Metastases to the thyroid: Two cases and a review of the literature

Background: Metastases to the thyroid gland are uncommon in clinical practice. However, the incidence of secondary thyroid tumors reached up to 24% in selected autopsy series. First Case Report: A metastasis to the thyroid gland was removed in a 54-year-old man with a large-cell anaplastic carcinoma of the left lung. Later, the patient was irradiated in the cervical region because of a thyroid recurrence. A complete remission was achieved. Eleven months later the patient died with a pulmonal progression and multiple brain metastases. Second Case Report: A metastasis of an unknown primary in the cerebellum of a 52-year-old man was removed. Progression of disease with a mediastinal tumor occurred 5 months after initial treatment. The patient died of multi-organ failure. Upon autopsy a small-cell lung carcinoma was diagnosed and a metastasis in the thyroid was found. Conclusion: Metastases to the thyroid gland are often a sign of an unfavorable clinical course. The most common primary sites of solid tumors are lung, breast, kidney, and the gastrointestinal tract. Lymphomas as systemic diseases have to be taken into consideration, too. Fast diagnosis and individual therapy can improve the quality of life and prolong survival.