In the TNM staging system for solid tumors, what does the 'N' component primarily represent?

Explanation

The TNM staging system is a widely used classification for solid tumors. 'T' describes the size and local invasiveness of the primary tumor. 'N' describes the involvement of regional lymph nodes. 'M' indicates the presence or absence of distant metastasis. The histological grade of the tumor is part of tumor grading, not the TNM staging system itself.