Psammoma bodies in fine needle aspirate of the thyroid in lymphocytic thyroiditis.

Psammoma bodies are concentric, laminated microcalcifications that are regarded as nearly specific markers in the thyroid gland for the presence of papillary carcinoma. While psammoma bodies have been seen rarely in some benign thyroid diseases, there appear to be no reports of psammoma body formation in lymphocytic or Hashimoto's thyroiditis. We report a case of Hashimoto's thyroiditis in which psammoma bodies were identified in a fine needle aspiration specimen of the thyroid and in histologic sections of the right thyroid lobectomy; papillary carcinoma was not found in either specimen. We conclude that psammoma bodies may be seen in any benign process, such as nodular goiter or lymphocytic thyroiditis, that produces reactive papillary hyperplasia of thyroid epithelium, as well as in papillary carcinoma. However, the finding of psammoma bodies in a fine needle aspirate without corroborating cytologic evidence of papillary cancer is still an indication for surgical removal of the thyroid nodule since these structures are reliable markers for occult papillary carcinoma of the thyroid, despite the rarity of their formation in benign diseases.