WordNet (r) 3.0 (2006):

cytology
    n 1: the branch of biology that studies the structure and
         function of cells

Moby Thesaurus II by Grady Ward, 1.0:

38 Moby Thesaurus words for "cytology":
   aerobiology, agrobiology, anatomy, astrobiology, bacteriology,
   biochemics, biochemistry, biochemy, bioecology, biological science,
   biology, biometrics, biometry, bionics, bionomics, biophysics,
   botany, cell physiology, cryobiology, cybernetics, ecology,
   electrobiology, embryology, enzymology, ethnobiology, exobiology,
   genetics, gnotobiotics, life science, microbiology,
   molecular biology, pharmacology, physiology, radiobiology,
   taxonomy, virology, xenobiology, zoology