Ovarian tumors of low malignant potential: a retrospective study of 234 patients

Two-hundred and thirty-four consecutive patients with a histologic diagnosis of low malignant potential (LMP) ovarian tumors between 1972 and 1994 form the basis of this study. Six patients had a synchronous intra-abdominal or pelvic malignancy and six were considered to have areas of early stromal invasion, these patients being considered separately. The patients ages ranged from 16–93 years. The histologic type was mucinous in 53%, serous in 37%, mixed in 7%, and other in 3%. Ovarian tumors were bilateral in 15% with mucinous and 39% with serous disease. Fourteen patients had pseudomyxoma peritonei. Extra ovarian disease was found in 28 (34%) patients with serous and 15 (13%) with mucinous tumors. Five (6%) patients with serous tumors had invasive implants and four had lymph node implants. Clinically 175 patients had stage I disease, 19 had stage II and 28 stage III disease but only 88 patients were formally staged. Follow-up details were available for 173 (74%) patients, ranging from 2 months to 20 years, mean 54 months. Thirteen patients (6%) died of disease, of whom six had pseudomyxoma peritonei. Twelve patients (6%) had developed invasive malignancy of whom seven died. None of the patients with formally staged Ia or Ib disease had a recurrence. With the exception of patients with synchronous malignancy or pseudomyxoma peritonei the prognosis is good. Surgical staging offers limited prognostic information but sacrifice of fertility is not justified. Adjuvant therapy is not indicated in early stage disease and its role for patients with extra ovarian disease remains controversial.