Here are pictures of ganglion cysts or mucus cysts on fingers and toes (some of them mine and others gotten from the Net).
My recommended treatment is monitor / watchful waiting and if necessary, needle aspiration.
Ganglion Cyst or Mucus Cyst on the Thumb
Note the colorless sticky gel or fluid coming out.
Copied from the Net:
Ganglion Cyst or Mucus Cyst on the Toe
Copied from Net