case_images: PMC10508336_01
case_images: Pelvic contrast-enhanced MRI images and pathological images of the testicular teratoma. Pelvic contrast-enhanced MRI revealed that the left testicular mass contained both solid and cystic components, and it exhibited low signal intensity on T1WI transverse image (A), and high signal intensity on T2WI transverse image (B). There were multiple reticular structures in the mass, which exhibited low signal intensity on T1WI and T2WI, and exhibited high signal intensity on DWI transverse image (C). On enhancement scan image (D), the solid components showed significant enhancement. (E-G) The hematoxylin-eosin (HE) staining (magnification x40 and 100) showed that the mature teratoma was infiltrated with mostly well-differentiated tissues, while focal areas showed markedly heterotypic epithelioid cells. (H) Immunohistochemistry showed that the tumor cells were positive for SALL4 (magnification x100).
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case_images: PMC10508336_01_fmed-10-1269587-g001.jpg
case_images: fig1
case_images: And there were no enlarged lymph nodes in the scanning range (Figures 1A-D). Immunohistochemistry staining results demonstrated the positive expression of AE1/AE3, SALL4, CK7 and Ki-67 (20%), whereas the negative expression of CD30, EMA, CEA, PLAP, AFP2, Vim, CD117, S-100, TTF1, PSA, CK20 (Figures 1E-H).
case_images: Contrast-enhanced CT and 18F-FDG PET/CT images. The retroperitoneal teratoma exhibited an incomplete capsule and unclear local boundaries on the enhanced CT plain scan (A), with uneven internal density. And it demonstrated uneven enhancement during the arterial (B) and venous (C) phases of the contrast-enhanced CT. (D) The whole-body maximum intensity projection showed the retroperitoneal lesion with hypermetabolism. The transverse (E), coronal (F) and sagittal (G) images of retroperitoneal lesions showed that the tumor had high FDG uptake, with a SUVmax of 15.9.
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case_images: fig2
case_images: Also, the fatty space surrounding the lesion was unclear and the lesion demonstrated uneven enhancement (Figures 2A-C). In addition, there were no metastatic lesions with abnormal FDG uptake in other parts of the body (Figures 2D-G).
case_images: 18F-FDG PET/CT images before and after chemotherapy. Before the patient received chemotherapy, the whole-body maximum intensity projection (A) showed multiple hypermetabolic lesions around the abdominal aorta, spleen, left psoas major, left diaphragm foot and left pelvic cavity. And the transverse images (B,C) showed that these lesions had significantly increased FDG uptake, with a SUVmax of 22.5. After the patient received a cycle of chemotherapy, the whole-body maximum intensity projection (D) and the transverse images (E,F) showed that the pre-existing lesions shrank or disappeared, and the remaining lesions displayed a marked reduction in FDG uptake compared to before.
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case_images: fig3
case_images: The FDG uptake of these lesions increased unevenly, with a SUVmax of 22.5, indicating extensive recurrent metastasis of the tumor (Figures 3A-C). FDG uptake was lower than before with a SUVmax of 8.4. Furthermore, the PET/CT results after chemotherapy showed that most of the lesions became smaller or disappeared, and FDG uptake became normal, achieving complete metabolic response recovery and suggesting that the treatment was effective (Figures 3D-F).