Effectiveness of tissue microarray technique for the assessment of estrogen and progesterone receptors expression in endometrioid endometrial cancer – preliminary report

Objectives: To assess the effectiveness of the donor-block biopsies with a 2 mm-size needle in endometrioid endometrial cancer (EEC) in the tissue microarray (TMA) technique and the application of the TMA for estrogen receptors (ER) and progesterone receptors (PR) expression in EEC. Material and methods: The study examined EEC tissues from 60 patients. Tissue cores, 2 mm in size, in duplicate, were taken from the formalin-fixed and paraffin-embedded tissue donor blocks and constructed into the TMA recipient block. The presence of EEC tissue in the TMAs was analyzed, and the ER and PR expressions were examined. Results: EEC tissue in TMAs was confirmed in 56 cases (93.33%). In 49 of them (81.67%), both cores presented with cancer tissues. In 4 cases (6.67%) EEC tissue was absent. All cases with ECC present on the TMA slides were appropriate for the ER and PR analysis. In 29 EEC cases (51.98%) both ER and PR were expressed. In 3 cases (5.36%) only ER was expressed, in 8 cases (14.29%) only PR was expressed, and in 16 cases (28.57%) ER and PR were assessed as negative. Conclusions: Two 2 mm-sized tissue cores from donor-block biopsies constructed into the TMA recipient block were sufficient to diagnose EEC and enabled the assessment of ER and PR expression in 93.3% of the cases. The use of the described TMA technique makes the immunohistochemical study of EEC easier and more timeefficient