Cystic lymph node metastases of head and neck squamous cell carcinoma: pitfalls and controversies.

Lymph node metastases of squamous cell carcinomas in the neck can appear cystic. Without a clinically apparent primary tumour they can classically be considered to originate in a branchial cleft. We report two cases of cystic squamous cell carcinoma with histopathologic criteria of branchial cleft carcinoma. After a review of the literature, diagnostic strategies, histopathologic features, and therapeutic options for this very controversial clinical situation are discussed. We conclude by suggesting that Martin's criteria, largely used to differentiate between a cystic metastasis of a squamous cell carcinoma and a very theoretical branchial cleft carcinoma should be abandoned for lack of applicability.