Isolated submandibular metastasis from a contralateral thyroid papillary microcarcinoma: an unusual case.

Papillary carcinoma is the most common form of thyroid cancer. It is a relatively indolent disease, which commonly remains clinically silent until its incidental histological diagnosis in surgical material or at autopsy. A tumour less than 10 mm in size is termed a papillary microcarcinoma. Papillary microcarcinoma may present with clinical symptoms, most commonly jugulodigastric and pretracheal lymphadenopathy with or without palpable thyroid nodules. Isolated submandibular metastases are rare. We present the case of a submandibular metastasis arising from a solitary 3 mm papillary microcarcinoma of the thyroid on the contralateral side in a 46-year-old woman. We describe the ultrasound and MRI characteristics of the submandibular mass. The ultrasound findings in particular were suggestive of a thyroid malignancy and prompted detailed examination of the thyroid gland. Clinical and radiological examination of the thyroid was normal. To the best of our knowledge, we present the first report of a papillary microcarcinoma of the thyroid presenting as a contralateral and isolated submandibular mass.