PMC5457762_01
(a) Abdominal plain computed tomography (current). A huge mass measuring 21 cm in longest diameter can be seen in the right cranial portion of the uterine body. The mass is partially solid, suggesting malignancy. (b) Abdominal plain computed tomography (image obtained 10 years prior to the current admission). A mature cystic teratoma measuring 6 cm in diameter is observed on the right side. There are no findings suggestive of malignancy, such as a mural nodule or a solid component.
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Moreover, a tumor measuring 21 cm in longest diameter was detected in the pelvis (Figure 1(a)). Preoperative abdominal plain CT had revealed a right ovarian tumor measuring 6 cm in diameter (Figure 1(b)), which contained a part of calcification and fatty components; however, there had been no findings suggestive of malignancy, such as a solid component or a mural nodule.
Pelvic plain magnetic resonance imaging. (a) T2-weighted image in the sagittal plane. A cyst measuring 21 x 19 x 12 cm is observed. It is partially solid. (b) T2-weighted image in the horizontal plane. (c) Diffusion-weighted image in the horizontal plane. The solid components observed on the T2-weighted image show high signal intensity on the diffusion-weighted image ( ). The cyst is suspected to be a malignant lesion.
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Furthermore, pelvic plain magnetic resonance imaging (MRI) also showed a cyst measuring 21 cm in longest diameter that was partially solid on the right side of the uterine body (Figure 2(a)). The solid components detected on T2-weighted images (Figure 2(b)) showed high signal intensity on diffusion-weighted images (Figure 2(c)) and low signal intensity on apparent diffusion coefficient maps, which suggested a malignant lesion.
Resected specimen. Protruding lesions are observed on a portion of the wall of the right ovarian tumor.
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Moreover, protruding lesions were observed on a portion of the tumor wall (Figure 3).
Histologically, squamous cell carcinoma was observed inside the cyst (left side of the picture). Granulation tissue containing hair was also found (right side of the picture) (H&E staining, x100).
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There was a transition between squamous epithelium and squamous cell carcinoma (Figure 4).