Carcinomas of the oro/nasopharynx often present with regional lymph node (LN) metastases before the primary tumour is discovered. Some of the cervical LN metastases feature prominent cyst formation. Solitary cystic LN metastases have often been mistaken for primary squamous cell carcinomas (SCC) originating within a branchiogenic lateral neck cyst (LNC), resulting in the commonly used terms 'branchioma' and 'branchiogenic carcinoma ' (von Volkmann, 1882;Wolff et al, 1979;Khafif et al, 1989;Parks and Karmody, 1992;Carroll et al, 1993;Hall and Dexter, 1993;Flanagan et al, 1994;Knobber et al, 1995). For patients with an isolated finding of SCC in a neck LN, a search for a primary carcinoma in the upper aerodigestive tract is mandatory, including US, MRI and CT, as well as extensive biopsies of the base of tongue, nasopharynx and tonsillectomies in the case of clinically occult tumours (Spiro et al, 1983;Flanagan et al, 1994). This clinical practice has provided overwhelming evidence in recent years that isolated cystic SCC in neck LN are metastases from primary SCC of the palatine tonsils, the base of the tongue and the nasopharynx, tissues also collectively referred to as the Waldeyer's ring (Micheau et al, 1974(Micheau et al, , 1990Flanagan et al, 1994;Thompson and Heffner, 1998). Although this explanation has been slow to gain wide recognition and claims of the first true 'branchiogenic carcinoma' have been made rather recently (Micheau et al, 1974;Jones et al, 1993), cystic SCC in cervical LN is now regarded as a typical presentation of metastatic SCC arising in the oro/nasopharynx. At the same time, the idea of a primary branchiogenic carcinoma has become a vanishing concept (Thompson and Heffner, 1998). Despite the body of literature about this topic, there is little information regarding the frequency of cystic LN metastases from SCC of the Waldeyer's ring. Our goal was to establish the frequency of cystic LN metastases in our series of 123 patients with SCC of Waldeyer's ring origin who had been treated primarily surgically along with neck dissections. Furthermore, we discuss the morphological features and clues for establishing a diagnosis of cystic LN metastases rather than 'branchiogenic carcinoma'. 1984 and 1997, 108 patients with biopsy-proven SCC of Waldeyer's ring origin underwent neck dissections at the ORL Department of the University Hospital in Graz, Austria. Fifteen patients were treated at the Elisabethinen Hospital, Graz, Austria, between 1992 and 1997. Archival formalin-fixed, paraffinembedded haematoxylin and eosin (HE) stained sections of all primary SCC and their corresponding neck dissections were reviewed. SCC were separated into (1) tonsillar origin (palatine tonsil), (2) base of tongue origin and (3) nasopharyngeal origin. Extensive tumours involving the entire oropharynx, and multiple or synchronous intraoral carcinomas were not included in this study, because we were not able to determine the exact origin of the SCC in these cases. Initial diagnosis was established by biopsy and fol...