December 15, 2023
Nonkeratinizing squamous cell carcinoma (NKSCC) is a type of cancer made up of squamous cells that have not undergone keratinization. Keratinization is a process where cells produce and accumulate large amounts of a protein called keratin. As a result, the squamous cells in NKSCC look less pink and more blue when examined under the microscope.
Common locations for NKSCC include the oropharynx (tonsils, base of tongue, and soft palate), nasopharynx, sinonasal tract (nasal cavity and paranasal sinuses), lungs, cervix, and anal canal. Less common locations include the oral cavity and larynx. Another name for NKSCC in the nasopharynx is nasopharyngeal carcinoma.
The cause of NKSCC depends on the location in which the tumour starts. Most tumours in the oropharynx, nasal cavity, paranasal sinuses, cervix, and anal canal are caused by long-standing infection with human papillomavirus (HPV). Similarly, the vast majority of tumours in the nasopharynx are caused by infection with Epstein-Barr virus (EBV). In contrast, most tumours in the lungs are associated with tobacco smoking.
The term metastatic non-keratinizing squamous cell carcinoma is used to describe tumour cells that have spread from the original location of the tumour (this is called the primary tumour) to another part of the body such as a lymph node.
When examined under the microscope, NKSCC is made up of large squamous cells that appear blue when stained with hematoxylin and eosin (H&E). The cells appear blue because the nucleus of the cell (which normally appears blue) is very large while the cytoplasm (body of the cell) contains very little keratin (which normally appears pink). The tumour cells are often arranged in groups which may be described as sheets or nests.
Doctors wrote this article to assist you in reading and comprehending your pathology report. Feel free to reach out to us with any questions about this article or your pathology report. To get a comprehensive introduction to your pathology report, read this article.