THYROID METASTASES FROM A DUCTAL CARCINOMA OF THE BREAST - A CASE-REPORT

A case of bilateral thyroid metastases from ductal carcinoma of the br east is presented with emphasis on some unusual clinical findings: pre sentation after a long disease-free interval; clinical signs mimicking an acute thyroiditis; cystic structure of the left-sided metastatic n odule. Fine needle aspiration cytology from both nodules showed highly atypical tumor cells, such as to warrant a differential diagnosis bet ween metastatic breast cancer on the one hand and anaplastic and medul lary carcinoma of the thyroid on the other. Immunophenotypic study of the neoplasm on a cell block preparation of the aspirated material sho wed negativity for both thyroglobulin and calcitonin; instead, the tum or cells were strongly stained with antibodies against the ''breast-re lated'' markers alpha-lactalbumin and gross cystic disease fluid prote in-15. Therefore, immunochemistry allowed us to establish a definite d iagnosis of metastatic breast disease of the thyroid, thereby avoiding surgical procedures.