Implementation of a Microwave-assisted Tissue-processing System and an Automated Embedding System for Breast Needle Core Biopsy Samples: Morphology, Immunohistochemistry, and FISH Evaluation

A platform composed of a microwave (MW)-assisted tissue-processing system and an automated embedding system has been recently introduced in pathology laboratories. Needle core biopsy (NCB) is an established, highly accurate method for diagnosing breast lesions and for providing important patho- logic, predictive, and prognostic information such as biomarker expression in case of breast carcinoma. The aim of this study was to evaluate whether breast NCBs processed with the MW- assisted tissue-processing system and automatically embedded show good-quality histology preparations and whether they are suitable for the assessment of estrogen receptor (ER), proges- terone receptor (PR), Ki-67, and HER2 in breast carcinoma. A series of 233 consecutive breast NCBs processed by both con- ventional and MW-assisted tissue-processing systems was included in this study. The histomorphologic and immunohisto- chemical quality, as well as the results of the evaluation of the biomarkers, were compared—the conventional processing method being the gold standard for comparison. The quality of hematoxylin-eosin and immunohistochemical tissue sections provided by the new system is comparable to that obtained after the conventional processing method. Moreover, in breast car- cinomas, a perfect agreement between the paired tissues when evaluating ER and PR status (Cohen k = 1) and a very good agreement when evaluating Ki-67 (k = 0.91) and HER2 (k = 0.93) have been found. In conclusion, applying strict cri- teria in tissue-handling steps, breast NCB can be processed and automatically embedded with these platforms. The diagnos- ability and the evaluation of the main prognostic and predictive biomarkers have been proved to be reliable.