case_images: PMC5292170_01
case_images: The rectovaginal mass on pelvic MRI (T2-weighted, sagittal line). The mass with multilocular cyst (indicated by C) and solid (indicated by S) components and a maximal diameter of 9 cm locates in the rectovaginal pouch. The uterus is indicated with an arrowhead, and the rectum is indicated with an arrow.
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case_images: fig1
case_images: WBC and CRP and an elevation of CA125 (114 U/mL) and CA19-9 (402 U/mL). We had a diagnosis of the rupture or torsion of the ovarian malignant tumor because of the findings of magnetic resonance imaging revealing the suspicion of hemorrhage within the rectovaginal mass (Figure 1), and an operation was performed by the accommodation of the acute abdomen within one day after admission.
case_images: View of the rectovaginal pouch during the operation. The cystic and solid mass, indicated by arrows, is present in the rectovaginal pouch and it is located separately from normal bilateral ovaries (R, right ovary; L, left ovary).
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case_images: fig2
case_images: A cystic and solid mass, with a maximal diameter of 90 mm, was present in the rectovaginal region, the mass did not connect to the bilateral ovaries, and the bilateral ovaries and fallopian tubes showed no abnormality (Figure 2).
case_images: Gross appearance of the solid part of the rectovaginal mass in the cut section. Note the gray-colored fibrous appearance in the solid part.
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case_images: fig3
case_images: The solid area showed a gray-colored fibrous appearance (Figure 3).
case_images: Loupe image of cystic endometriosis (indicated by CE) and fibroma (indicated by F). HE stain.
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case_images: fig4
case_images: Histologically, in the cystic area, variously sized cysts with the lining of endometrial tissue in the cyst wall were present (Figures 4 and 5), which indicated a diagnosis of cystic endometriosis (endometriosis with cystic change).
case_images: Endometrial tissue in the cyst wall of cystic endometriosis. HE stain.
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case_images: fig5
case_images: Histologically, in the cystic area, variously sized cysts with the lining of endometrial tissue in the cyst wall were present (Figures 4 and 5), which indicated a diagnosis of cystic endometriosis (endometriosis with cystic change).
case_images: A primordial follicle in the ovarian stroma. (a) Note the spindle cell layer (indicated by S) around the endometrial tissue (indicated by E) of cystic endometriosis. A primordial follicle (indicated by an arrow) is present in the spindle cell layer. HE stain. (b) Many spindle cells show positivity for PgR immunostain, which indicates that the spindle cell layer is an ovarian stroma. (c) High-power view of primordial follicle. HE stain. (d) Granular cells consisting of primordial follicle show positivity for alpha-inhibin immunostain.
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case_images: fig6
case_images: In the larger cysts, a spindle cell layer around the endometrial lining layer of the cyst wall was present (Figure 6(a)). The spindle cells showed positivity for PgR (Figure 6(b)) and week positivity for ER. In the spindle cell layer, the presence of the primordial follicle in a few sites was noted (Figures 6(a), 6(c), and 6(d)).
case_images: Histological appearance of the fibroma. (a) The fibroma (indicated by F) is present adjacent to endometrial tissue (indicated by E) of cystic endometriosis. HE stain. (b) High-power of the fibroma. Note the increase of the admixture of fibroblasts and collagen fibers. HE stain.
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case_images: fig7
case_images: In the solid area, spindle cells with bland nuclei and scant cytoplasm were arranged in intersecting bundles admixed with collagen (Figures 7(a) and 7(b)).