Mucinous Borderline Tumour with Microinvasion Arising from a Mature Teratoma

Abstract

A mucinous borderline tumour with microinvasion arising from a mature teratoma is typically detected incidentally and diagnosed postoperatively with histopathological confirmation. Due to the limited cases reported in literature; therefore, no established management recommendation is currently available. We reported a 25-year-old woman who presented with a painless, large ovarian mass, and was associated with elevated cancer-antigen 125 (CA125). Pre-operative contrast-enhanced computed tomography (CT) reported a large multiloculated ovarian tumour (solid-cystic) otherwise, other findings were normal. Patient underwent staging laparotomy with fertility sparing surgery, with no evidence of residual disease. Following surgery, histopathological examination revealed mucinous borderline tumour with microinvasion (2mm) arising from mature teratoma. Immunohistochemical stain showed diffuse and strong expression of cytokeratin 7 (CK7), but heterogeneous expression of cytokeratin 20 (CK20) and caudal-type homeobox transcription factor 2 (CDX2). This case report highlighted the importance of histopathological evaluation in patient management, selection of surgical approach, disease surveillance and monitoring of disease progression in this condition.