Branchiogenic carcinoma--conceptual or true clinico-pathological entity?

The existence of branchiogenic carcinoma remains controversial. According to some authors, this malignancy is more conceptual than a true clinicopathologic entity. The originally proposed diagnostic criteria of branchiogenic carcinoma have been subsequently challenged. Many reports regarding primary branchiogenic carcinoma have failed to provide sufficient evidence to distinguish this entity from nodal metastases arising from unrecognized primary tumours. There is growing evidence that the majority of branchiogenic carcinomas are in fact cystic metastases from oropharyngeal carcinoma, most commonly originating in the tonsils, and not true carcinomas arising in a branchial cleft cyst. The missing link between branchial cyst and branchiogenic squamous cell carcinoma could be fulfilled by the occurrence of in situ branchial cyst carcinomas, yet such cases are extremely rare. Isolated cystic neck lesions, necessitate a thorough search for a primary tumour, similarly to other occult primaries presenting with cervical metastases. The treatment of cervical cyst with dysplasia or carcinoma in situ includes complete surgical excision. The true branchiogenic carcinomas should be approached with postoperative irradiation to the half neck. A cervical metastatic cystic squamous carcinoma of unknown origin should be treated as for other cases of occult primaries, i.e. with surgery and radiotherapy. The data on the prognosis of branchiogenic carcinoma are scarce, though long-term survival has been reported. Further histopathologic and clinical studies are warranted in order to better understand the biology and natural history of cervical cystic lesions. The existence of true branchiogenic carcinoma remains to be verified with new clinical and molecular criteria.