What are the examination methods for early diagnosis of nasopharyngeal carcinoma

Since the nasopharynx is located at the back of the nasal cavity, doctors need to use some examination methods and their own clinical experience to diagnose early nasopharyngeal carcinoma.

Indirect nasopharyngeal endoscopy

Indirect nasopharyngeal endoscopy is a simple, fast and effective routine examination method. Patients do not need to make special preparations, and the examination is painless and non-invasive. During the examination, the doctor wears a forehead mirror, holds a tongue depressor in his left hand, presses down the front 2/3 of the tongue, expands the distance between the pharyngeal arch and the tongue root, and holds a small round mirror with a diameter of 1.5 cm in his right hand. After slightly warming it on an alcohol lamp, he inserts it into the oropharynx and observes the nasopharynx with the help of light reflection. The mirror rotates in different directions to observe the conditions of various parts of the nasopharynx. If the patient's pharyngeal reflex is sensitive, the doctor will spray the pharynx with 1% to 2% of cacao 1 to 3 times for mucosal surface anesthesia before examination.

Currently, long fiberoptic soft mirrors are mostly used in clinical practice. They are passed through the nasal cavity or oral cavity to penetrate deep behind enemy lines, and can be used for close observation and photography. Patients generally do not need to make special preparations before the examination.

EBV-related tests

Currently, the methods used to test the antibodies and free DNA of EB virus in the blood include IgA/VCA, IgA/EA and other tests, which can indirectly infer the possibility of tumor presence in the body. The method is simple and can be used in grassroots units. It is now mostly used to screen some high-risk groups. The latter is the direct quantitative detection of plasma free EB virus DNA with the development of quantitative PCR technology. It is reported that the fluorescence quantitative PCR method has good accuracy in diagnosing nasopharyngeal carcinoma (sensitivity and specificity can reach 90%). In addition, this indicator can more sensitively reflect the tumor burden in the body and can warn of tumor recurrence or distant metastasis to a certain extent.

It should be emphasized that the results of EB virus serology alone cannot determine whether it is nasopharyngeal carcinoma. It must be combined with other clinical examinations. If there are abnormal lesions in the nasopharynx, a nasopharyngeal biopsy should be performed. If there are no abnormalities in the nasopharynx and no enlarged lymph nodes in the neck, dynamic monitoring can be carried out through regular examinations.

Pathological diagnosis

For patients who cannot be diagnosed clearly but are suspected of nasopharyngeal cancer, a pathological examination is usually required. A small piece of cancerous tissue is bitten with biopsy forceps and sent to the pathology department for examination. The pathologist observes whether there are cancer cells under a microscope and classifies them according to some characteristics of the cancer cells. The pathology results can usually be obtained within 2 to 3 days.