A Rare Case of Metastatic Papillary Thyroid Carcinoma Presenting as an Invasive Orbital Mass

A 53-year-old female presented with a growing left orbital mass for a year. On examination, there was a large firm and tender mass involving the entire left orbit and forehead with gross displacement of the left globe (Panel A). CT Orbits demonstrated a 4.3 × 5.2 × 5 cm heterogeneously enhancing mass with central necrosis centered in the left frontal calvarium with intracranial extension into the left frontal lobe and extension into the left extraconal orbit, displacing the optic nerve and deforming the left globe (Panel B). The mass was biopsied using a superior eyelid crease approach. Intraoperatively, the tumor tissue was found to be highly friable and vascular. Tumor histopathology was characterized by papillary fronds lined by neoplastic cells and nuclear overlapping (Panel C, 20×, arrows) and follicular-like structures with nuclear crowding and chromatin clearing (Panel D, 40×, arrows). Tumor cells revealed positive expression of thyroid transcription factor 1 (Panel C, inset) and thyroglobulin (Panel D, inset). Subsequent workup determined that the patient had metastatic papillary thyroid cancer to the vertebrae and lung, in addition to the left orbitofrontal region. Due to a poor social situation, mental health constraints, and advanced disease, she was not a good candidate for systemic cancer treatment or surgical resection. Papillary thyroid carcinoma is the most common thyroid cancer with a low rate of distant metastasis in approximately 2%–5% of patients. The orbit is a rare site of thyroid cancer metastasis, with less than 5 cases previously reported in the literature. Written informed consent was obtained from the patient for publication of this study.FIG