Prognostic significance of microscopic and macroscopic extracapsular spread from metastatic tumor in the cervical lymph nodes
It has been established that the presence or absence of cervical node metastases in patients with head and neck squamous cell carcinoma (HNSCC) is a powerful prognostic indicator. This report reviews the evolution of thinking over the past 70 years with regard to the import and detection of cervical nodal metastases which exhibit spread of tumor beyond the confines of the original encompassing nodal capsule. In the process, this discussion touches upon clinical examination, gross and microscopic pathologic examination, and radiographic imaging studies. In particular, the distinction between gross nodal extracapsular spread of tumor and microscopic nodal extracapsular spread of tumor has been drawn in recent reports; this raises the possibility that identification of microscopic breaching of the nodc capsule by tumor might provide clinically significant information which is not provided by the gross observation of an intact lymph node capsule. While it remains to be seen whether microscopic extracapsular spread alone will prove to be an important prognostic factor, it is recommended that selective neck dissection continue to be offered even in those patients with clinically negative necks; further studies should aid in defining the import of microscopic extracapsular tumor spread in patients with positive cervical nodes.