Background The present study retrospectively determined the outcomes and prognoses in stage I mucinous ovarian carcinoma according to histological type (ie, expansile or infiltrative).

Methods A centralized pathologic review of tumors in patients treated from 1976 to 2016 for ovarian mucinous carcinoma was performed by 2 expert pathologists according to the 2014 World Health Organization classification. Only patients with stage I disease were analyzed. Tumors were typed as expansile or infiltrative and oncological issues analyzed.

Results A total of 114 cases were reviewed. Fifty were excluded (stage > I in 30 cases and no accessibility to a pathological review for 20 cases). Thus, 64 patients fulfilled the inclusion criteria: 29 had expansile-type and 35 infiltrative-type disease. The characteristics of both groups of patients were comparable, except the use of nodal staging surgery, which was more frequent in patients with infiltrative type. The International Federation of Gynecology and Obstetrics stages in expansile and infiltrative types were as follows: IA in 13 (45%) and 20 (57%), and IC in 16 (55%) and 15 (43%), respectively. Recurrence occurred in 3 patients with expansile type and 6 patients with infiltrative type. Two cases of expansile recurrence had pelvic recurrence and were salvaged after secondary surgery and chemotherapy, whereas 5 cases of infiltrative recurrence had extrapelvic spread and died from disease or were alive with progressive disease.

Conclusions Recurrence occurred in both types of stage I mucinous ovarian cancer. However, lethal recurrences were observed mainly in infiltrative type.