Classification of NPC
Nasopharyngeal Carcinoma Classifications
Several types of tumors can develop in the nasopharynx. Some of these tumors are benign (non-cancerous), while others are malignant (cancerous). Nasopharyngeal Carcinoma (NPC) is the most common malignant tumor of the nasopharynx.
The World Health Organization (WHO) classifies NPC into three types:
- Type I: keratinizing squamous cell carcinoma (well differentiated)
- Type II: non-keratinizing carcinoma (moderately differentiated)
- Type III: undifferentiated carcinoma
While rare, most NPC in Caucasian population is the keratinizing Type I. It is often associated with smoking and exposure to carcinogens. Type II accounts for about 60% of nasopharyngeal carcinomas in adults. In high-risk populations of Southeast Asia, researchers have found that virtually all malignancies are undifferentiated Type III.
Differentiated and undifferentiated are two sub-types of the disease and are treated in the same way (radiation therapy with or without chemotherapy). Differentiated mean that cells appear and act like normal cells. Moderately or undifferentiated cells don’t appear or act like normal cells. Undifferentiated is the most common type among the two.