PMC10413121_01
Ultrasound and contrast-enhanced computed tomography (CT) images of myxoid liposarcoma (MLS) of the left kidney invading the pancreas. (A,B) A heterogeneous hypoechoic mass measuring approximately 7.8 cm x 7.0 cm was observed in the upper middle part of the left kidney with indistinct borders. Color Doppler flow imaging (CDFI) revealed the presence of grade II flow signal within the mass. (C,D) Additionally, a cystic solid mass measuring approximately 4.8 cm x 4.4 cm was identified in the posterior part of the pancreas, immediately adjacent to the superior pole of the left kidney. CDFI indicated the presence of grade I blood flow signal within the mass. (E) The arterial phase transverse CT image depicted a protruding mass in the upper middle part of the left kidney, exhibiting extrarenal growth (long arrows), blurring of the perirenal fat gap, and significant enhancement (76 HU). (F) A volume rending (VR) image demonstrated abundant blood supply to the mass, with multiple branches of the left renal artery entering the lesion. (G,H) Coronal and sagittal images obtained from the venous phase displayed invasion of the pancreas by the left kidney mass (98 HU).
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Color Doppler flow imaging demonstrated grade II blood flow signal within the mass (Figures 1A,B). Additionally, a cystic solid mass measuring approximately 4.8 cm x 4.4 cm was detected in the posterior part of the pancreas, located immediately adjacent to the superior pole of the left kidney (Figures 1C,D). The lesion measured approximately 7.0 cm x 9.0 cm x 10.7 cm, showing significant enhancement (Figure 1E). The mass displayed rich blood supply, with visible branches of the left renal artery entering the mass (Figure 1F). Multiplanar reconstruction revealed a connection between the pancreatic lesion and the mass in the left kidney (Figures 1G,H). 18F-FDG PET/CT was conducted for lesion staging, demonstrating a prominent growth of a lesion in the upper middle part of the left kidney, extending beyond the kidney and infiltrating the pancreatic body.
18F-FDG PET/CT images of myxoid liposarcoma of the left kidney invading the pancreas. (A) The anteroposterior 3-dimensional maximum intensity projection image (MIP) revealed increased metabolic activity in the left kidney (long arrows) and the pancreatic body region (dashed arrows). (B) Transverse images exhibited irregular morphology of the left kidney, accompanied by significantly high FDG uptake (SUVmax = 9.3). (C) Transverse images showed a pancreatic body lesion with significantly high FDG uptake (SUVmax = 10.2). (D,E) Coronal and sagittal images demonstrated an extra-renal protrusion of the left renal lesion and invasion of the pancreas.
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The lesion exhibited significantly high FDG uptake (SUVmax = 10.2, MTV = 136.13 cm3, TLG = 484.62) and had a maximum dimension of approximately 6.8 cm x 8.9 cm (Figure 2).
Histopathological and immunohistochemical images. (A) Hematoxylin-eosin (HE) staining (magnification x100) showed a diffuse distribution of tumor cells and a mucus-like stroma, along with a significant presence of proliferating small vessels and abundant cytoplasm. Immunohistochemistry showed that the short spindle cells were positive for MDM2 (B), CD34 (C), Vimentin (D), S-100 (E) and STAT-6 (F) was observed to be positive of the tumor cells (magnification x40 and x200).
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Notably, frequent nuclear atypia and a mucus-like stroma were observed, along with a significant presence of proliferating small vessels and abundant cytoplasm (Figure 3A). Immunohistochemical results exhibited that the MDM2, CD34, Vimentin, S-100, and STAT-6 were positive in tumor cells (Figures 3B-F).
Postoperative contrast-enhanced CT images showed recurrence of MLS. Coronal (A) and sagittal (B) images obtained from the venous phase showed moderate inhomogeneous enhancement of the recurrent tumor in the abdominal cavity with compression and displacement of adjacent organs.
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Subsequent CT examination confirmed tumor recurrence (Figure 4).