Serous Borderline Tumor vs Carcinoma

Comments:
Serous Borderline Tumor (SBT) vs Serous Cystadenocarcinoma: The main distinguishing feature between the two is the presence of invasion in the latter. Small foci (< 5 mm) of microinvasion are acceptable within the spectrum of SBT.

Serous cystadenocarcinoma has larger obvious areas of invasion consisting of small irregular nests or isolated tumor cells within desmoplastic stroma.

This image of a SBT of the testis shows pseudostratified columnar epithelium lining the papillae. The tumor cells lack significant atypia and have elongated oval nuclei with multiple punctate nucleoli.