Cystic lymph node metastases of squamous cell carcinoma of Waldeyer's ringorigin

We analysed in a retrospective study the frequency of cystic lymph node (LN ) metastases in neck dissection specimens of 123 patients with primary squa mous cell carcinoma (SCC) arising in the palatine tonsils (62 M/14 F), the base of the tongue (38 M/5 F) and the nasopharynx (2 M/2 F). Eighty-two per cent of patients had metastases (64 tonsillar SCC, 33 base of tongue SCC a nd all four nasopharynx SCC) in 368 LN of a total 2298 sampled LN. Thirty-n ine per cent of patients had exclusively solid metastases and 37% of patien ts had exclusively cystic metastases. A total of 62 patients had some signs of cyst formation in one or more metastatically affected LN (27 with only histological evidence of cyst formation with luminal diameters < 5 mm, 35 w ith clinically detectable cyst with luminal diameter > 5 mm). Cystic metast ases were more common in patients with SCC of the base of the tongue (P = 0 .005), while solitary clinically evident cystic metastasis with lumina > 5 mm were found exclusively in tonsillar carcinoma (P = 0.024). In comparison with solid metastases, cyst formation was associated with N-categories (N2 b and N3, P = 0.005) in SCC of the base of the tongue origin. No such assoc iation was observed for tonsillar SCC (P = 0.65). The primary mechanism of cyst formation was cystic degeneration.