Nasopharyngeal Non-Keratinizing Carcinoma

**Semantic type:** Neoplastic Process

**Definition:** A nasopharyngeal carcinoma characterized by the lack of keratinization and the presence of a dense lymphoplasmacytic infiltrate. The vast majority of cases are associated with Epstein-Barr virus infection. It is subdivided into differentiated and undifferentiated types, based on the cytologic features of the malignant cells. The differentiated type (type II) is characterized by the presence of smaller cells and cellular stratification reminiscent of transitional cell carcinoma. The undifferentiated type (type III) is characterized by the presence of cells with large vesicular nuclei with prominent nucleoli and a syncytial pattern of growth. While morphologically distinct, both types have similar clinical presentation and prognosis.

**Synonyms:** - NK-NPC - Nasopharyngeal Nonkeratinizing Carcinoma - Nasopharyngeal Throat Nonkeratinizing Cancer