Occult papillary carcinoma of the thyroid with pulmonary lymphangitic spread diagnosed by lung biopsy.

Distant metastases from occult papillary carcinoma of the thyroid, which is defined as a tumor less than 15 mm in diameter, are extremely rare. A 21-year-old patient with miliary micronodular densities in both lungs is described, in whom pulmonary lymphangitic spread of occult papillary thyroid carcinoma was diagnosed by thransthoracic lung biopsy.