Pleural effusion resulting from metastatic papillary carcinoma of the thyroid.

We present a patient with a symptomatic pleural effusion resulting from papillary carcinoma of the thyroid metastatic to the pleura. Distinctive features include clinically evident pleural metastasis and the presence of psammoma bodies in the pleural fluid, which are characteristic (albeit not pathognomonic) of papillary carcinoma of the thyroid.