title: Colonic adenocarcinoma metastatic to thyroid Hürthle cell carcinoma presenting with airway obstruction.
abstract: Clinical presentation of a metastatic carcinoma to the thyroid gland is rare; it is more commonly reported in autopsy studies. Clinical presentation of malignant primary tumors to the thyroid is most common for renal, breast, and lung tumors that metastasize through a blood-borne route to the vascular thyroid gland. A 71-year-old man with a history of colon cancer that had been in remission for seven years had a long-standing thyroid goiter being followed elsewhere, with previous needle aspiration cytology consistent with a benign thyroid goiter. He presented with stridor, a 14 cm thyroid mass, and a larynx dramatically deviated to the contralateral side. Thyroidectomy resulted in return of the larynx to the midline with mobile vocal cords. Final pathologic examination indicated the rare phenomenon of tumor-to-tumor metastasis--a colon adenocarcinoma metastatic to a thyroid Hürthle cell carcinoma with focal areas of dedifferentiated anaplastic thyroid cancer. Colorectal carcinoma can remain asymptomatic for years. A thyroid mass in a patient previously diagnosed with a slow-growing malignancy (breast, kidney, colon) should be suspected of being a distant metastasis. Surgery may be indicated as palliative treatment.
authors.affiliation: Section of Otolaryngology-Head and Neck Surgery, Department of Surgery, Christiana Care Health System, Newark, Delaware, USA.
authors.forename: Robert L
authors.initials: RL
authors.lastname: Witt
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology*; D018249:Adenoma, Oxyphilic / Q000150:complications / Q000175:diagnosis / Q000556:secondary*; D000368:Aged; D000402:Airway Obstruction / Q000209:etiology*; D003110:Colonic Neoplasms / Q000473:pathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D013964:Thyroid Neoplasms / Q000150:complications / Q000175:diagnosis / Q000556:secondary*