Utility of monoclonal PAX8 antibody for distinguishing intrathyroid thymic carcinoma from follicular cell-derived thyroid carcinoma.

Utility of monoclonal PAX8 antibody for distinguishing intrathyroid thymic carcinoma from follicular cell-derived thyroid carcinoma. Endocr J. 2018 Sep 12;: Authors: Suzuki A, Hirokawa M, Takada N, Higuchi M, Tanaka A, Hayashi T, Kuma S, Miyauchi A Abstract Follicular cell-derived thyroid carcinomas, including thyroid squamous cell carcinomas (SCCs) and anaplastic carcinomas, are immunoreactive for paired-box gene 8 (PAX8), while non-follicular cell-derived thyroid carcinomas stain negative for the PAX8 antibody. Intrathyroid thymic carcinoma (ITTC) arising from the intrathyroidal ectopic thymus exhibits moderate-to-strong nuclear reactivity for polyclonal PAX8. This is difficult to understand given that PAX8 is not associated with embryonic thymic development. We aimed to determine the diagnostic significance of monoclonal PAX8 antibody in distinguishing ITTCs from follicular cell-derived thyroid carcinomas. Ten ITTCs, 14 poorly differentiated thyroid carcinomas (PDTCs), 14 thyroid SCCs, 7 thymic tissue specimens, 7 thymomas, and 1 thymic carcinoma were analyzed using antibodies against polyclonal and monoclonal PAX8, thyroid transcription factor-1, p63, and CD5. Four ITTCs (40.0%) stained positive for polyclonal PAX8; none stained positive for monoclonal PAX8. All PDTCs and 92.9% of SCCs were immunoreactive for both polyclonal and monoclonal PAX8. All PDTCs, 46.2% of SCCs, and none of the ITTCs were immunoreactive for thyroid trans...
Source: Endocrine Journal - Category: Endocrinology Tags: Endocr J Source Type: research