancy. The objective of this study is to evaluate the risk of thyroid carcinoma and the need for surgical intervention in, patients with Graves' disease with co-existent nodules in an endemically iodine deficient area (IDA).

Retrospective study of 130 surgically managed patients of Graves' disease (1990-1999). Out of these 35 (26.9%) cases had palpable nodules. No patient had history of previous head and neck irradiation or radioiodine therapy. The clinico-pathological findings and follow-up of these cases were noted.

Mean age of patients with nodules was 40.2 +/- 9.5 years and male to female ratio was 1:2.2. The overall incidence of thyroid carcinoma in Graves' disease was 6.2% (8/130 cases), while the incidence, in cases having nodule with Graves' disease was 17.1% (6/35 cases). The median age of patients with carcinoma was 45 years (5 women and 1 man). Besides laboratory investigations for hyperthyroidism, preoperative investigations included fine needle aspiration cytology (FNAC) and thyroid scintigraphy in 29 and 25 cases respectively. Incidence of malignancy in palpable cold nodules was 20%. FNAC could not predict malignancy with certainty in any of these cases. Five patients had papillary thyroid carcinoma while one had follicular carcinoma. Median tumour diameter was 10 mm. Tumour was multi-centric in two cases while one case had metastases to cervical lymph node. In follow-up (median =5.5 years) one patient died of unrelated cause, while rest are alive with no evidence of disease.

Nodules are frequently associated with Graves' disease in IDA. Incidence of carcinoma is high in palpable cold nodule. We recommend early thyroidectomy in these cases.