A case of lung metastasis of papillary thyroid carcinoma presenting with tuberculous pleurisy / 대한내과학회지

ABSTRACT

Papillary thyroid carcinoma is the most prevalent type of thyroid cancer. Metastasis of this carcinoma commonly occurs in the lung and has been reported to present 5 to 30 years after the initial diagnosis of thyroid cancer. Pleural effusion can mask this metastatic spread. In patients with pleural effusion, laboratory measurement of the adenosine deaminase (ADA) level in the pleural fluid can be effective in identifying and ranking pulmonary metastasis in the differential diagnosis. A 70-year-old female patient visited our hospital with dyspnea. She presented with a considerable amount of pleural effusion. A pleural biopsy was performed and the Ziehl-Neelsen stains revealed a few acid-fast bacilli, but the ADA level in the pleural fluid was 2.4 IU/L. After drainage of the pleural effusions, we discovered pulmonary nodules by computed tomography (CT), which were later diagnosed through histologic examination as pulmonary metastasis from papillary thyroid carcinoma. We report this case.