Papillary Thyroid Cancer Presenting as a Uterine Metastasis

The objective of this case is to report the highly unusual occurrence of uterine metastasis from a papillary thyroid cancer (PTC). PTC is rarely associated with distant metastases and typically spreads to bone or pulmonary tissue. In this case a 69-year-old female presented with post menopausal bleeding (PMB). She was otherwise well with no significant medical history or regular medications and reported no family history of thyroid disease. A subsequent endometrial polyp was identified as the cause of her PMB and removed. In addition as part of her clinical examination a goitre was noted and radiological imaging (including an ultrasound, magnetic resonance imaging of the neck and computer tomography of thorax, abdomen and pelvis) was performed and demonstrated a large thyroid mass which extended retrosternally and caused tracheal narrowing. The remainder of the imaging was unremarkable. The endometrial biopsy demonstrated morphological features of PTC. BRAF V600 mutation was not detected. A subsequent core biopsy of the mediastinal mass displayed morphological and immunohistochemical characteristic similar to that of the endometrial polyp. In combination this confirmed a diagnosis of primary papillary thyroid carcinoma. Surgical treatment included a total thyroidectomy, sternotomy and left neck dissection. Lymph node involvement was demonstrated at levels II-VI. Despite radioactive iodine and the use of tyrosine kinase inhibitors this lady died from complications of her disease. J Endocrinol Metab. 2019;9(4):113-116 doi: https://doi.org/10.14740/jem591