The Collaborative International Dictionary of English v.0.48:

Aden- \Aden-\ or Adeno- \Adeno-\[Gr. 'adh`n, 'ade`nos, gland.]
   Combining forms of the Greek word for gland; -- used in words
   relating to the structure, diseases, etc., of the glands.
   [1913 Webster] adenalgia