Standard and immunohistochemical staining methods for diagnosis of cervical lymph node metastasis in nasopharyngeal carcinoma
Nasopharyngeal carcinoma (NPC) is a rare cancer in the Western hemisphere (1 case per 100,000 individuals). Conversely there are some areas, such as Southern China, Southeast Asia (Vietnam), the Mediterranean basin and Alaska, where morbidity reaches 80 per 100,000 individuals. Detecting cervical lymph node metastasis is important because it helps recommend the radiation dose and the chemotherapy strategy. We compared the diagnostic value of hematoxylin-eosin (HE) staining and a immunohistochemistry technique to determine the pathological features of tumors, in 53 samples of cervical lymphadenopathy from 30 patients with NPC. With HE, metastasis was detected in 41 of 53 samples with NPC and cervical lymphopathy. In the remaining 12 slides, the HE staining did not show signs of metastasis. Staining with immunohistochemistry revealted that 10 of 12 “negative” diagnoses based on HE staining, were actually metastatic. This means that 20% of the patients would not receive correct treatment based on HE staining alone. We conclude that immunohistochemistry is a highly sensitivity technique that can detect metastases that are not diagnosed by HE staining.