We report the 402C-G FOXL2 mutation status in 1 epithelial ovarian lesion in a 38-yr-old woman showing stromal proliferations that were morphologically indistinguishable from adult granulosa cell tumor (AGCT). The lesion was a serous borderline tumor. The AGCT-like components were distributed within the septa and cyst walls. FOXL2 mutation was absent. The combination of an epithelial neoplasm and AGCT-like areas is rare but described. The AGCT-like components are likely to be tumor-like proliferations but not truly neoplastic AGCT. FOXL2 mutation testing may be useful in confirming an AGCT-like component.