Papillary Thyroid Carcinoma Mimicking Miliary Tuberculosis in a 14-year-old Boy

A 14-year-old boy was referred to our hospital because of the incidental finding of numerous nodular lesions in both lungs. He had been hospitalised at a local orthopaedic department for pin removal after fixation for ankle fracture. On chest radiography for regular check-up prior to the operation, multiple nodular lesions were observed. Physical examination revealed normal results. Chest computed tomography ( CT) confirmed numerous tiny nodular lesions in both lungs. Mycobacterium tuberculosis was not detected in either the sputum or bronchoalveolar lavage samples. Neck CT showed a 1.1 cm ill-defined nodular lesion with calcification in the right thyroid gland. Fine needle aspiration of the thyroid gland and multiple metastatic neck lymph nodes was performed and the histopathologic finding yielded a diagnosis of metastatic papillary thyroid cancer. He was scheduled to undergo total thyroidectomy in combination with radioactive iodine treatment. If miliary infiltrates are found on chest radiography, metastatic tumours including papillary thyroid cancer as a differential disease mimicking miliary tuberculosis should be considered to avoid misdiagnosis and delayed diagnosis.