上海交通大学耳鼻咽喉科学英文版课件 nasopharygeal carcinoma.pptVIP

Nasopharygeal Carcinoma * Rare in the US, more common in Asia High index of suspicion required for early diagnosis Nasopharyngeal malignancies SCCA (nasopharyngeal carcinoma) Lymphoma Salivary gland tumors Sarcomas Anteriorly -- nasal cavity Posteriorly -- skull base and vertebral bodies Inferiorly -- oropharynx and soft palate Laterally -- Eustachian tubes and tori Fossa of Rosenmuller - most common location Close association with skull base foramen Mucosa Epithelium - tissue of origin of NPC Stratified squamous epithelium Pseudostratified columnar epithelium Salivary, Lymphoid structures Chinese native Chinese immigrant North American native Both genetic and environmental factors Genetic HLA histocompatibility loci possible markers Environmental Viruses EBV- well documented viral “fingerprints” in tumor cells and also anti-EBV serologies with WHO type II and III NPC HPV - possible factor in WHO type I lesions Nitrosamines - salted fish Others - polycyclic hydrocarbons, chronic nasal infection, poor hygiene, poor ventilation WHO classes Based on light microscopy findings All SCCA by EM Type I - “SCCA” 25 % of NPC moderate to well differentiated cells similar to other SCCA ( keratin, intercellular bridges) Type II - “non-keratinizing” carcinoma 12 % of NPC variable differentiation of cells ( mature to anaplastic) minimal if any keratin production may resemble transitional cell carcinoma of the bladder Type III - “undifferentiated” carcinoma 60 % of NPC, majority of NPC in young patients Difficult to differentiate from lymphoma by light microscopy requiring special stains markers Diverse group Lymphoepitheliomas, spindle cell, clear cell and anaplastic variants Differences between type I and types II III 5 year survival Type I - 10% Types II, III - 50% Long-term risk of recurrence for types II III Viral associations Type I - HPV Types II, III - EBV Often subtle initial symptoms unilateral HL (SOM) painless, slowly enlarging n