Fig. 2.
ARID1A expression in SMBT-23 which contains both atypical proliferative (borderline) seromucinous tumor (A, B) and associated endometriotic cyst (C, D). ARID1A staining was not detected in the epithelial cells of the endometriotic cyst (stromal cells serving as the positive control) and in the majority of tumors cells from the seromucinous tumor. There are occasional ARID1A positive tumor cells in the seromucinous tumor component and those positive cells contain abundant eosinophilic cytoplasm and appear extruded from the epithelial layer (inset).