To investigate the application value of needle aspiration cell block technique in preoperative molecular classification of breast cancer.

Seventy-five patients with breast cancer from March 2020 to July 2022 were selected as research objects. All patients were examined by needle aspiration cell block technique before surgery，and the application value of needle aspiration cell block technique in preoperative molecular typing of breast cancer was evaluated based on postoperative histopathological and immunohistochemical results. SPSS20.0 software was used to process the data. The measurement data conforming to normal distribution was represented by（

75 female patients diagnosed with highly suspicious breast cancer and breast cancer by needle aspiration cell block technique before surgery were all confirmed to be breast cancer by postoperative histopathological examination. The accuracy of needle aspiration cell block technique for breast cancer diagnosis was 100%. The comparison of preoperative needle aspiration and postoperative histopathological immunohistochemical results showed that，The coincidence rates of progesterone receptor（PR），estrogen receptor（ER），human epidermal growth factor receptor 2（Her-2）and nuclear proliferation antigen（Ki-67）were 97.3%（73/75），98.7%（74/75），97.3%（73/75）and 94.7%（71/75），respectively. There was no significant difference in the expression of each molecular marker between the breast cancer cell block and the corresponding tissue（P>0.05），and the total coincidence rate of preoperative needle aspiration cell block technique and postoperative histopathological molecular typing reached 96.0%.

Needle aspiration cell block technique is an accurate and easy method in preoperative diagnosis of breast cancer. It not only improves the accuracy of breast cancer diagnosis，further defines the molecular classification of breast cancer，and helps clinicians to grasp more accurate biological characteristics of breast cancer before surgery.