Clinicostatistical study of low potential malignancy ovarian cystadenoma (borderline cases)

The number of ovarian cystadenoma of low potential malignancy (abbreviation: LPM) was 31 (5.7%) among common epithelial tumors [benign cystadenoma = 400 (74.0%), carcinoma = 110 (20.3%)]. Their mean ages, bilaterlity, frequency of ascites and nulligravidity were situated intermediately between those of benign cystadenoma and carcinoma. Abdominal tumor, distention, pain and metromenorrhagia were the main symptoms, although gastrointestinal complaints were rare in LPM cystadenoma. With LPM cystadenoma, 19 (61.3%) patients were at stage I, 7 (22.6%) at stage II and 5 (16.1%) at stage III, but with carcinoma, 44 (40.0%) were at stage III-IV [33 (30.0%) at stage I, and 31 (28.2%) at stage II]. The 5-year actuarial survival rate was 90% for LPM cystadenoma, but 43% for carcinoma. These results suggest that the clinical and biological features as well as the histological definition of LPM cystadenoma are situated intermediately between those of benign cystadenoma and carcinoma.