Familial Nasopharyngeal Carcinoma 6

Pathology of Nasopharyngeal Carcinoma 73Fig. 7.2. Undifferentiatedcarcinoma featuringscattered loosely attachedtumor cells with plentifulintermixed lymphocytes.(Hematoxylin and Eosin,original magnification×600)Fig. 7.3. Not uncommonly,undifferentiated carcinomais composed of spindleshapedtumor cells (hematoxylinand eosin, originalmagnification ×400)7.2.3Keratinizing Squamous Cell CarcinomaKeratinizing squamous cell carcinoma (SCC) isuncommon in NPC-endemic regions. In endemicareas such as Singapore, it constituted between 1%and 20% of all cases of NPC (Shanmugaratnam etal. 1979; Tan and Putti 2005). In contrast, the proportionof this subtype in non-endemic westernpopulations has been reported in up to 67% of cases