Malignant degeneration of mature cystic teratomas has been reported in
1-3% of cases, A patient with the unusual occurrence of a stage IIIC
squamous cell carcinoma arising in a mature teratoma over 50 years aft
er initial diagnosis is presented, The patient was treated with pelvic
radiotherapy, The role of serum squamous cell carcinoma antigen in de
tecting degeneration of mature cystic teratomas at an early stage is c
onsidered. (C) 1995 Academic Press, Inc.