[Alcian Blue and Leu 7 in the diagnosis of thyroid malignancy]

Alcian blue pH 2.5 and Leu 7 reactivities were tested in biopsy samples of thyroid neoplastic and non-neoplastic diseases (n = 30). Typical papillary carcinomas exhibited marked positivity in the apical zone of thyrocytes, but the negativity of most cases of follicular variants of papillary carcinoma and positivity found in the toxic goitres and exceptionally also in the follicular adenoma makes alcian blue of nearly no value for the differential diagnosis on cytodiagnostic level. The Leu 7 immunohistochemistry was specific for papillary carcinomas but with a very low sensitivity. Thus, its cytodiagnostic use would be not cost effective.