case_images: PMC10803445_01
case_images: Female, 67 years old, primary sacral synovial sarcoma. (A) Axial CT. (B) Coronal CT. (C) Axial CT. (D) Sagittal CT. CT scan showed expansive bone destruction in the S1-3 vertebrae with soft tissue density of about 58 mm x 46 mm x 52 mm. The boundary was not clear, calcification (arrow, A) and necrosis (arrow, B) were visible within the vertebrae, and the boundary between the mass and the anterior sacral blood vessels and rectum was unclear.
case_images: fonc-13-1309123-g001.jpg
case_images: PMC10803445_01_fonc-13-1309123-g001.jpg
case_images: f1
case_images: Non-contrast CT scan ( Figure 1 ) showed expansive bone destruction in the S1-3 vertebrae with soft tissue density of about 58 x mm 46 x mm 52 mm.
case_images: Female, 67 years old, primary sacral synovial sarcoma. (A) T1-weighted images. (B) T2-weighted images. (C) Axial: T1 arterial stage 20s. (D) Sagittal: T1 arterial stage 20s. MRI plain scan showed mixed signals in lumbosacral masses, with equal signals in T1 (arrow, A) and uneven and slightly higher signals in T2. Cystic degeneration and necrosis were visible, with multiple compartments in the lumbosacral masses (arrow, B). MRI enhancement showed uneven enhancement of lumbosacral mass with multiple compartments and no enhanced cystic lesion (arrow, C).
case_images: fonc-13-1309123-g002.jpg
case_images: PMC10803445_01_fonc-13-1309123-g002.jpg
case_images: f2
case_images: Non-contrast MRI scan ( Figure 2 ) showed mixed signals in lumbosacral masses, with equal signals in T1 and uneven and slightly higher signals in T2.
case_images: Female, 67 years old, primary sacral synovial sarcoma. One hour after injection of 18F-FDG into PET/CT: (A) axial CT, (B) axial PET, (C) axial fusion, and (D) whole-body maximum intensity projection (MIP). PET/CT showed that S1-3 vertebral body and left sacral alar bone were destroyed and soft tissue shadow formed, invading the sacral canal and the left foramina of S1-3, necrosis and separation were visible within the mass, no significant FDG uptake was found in the necrotic area (arrow, B), FDG metabolism was significantly increased in the rest of the mass, and SUVmax was 4.9 (arrow, C).
case_images: fonc-13-1309123-g003.jpg
case_images: PMC10803445_01_fonc-13-1309123-g003.jpg
case_images: f3
case_images: Figure 3 ) showed that S1-3 vertebral body and left sacral alar bone were destroyed and soft tissue shadow were formed, invading the sacral canal and the left foramina of S1-3, and there are no signs of local dissemination along sacral nerves. FDG metabolism was significantly increased, and malignant tumor was diagnosed by PET/CT.
case_images: Female, 67 years old, primary sacral synovial sarcoma. (A) H-E x 40, (B) H-E x 100, (C) H-E x 200, and (D) H-E x 400. H-E staining showed that the epithelioid structure and sarcomatoid components could be seen under the microscope, the sarcomatoid components contained abundant spindle forming fibrocytes and increased interstitial blood vessels, and cystic necrosis areas could be seen, without calcification and ossification.
case_images: fonc-13-1309123-g004.jpg
case_images: PMC10803445_01_fonc-13-1309123-g004.jpg
case_images: f4
case_images: Because there was no obvious metastasis in the whole body and the preoperative diagnosis was not clear, surgical resection was given. hematoxylin-eosin (H-E) staining ( Figure 4 ) showed that the epithelioid structure and sarcomatoid components could be seen under the microscope, the sarcomatoid components contained abundant spindle forming fibrocytes and increased interstitial blood vessels, and cystic necrosis areas could be seen, without calcification and ossification.