Background: Distant metastasis of neoplasm to the thyroid gland represents an unusual clinical manifestation, especially in an individual without a prior history of malignancy. The most frequent site of origin is the renal system, followed by the respiratory system. Metastatic spread from the gastro-digestive tract is rare, and it mostly occurs from the colorectum.
Case Report: A 70-year-old woman presented with thyroid swelling and right vocal fold paralysis that have been going on for 6 months in the absence of upper digestive tract symptoms. Ultrasound-guided biopsy revealed metastatic adenocarcinoma. Its origin was confirmed through an endoscopic biopsy of an exophytic mass forming from the cardioesophageal junction. Computed tomography staging revealed an advanced-stage disease, with metastatic deposits over multiple organs. The patient was given palliative chemotherapy and supportive treatment. She succumbed to death at 1 month post-diagnosis.
Conclusion: Secondary thyroid malignancy represents a rare entity and should be contemplated as one of the differential diagnoses of a goiter. A thorough workout should be performed in atypical thyroid malignancy to avoid unnecessary thyroidectomies in widespread metastasis.