Classification of NPC
Nasopharyngeal Carcinoma Classifications
Several types of tumors can develop in the nasopharynx, an area in the back of the nose toward the base of skull. Some of these tumors are benign (non-cancerous), while others are malignant (cancerous). Nasopharyngeal carcinoma (NPC) is one type of cancer that develops in the nasopharynx and is the most common malignant tumor of the nasopharynx.
The World Health Organization (WHO) classifies nasopharyngeal carcinoma in three types:
- Type I: keratinizing squamous cell carcinoma (well differentiated)
- Type II: non-keratinizing carcinoma (moderately differentiated)
- Type III: undifferentiated carcinoma
Each of these NPC types are more common in some areas of the world than others. Type II accounts for about 60% of nasopharyngeal carcinomas in adults. While rare, most NPC in Caucasians is the keratinizing Type I. In high-risk populations of Southeast Asia, researchers have found that virtually all malignancies are undifferentiated Type III. Differentiated and undifferentiated are two subtypes of the disease and are treated in the same way. Undifferentiated is the most common type. Differentiated mean that cells appear and act like normal cells. Moderately or undifferentiated cells don’t appear or act like normal cells.