Papillary carcinomas - Figure 13. Cytological presentation - focal lymphocytic thyroiditis.

Lymphocytes are frequently found on the smears of papillary carcinoma. If the tumor is composed of non-metaplastic cells, the presence of lymphoid elements only rarely hinders the correct diagnosis. On the other hand, the presence of lymphocytes may cause great concern and difficulties if oxyphilic cells predominate smear and even more problem may arise if lymph cytes are present within oxyphilic cell groups. The presence of inclusions may be of help but this sign has significantly less specificity in Hürthle-cells. The whole cytological pattern, i.e the arrangement of cells, the presence of papillary structures and the sonograhic presentation has to be taken into account in the correct diagnosis.