A simple method for estrogen receptor antigen preservation in cytologic specimens containing breast carcinoma cells

We report a modified method to prepare cytologic specimens for the evaluation of estrogen receptors by immunocytochemistry. Cytologic samples were obtained by needle aspiration of tumor masses (nine patients) and body cavity fluids (nine patients). The cytologic material was divided, and slides for immunostaining were prepared according to two different techniques: (1) fixation of cells in suspension (modified method); and (2) fixation of cells adherent to slides (standard method). The results after immunostaining demonstrated that the number of cells adhering to slides prepared according to the modified method was greatly increased as compared with the number of cells remaining attached to slides prepared according to the standard method. There was no loss of cell groups or aggregates using the modified method. The antigenicity of estrophilin and the cell morphology were well-preserved for up to 30 days. With this modified method, cytologic samples may be stored and conveniently processed in batches, thereby improving the utilization of laboratory resources.