Diagnostic utility of immunohistochemical analysis and Epstein–Barr virus‐encoded small RNAs in situ hybridisation of cell block sections obtained using fine‐needle aspiration in nasopharyngeal carcinoma with lymph node metastasis

OBJECTIVE: This study aimed to investigate the diagnostic utility of immunohistochemistry (IHC) analysis (FNA) and Epstein-Barr virus- (EBV) encoded small RNAs (EBERs) in situ hybridisation analyses of cell block (CB) sections obtained using fine needle aspiration in nasopharyngeal carcinoma (NPC) with lymph node metastasis. METHODS: A total of 38 FNA biopsies were collected using a Youyi aspirator. The cytomorphology, CB-based histomorphology, IHC, and EBERs in situ hybridisation were observed and the sensitivity/final diagnostic rates were compared with those of simple smears and a combination of smears and CBs. RESULTS: The 38 cases of metastatic lymph nodes from NPC displayed the morphological characteristics of non-keratinising carcinoma in cell smears and CB sections. The tumour cells showed high expression of CK5/6, P63, Ki-67, and EBERs (94.7%, 36/38 cases) in the CB sections. The sensitivity and the final diagnostic rates were lowest with the simple cell smears (86.8%, 33/38 and 71.1%, 27/38 cases), moderate with the smears combined with CB sections (92.1%, 35/38 cases and 81.6%, 31/38 cases), and the highest with IHC and EBERs in situ hybridisation (94.7%, 36/38 and 94.7%, 36/38 cases). CONCLUSIONS: FNA has great value in the diagnosis of NPC with lymph node metastases, and using cell smears combined with IHC and EBERs in situ hybridisation of CB sections could help clinical doctors promptly identify the primary lesions.