Cystadenolymphomas are a special kind of salivary gland tumours with an epithelial and a stromal part. Mast cells, which in this tumour were only rarely mentioned, were observed in large amounts in the stroma and in the epithelium. This type of cell is present especially in those cystadenolymphomas rich in epithelial parts. The possible significance of this observation is discussed.

Twenty‐two adenolymphomas (Warthin's tumours) were investigated with respect to their lymphoid stroma; 4 were analyzed by monoclonal antibodies against B‐cells and T‐cells. A slight predominance of B‐cells was found. In the T‐cell fraction, the T‐helper cells outnumbered the T‐suppressor cells by a factor of 4. These and other cell types were found in the stroma and in the epithelium. Mast cells were associated with those adenolymphomas having a high proportion of epithelium.