[Poorly differentiated carcinoma of the thyroid--immunohistochemical evaluation of p53 and p27 protein expression].

Thyroid carcinomas represent a broad spectrum of tumours with different biologic behaviours. The gap between the indolent course of well-differentiated papillary and follicular carcinomas and the very aggressive behaviour of anaplastic carcinomas is filled by variants of thyroid carcinoma with intermediate prognosis, designated in the literature as poorly differentiated (with insular, trabecular and solid patterns) and tall/columnar cell variant of papillary carcinoma. The study has been carried out in 103 patients who had thyroid cancer with various grade of differentiation. The diagnostic significance of p53 and p27 expression in tumor cells has been investigated by immunohistochemical analysis. Well differentiated carcinomas have exhibited the lowest p53 staining frequency, the expression has been higher in poorly differentiated carcinomas and 100% of anaplastic carcinomas have been positive p27 immunohistochemistry has been positive in 80% of investigated carcinomas (in 15% strong positive reaction). In the group of poorly differentiated tumours positive reaction has been observed in 75% cases (in 15% strong positive reaction). Our data suggest that expression of p53 and p27 seems to have limited routine diagnostic significance, but p53 positivity is a good marker of tumour progression.