Ovarian Mucinous Neoplasms: How Reproducible are Current Diagnostic Categories?

Primary ovarian mucinous tumors represent a heterogeneous group of neoplasms that can be diagnostically challenging. Our guest, Dr. Pavel Dundr and his coauthors analyzed 124 tumors that were originally diagnosed as mucinous borderline tumors (MBTs) or mucinous carcinomas (MCs), with an emphasis on interobserver diagnostic agreement and assessment of the potential utility of molecular profiling.

Only a moderate agreement in diagnosis was found between the 13 observers on the study (k 0.524, for mucinous cystadenoma vs MBT vs MC). A perfect agreement for the distinction between mucinous cystadenoma/MBT - as a combined category - and MC was found in only 36.3% of cases. Differentiating between MBTs and MCs with expansile invasion was particularly problematic.

A comparison of molecular findings between the MBT and MC groups did not show major unequivocal differences. Interestingly, HER2 overexpression or amplification was found in 5.3% of MBTs, 35.3% of all MCs and in 45% of MCs with expansile invasion.