Cystic squamous cell carcinoma of the neck: could a second metastatic focus help?

Squamous cell carcinoma of the neck presenting clinically as predominantly cystic lesion has often been considered as branchiogenic carcinoma in the past. However, such cystic lesions presently constitute a distinct form of head-neck metastasis, and a co-existent second metastatic focus could supposedly help distinguish them from branchiogenic carcinoma. We here present a case where, although the primary remained elusive, the associated spinal metastasis precluded us from diagnosing a cystic squamous cell carcinoma as branchiogenic carcinoma. Thus a second metastatic focus, if found, could add to the existing knowledge to distinguish between a cystic squamous cell carcinoma and the so-called branchiogenic carcinoma, especially when the primary could not be found.