[A case of metastatic rib tumor from thyroid cancer confirmed by the presence of thyroglobulin].

A 63-year-old female, with a chief complaint of right chest pain was referred to our hospital because of an abnormal right chest wall shadow on chest X-ray. A rib tumor was suspected based on her chest CT scan. Percutaneous needle biopsy yielded a diagnosis of well-differentiated adenocarcinoma. As metastatic rib tumor was suspected, the primary tumor was sought for. A thyroid gland nodule was recognized by ultrasonography, and the cytological diagnosis was class V. Immunohistological demonstration of the thyroglobulin studies of the rib tumor tissue revealed papillary and trabecular patterns of cell arrangement and the presence of thyroglobulin existence. Definitive diagnosis of metastatic rib tumor from thyroid cancer was established. Immunohistological examination is useful to confirm the diagnosis of metastatic cancer of thyroid origin.