To evaluate the clinicopathological characteristics of mucinous borderline tumor associated with mature cystic teratoma and the origin of its cell type.

Five patients who were diagnosed as mucinous borderline tumor associated with mature cystic teratoma and treated in Samsung Cheil Hospital from January 1996 to September 2004 were analyzed. In addition MEDLINE, other data bases in English as well as in Korean revealed two more cases. We analyzed the result with patient's characteristics, preoperative symptoms, mass sizes, serum CA-125, operative procedure, stages, recurrence and survival period. Histological slides of the specimens were analysed for expression of cytokeratin (CK)-7 and cytokeratin (CK)-20 by immunohistochemical staining to know the origin of the cell.

The mean age was 45 years (25-61 years). Preoperative symptoms were palpable abdominal mass, abdominal pain and urinary frequency. The mean level of CA-125 was 46.05 U/mL and the mean tumor size was 16.75 cm (8.8-22.0 cm). Post surgical FIGO staging was; stage Ia in 6 cases, stage Ic in 1 case. Four cases were CK7(-)/CK20(+), reflecting gastrointestinal origin, and also showed pattern of pseudomyxoma peritoneii. Mean survival period was 32.7 months (6-67 months) without evidence of recurrence, except one case.

Our findings suggest that mucinous borderline tumor associated with mature cystic teratoma, is diagnosed at relatively young age and early stage, associated with good prognosis.