Background: Lymph node metastasis from papillary thyroid cancer without detectable primary within the thyroid gland is extremely rare. We describe a case of a young woman with a cervical metastasis, without detectable orthotopic or ectopic thyroid focus.
Case report: A 30-year old woman with a history of adenocarcinoma of the ascending colon six years previously, presented at the 15th week of a normal second pregnancy, for management of subclinical Hashimotos thyroiditis. She had received thyroxine replacement during her first pregnancy 2 years earlier. She had a family history of colon cancer in her maternal grandmother and her mothers two cousins. On examination she had a palpable node at the right lateral compartment and her thyroid was not palpable. Ultrasound examination of the neck showed a small, mildly hypoechoic, heterogeneous gland and a well-defined, hypoechoic mass 30×15×13 mm, lateral to the right carotid artery at level IV. The mass was finally excised one year postpartum and was found to be a lymph node occupied extensively by follicular variant of papillary thyroid cancer. She subsequently underwent total thyroidectomy with central and right lateral node dissection without complications. Thorough histologic examination of the thyroid failed to reveal cancer, central compartment nodules were negative (0/17) and one more node harbored microscopic metastasis (1/18) on the right side. The contralateral nodes dissected were negative (0/9). MRI of the oropharynx, mediastinum, abdomen and pelvis and non-contrast CT of the lungs (scheduled for follow up of the bowel carcinoma) were normal. The patient has been referred for radioactive iodine treatment.
Conclusions: Papillary thyroid cancer presenting as a cervical mass in the absence of a thyroid primary, needs to be differentiated from ectopic thyroid cancer in the neck or elsewhere. A picocarcinoma or one that has spontaneously regressed cannot be excluded.
20 - 23 May 2017
European Society of Endocrinology