Introduction: Correlation of papillary thyroid cancer and lymphocytic thyroiditis is well documented but the incidence of thyroid malignancies in Graves disease especially in the absence of nodular thyroid disease is considered to be uncommon.
Method: We conducted a retrospective audit of forty-four patients with established diagnosis of Graves thyrotoxicosis treated with total thyroidectomy from 2010-2013 (36 months), in a tertiary care centre. We studied the incidence rate of thyroid malignancy. In the study group 66.2% were females, with a mean age 35 compared to 33.85% males with mean age of 40. All patients had TSH< 0.01 mU/l on presentation, and six patients (13%) had associated thyroid eye disease.
Results: All patients had histological confirmation of Gravess thyrotoxicosis. Eight out of 44 (18%) patients (Male n=3; females n=5) were found to have incidental thyroid malignancy, all of which were confirmed papillary carcinoma with no extrathyroidal or lymph node invasion. patients (37.5%) had known nodular disease before surgery where diagnostic cytology was Thy 2, Thy5 and Thy3a respectively.
|Total number of patients||44|
|Incidence of malignancy||8||18|
|Malignancy in nodular disease||3||37.5|
|Malignancy in non nodular disease||5||62.5|
Conclusion: Incidental thyroid malignancy in patients known to have Graves thyrotoxicosis is now increasingly being reported1, our results support that. Most of them are low-risk papillary thyroid microcarcinoma without lymph node metastasis, lymphovascular and extrathyroidal invasion1. The role of autoimmune phenomena in the origin and clinical course of coexisting carcinomas is still controversial.2
1. Endocr Pathol. 2015 Mar;26(1):4853. doi: 10.1007/s12022-014-9343-6
2. Srp Arh Celok Lek. 2005 Oct;133 Suppl 1:746.