Thyroiditis and oncocytic carcinoma: incidental association? A case report

Several studies have reported an association between Hashimoto's disease and thyroid carcinoma although the cause/effect relationship is still controversial.

In this paper we report the case of a 38-year-old female who first presented with a clinical history of Hashimoto's thyroiditis. Ultrasound examination showed a diffuse thyroid irregularity more pronounced in the right lobe. FNAC (Fine Needle Aspiration Cytology) was performed in this area, and the cytological diagnosis was "Hashimoto's thyroiditis". The patient underwent clinical follow-up. Two years later, an ultrasound examination showed a nodular lump in the area previously aspirated. A new FNAC evidenced a Hurthle cell neoplasia. Therefore, the patient underwent surgery. The histological diagnosis was "Hurthle cell carcinoma".

In the present case, the clinical and ultrasound history suggest the development of a malignant lesion strictly related to thyroiditis, as previously reported by other studies on papillary carcinoma. A cause-effect relationship between chronic lymphocytic thyroiditis and oncocytic neoplasia is still a matter of controversy. Therefore, patients suffering from chronic thyroiditis require a careful follow-up and, in case of nodules development, FNAC is recommended.