case_images: PMC11263014_01
case_images: (A-D) Pelvic CT images. CT plain scan showed a left pelvic mass (A), contrast-enhanced CT showed a cystic solid pelvic mass with heterogeneous enhancement in the peripheral areas and a non-enhanced central area in arterial phas (B), venous phase (C), and delayed phase (D).
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case_images: PMC11263014_01_fmed-11-1393083-g001.jpg
case_images: fig1
case_images: Mean plain CT value: 46 HU; arterial phase: 73 HU; venous phase: 107HU; delayed phase: 91 HU (Figures 1A-D).
case_images: (A-D) Pelvis MR images. (A) T1-weighted image. MRI showed small foci of markedly low intensity (white arrow) on T2-weighted images (B) and contrast enhanced T1-weighted images demonstrated hyperenhancement within the solid component of the mass (C). This area corresponded to hyperintensity on DWI (b = 800) (D).
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case_images: PMC11263014_01_fmed-11-1393083-g002.jpg
case_images: fig2
case_images: T1-weighted images demonstrated hyperenhancement within the solid component of the mass. This area corresponded to hyperintensity on diffusion-weighted images (DWI) and hypointensity on apparent diffusion coefficient (ADC) maps. The restriction of diffusion to the solid component suggested the possibility of epithelial cancer (Figures 2A-D).
case_images: (A-C) F-18 FDG PET/CT images showed FDG uptake of pelvic tumor (A), left lobe thyroid nodule (B), MIP (C). Microscopy showed a large amount of thyroid tissue, local follicular epithelial cell hyperplasia, consistent with struma ovarii (D). (H and E, x100).
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case_images: PMC11263014_01_fmed-11-1393083-g003.jpg
case_images: fig3
case_images: F-18 FDG PET/CT was used to further characterize the mass and to check for any hypermetabolic activity that might indicate malignancy or metastasis. FDG uptake in the solid component of the pelvis tumour (SUVmax = 6.8) was observed on F-18 FDG PET/CT, left lobe thyroid nodule SUVmax = 4.8 (Figures 3A-C). The postoperative pathological examination reported the presence of abundant thyroid tissue in the left ovary, with local follicular epithelial cell hyperplasia and adenomatous hyperplasia, consistent with a diagnosis of struma ovarii (Figure 3D).