case_images: PMC10583509_01
case_images: Chest images. (a) Chest X-ray showed a huge mass-like opacity in the right thoracic cavity (arrow). (b) CT scan revealed a large (24 x 15 x 24 cm) mass that occupied the posterior mediastinum, further extended into the right thoracic cavity and compressed the lower lobes of both lungs into atelectasis; the diaphragm was also obviously compressed and moved down.. CT: computed tomography.
case_images: 10.1177_2050313X231206031-fig1.jpg
case_images: PMC10583509_01_10.1177_2050313X231206031-fig1.jpg
case_images: fig1-2050313X231206031
case_images: Chest X-ray showed a huge mass-like opacity in the right thoracic cavity (Figure 1(a)). The diaphragm was also compressed and moved down (Figure 1(b)).
case_images: Gross appearance of the resected tumor. Grossly, there was an irregular mass with a size of 25 x 18 x 13 cm. The cut surface of the excised tumor was multinodular with a diameter of 2-15 cm, which was a well-defined gray-yellow solid part or gray-red solid translucent part.
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case_images: PMC10583509_01_10.1177_2050313X231206031-fig2.jpg
case_images: fig2-2050313X231206031
case_images: Grossly, there was an irregular mass with a size of 25x18x13 cm, and the cut surface of the excised tumor was multinodular with a diameter of 2-15 cm, with a well-defined gray-yellow solid part or gray-red solid translucent part (Figure 2).
case_images: Well-differentiated components were found morphologically. The adipocytes varied in size, and atypical interstitial cells were observed within the fibrous septum. (a) H&E, x100. (b) H&E, x200. Dedifferentiated components were found morphologically. Morphology revealed that fibroblast-like cells were predominant with relatively low density and myxoid degeneration of the interstitium was observed with plexiform microvascular structure. A few fat vacuoles were present focally; nuclear atypia is mild to moderate; mitotic figures were less than 5/10 HPF; and necrosis was rare. (c) H&E, x200. (d) H&E, x400.. H&E: hematoxylin-eosin; HPF: high-power field.
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case_images: PMC10583509_01_10.1177_2050313X231206031-fig3.jpg
case_images: fig3-2050313X231206031
case_images: For example, the adipocytes varied in size, and atypical interstitial cells were observed within the fibrous septum (Figure 3(a) and (b)). A few fat vacuoles were present focally, nuclear atypia was mild to moderate, the mitotic rate was less than 5 per 10 high-power fields, which was classified as French Federation of Cancer Centers grade 2, and necrosis was rare (Figure 3(c) and (d)).
case_images: IHC and FISH findings of the tumor. Positive immunoreactions for CDK4 (a), MDM2 (b), Ki-67 (c), P16 (d), and S-100 (e) in the nuclei of tumor cells, in addition, (f) FISH analysis identified MDM2 amplification, confirming the diagnosis of DDL.. DDL: dedifferentiated liposarcoma; IHC: immunohistochemistry; FISH: fluorescence in situ hybridization; CDK4, cyclin-dependent kinase 4; MDM2, murine double minute 2.
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case_images: PMC10583509_01_10.1177_2050313X231206031-fig4.jpg
case_images: fig4-2050313X231206031
case_images: MUC-4(-). Moreover, MDM2 gene amplification was positive by fluorescence in situ hybridization (FISH; Figure 4(f)).