PMC4881246_01
a CT scan with contrast demonstrating a large saddle filling defect. b PET-CT scan of the chest showing intense uptake in the mediastinum, hilar lymph nodes, and right thyroid. c Repeat CT scan of the chest with and without contrast after six courses of chemotherapy. d Repeat PET-CT scan showing resolution of intense FDG uptake after six courses of chemotherapy.
cro-0009-0267-g01.jpg
PMC4881246_01_cro-0009-0267-g01.jpg
F1
The PET scan revealed intense uptake in the right lateral cervical, mediastinal, and hilar lymph nodes (fig. 1b). A CT scan with contrast revealed a large saddle filling defect extending into the right and left pulmonary arteries as well as the proximal bilateral upper and lower lobe pulmonary artery branches (fig. 1a). As seen in figure 1c, the images showed no intraluminal masses in the pulmonary arterial branches. A PET-CT was repeated and showed resolution of intense FDG uptake in the region of the pulmonary arteries, compatible with complete response to treatment (fig. 1d).
a H&E staining at low magnifiation. b, c H&E staining at higher magnification. d-f CD31 IHC stain showing a blood vessel (strongly CD31 positive) surrounded by weakly staining sarcoma cells indicative of vascular differentiation.
cro-0009-0267-g02.jpg
PMC4881246_01_cro-0009-0267-g02.jpg
F2
Immunohistochemical analysis and staining (fig. 2) was positive for smooth muscle actin and positive for CD31 (a marker of endothelial/vascular differentiation).