PMC6880134_01
CT and FDG-PET findings. (a-b) CT showing a relatively well-circumscribed, heterogeneously enhanced round mass measuring 25 mm [a) 3 years previously and b) before the present surgery]. (c) FDG-PET showing a slight uptake in the splenic lesion; no other significant findings indicated recurrence at other sites.
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A heterogeneously enhanced round mass measuring 25 mm was detected in the spleen (Fig. 1), and no mass was detected in the thyroid. Ultrasonography revealed microcalcification (26 x 16 mm2) along the vessel wall within the lesion; it also revealed that the lesion was poorly marginated (Fig. 3). 18F-2-fluoro-2-deoxyglucose-positron emission tomography revealed a slight uptake in the splenic lesion; otherwise, there were no significant findings indicating recurrence at other sites (Fig. 1).
MRI findings. MRI showing a heterogeneous low intensity region within the lesion, indicating fibrosis or hemosiderin, on a T2-weighted image. a) The lesion showed iso-intensity in the spleen, and dynamic study showed gradual enhancement of the lesion [b) 0 s, c) 30 s, d) 180 s] characterized as a "spoke-wheel pattern" on a T1-weighted image.
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Dynamic study showed gradual enhancement of the lesion (Fig. 2).
Ultrasonography findings. Ultrasonography revealed microcalcification within the lesion measuring 26 x 16 mm2 and calcification along the vessel wall with a poorly marginated lesion.
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Ultrasonography revealed microcalcification (26 x 16 mm2) along the vessel wall within the lesion; it also revealed that the lesion was poorly marginated (Fig. 3). 18F-2-fluoro-2-deoxyglucose-positron emission tomography revealed a slight uptake in the splenic lesion; otherwise, there were no significant findings indicating recurrence at other sites (Fig. 1).
Pathological findings. (a) Macroscopically, a dark-reddish nodular lesion measuring 23 x 20 x 15 mm3 with a color similar to that of the background spleen was observed. b) Histopathological examination showing a well-circumscribed lesion mainly composed of a red pulp-like structure with irregular fibrosis in the stroma. c-e) Immunohistochemistry showing coexistence of three types of vessels (capillary of CD34+/CD8-/CD31+, splenic sinusoid-like vessels of CD34+/CD8-/CD31+, and small vein of CD34+/CD8-/CD31+).
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The resected specimen had a dark-reddish nodular lesion measuring 23 x 20 x 15 mm3 (Fig. 4). The histopathological examination revealed a well-circumscribed lesion mainly comprising a red pulp-like structure with irregular fibrosis in the stroma (Fig. 4). Immunohistochemistry revealed the coexistence of three types of vessels (capillary of CD34+/CD8-/CD31+, splenic sinusoid-like vessels of CD34+/CD8-/CD31+, and small vein of CD34+/CD8-/CD31+) (Fig. 4).