Image 9 of 33



Image Description

Well-differentiated squamous cell carcinomas show keratinzation in the form of abundant eosinophilic cytoplasm, keratin pearls, and/or intercellular bridges. Non-keratinizing or poorly-differentiated tumors require immunohistochemical demonstration of one or more of squamous markers (p40, p63, CK5, or CK5/6) and lack of TTF-1 to arrive at the correct diagnosis. Intracellular mucin may be present in scattered tumor cells.

Image 9 of 33