Papillary squamous carcinoma: will the real one please stand up?

Abstract

Summary: Pathologists seeking clinicopathologic definition of papillary squamous cell carcinoma may, at times, feel as if they have been given a pathologic salmagundi to digest. Why the definition of the carcinoma is so elusive is unclear. Perhaps one way to address the problem is to relate what the papillary squamous cell carcinoma is not. It is not the verrucous carcinoma nor is it the exophytic, conventional squamous cell carcinoma, which is usually broad-based, well-to-moderately differentiated, most often keratinizing, and with an easily defined invasive (endophytic) component. To date, however, the few reports dealing with papillary squamous cell carcinoma have muddied diagnostic waters by definitely not excluding these other forms of squamous cell carcinoma. Three different perceptions of papillary squamous cell carcinoma of the upper aerodigestive tract are presented in the commentary. Not only are the descriptions and depictions of the cytomorphology different among the three, so too are the biologic courses and responses to therapy. We believe the papillary squamous cell carcinoma is a separable and definable clinicopathologic entity. The reader is left to choose.