Hematoxylin and eosin stain of mouse ovaries in Fanca ^−/− , Aldh9a1 ^−/− , and dKO mice. (A) (1–3) Age-related atrophy of the ovary: (1) WT-1, (2) Fanca KO-2, (3) Aldh9a1 KO-2, 20× magnification. (4) Ovarian sex cord stromal tumor, mixed subtype (dKO-2, plan type, 20× magnification, 2x/0.06 numerical aperture), a well-demarcated, solid, multilobular, and moderately heterogeneous nodule diffusely replaces the ovarian parenchyma. (5) Ovarian sex cord stromal tumor, luteoma subtype (dKO-6, plan type, 20× magnification, 2x/0.06 numerical aperture), a well-demarcated, solid, and predominantly homogeneous nodule diffusely replaces the ovarian parenchyma. (6) Ovarian tubulostromal adenoma (dKO-8, plan type, 20× magnification, 2x/0.06 numerical aperture), a well-demarcated heterogeneous nodule contiguous with the surface epithelium diffusely replaces the ovarian parenchyma and slightly extends into the hilus. Variably cystic tubular structures are interspersed with solid areas of sex cord stromal cells. 7–8) higher magnification of ovarian sex cord stromal tumor, mixed subtype (dKO-2, plan type, 200× and 400× magnification respectively, 20×/0.50 and 40×/0.75 numerical aperture, respectively), composed of a mixture of sex cord stromal cells at various degrees of differentiation. 9–10) tubulostromal adenoma (dKO-14, plan type, 200× and 400× magnification respectively, 20×/0.50 and 40×/0.75 numerical aperture respectively), composed of variably dilated tubules lined by cuboidal epithelium intermixed with small packets of sex cord stromal cells at various degrees of differentiation. 11–12) Ovarian sex cord stromal tumor, luteoma subtype (dKO-11, plan type, 200× and 400×magnification, respectively, 20×/0.50 and 40×/0.75 numerical aperture, respectively), composed of packets of highly luteinized polygonal cells supported by a mild fibrovascular stroma. dKO, double KO (Fanca^−/−Aldh9a1^−/−). Images were obtained using an Olympus BX45 microscope equipped with an Olympus DP26 camera. Olympus cellSens Entry v1.18 imaging software was used for image acquisition.