Cystic lymph node metastasis in patients with head and neck cancer: An HPV-associated phenomenon

Background. Cystic lymph node metastases have been associated with tonsil cancer. A subset of oropharyngeal cancers contain human papillomavirus (HPV) DNA. The clinical and virologic associations of cystic nodal metastasis in head and neck cancer (HNSCC) were investigated. Methods. A retrospective review of patients undergoing neck dissection between 2002 and 2004 identified patients with cystic lymph node metastases. Clinical and pathologic information was recorded. The presence of HPV DNA was analyzed using in situ hybridization in a subset of patients. Results. One hundred neck dissections were reviewed and 20 had cystic nodes. Seventeen of these patients had primary tumors arising in the palatine or lingual tonsil. Three were "unknown primary." HPV DNA was present in 11 of 13 patients with cystic metastases with tissue available for analysis (87%). No HPV DNA was identified in tumor from 21 patients with solid nodal metastasis (p <.0001). Conclusion. Cystic cervical lymph node metastasis is strongly associated with HPV-related tonsillar HNSCC.