Background: Although in the English literature, much has been published about ovarian teratoma, no large series has been reported in Taiwan. Therefore a retrospective study of 283 consecutive cases of mature cystic teratomas of the ovary, operated at National Taiwan University Hospital between 1988 and 1993, was undertaken.
Methods: This series was based on a retrospective chart study at the Department of Obstetrics and Gynecology of the National Taiwan University Hospital from 1988 to 1993. All cases included in this study were proven by pathology review. The clinical data, pathology and complications are summarized.
Results: The incidence of mature cystic teratoma was 32.6% of primary ovarian neoplasm. As for the age distribution, the youngest patient was 12 years old and the oldest, 76. The largest number of cases was found in patients between the ages of 20 and 30 years; the mean age was 35.4 years. Pain, the most common complaint, was noted in 48.1% of the cases in whom it varied from a dull ache to the sharp, stabbing pain of torsion. Of greater interest was an unexpectedly high incidence (16.6%) of asymptomatic cysts found on routine physical examination. The right ovary was involved in 51.2%, the left ovary in 40.6% and bilateral ovaries were involved in 8.2%. The incidence of torsion was 9.2%, and was the highest in all complications. Ten concurrent pregnancies were noted, an incidence of 3.5%. The incidence of malignant transformation was 0.7%, with a pathology of squamous cell carcinoma.
Conclusions: Mature cystic teratom is the most common germ cell tumor and accounts for about 33% of all ovarian neoplasm They occur primarily during the reproductive years, but may occur in the postmenopausal period or in childhood. A cystic teratoma can undergo malignant transformation; it occurs most frequently in postmenopausal women, and the prognosis is poor. However, it is a rare complicaiton, with an incidence less than 1%.