PMC6106707_01
CT and FDG-PET/CT images of the pelvic paraganglioma and lymph node metastasis of the patient, a 17-year-old female. Axial CT images showed a hypervascular well-defined and lobulated mass (55 mm in long dia.) located dorsocaudal to the urinary bladder (A) and enhanced lymph node swelling (15 mm in short dia.) at the right internal obturator region (B, red arrow). C,D: Intensely high FDG accumulation in the tumor and the lymph node with SUVmax values of 24.7 and 20.8, respectively.
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Axial CT images showed a hypervascular well-defined and lobulated mass (55 mm in long dia.) located dorsocaudal to the urinary bladder (Fig. 1A) and intensely enhanced lymph node swelling (15 mm in short dia.) at the right internal obturator region (Fig. 1B). Intense FDG uptake was observed in the tumor and right internal obturator lymph node with maximum standardized uptake (SUVmax) values of 24.7 and 20.8, respectively (Fig. 1C, D).
CT and FDG-PET/CT images of activated mesenteric BAT. A: Axial non-contrast-enhanced CT showed increased attenuation of the visceral fat tissues. Contrast-enhanced CT showed early enhanced (B) and delayed washed out (C) and a spaghetti-like appearance in the mesentery. Intense FDG accumulation in the mesentery was observed (D, SUVmax = 8.1).
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CT showed increased attenuation of the visceral fat tissues in the parahepatic, paranephric, periadrenal, and mesenteric areas. Contrast-enhanced CT showed thickened mesenterium with dilated mesenteric vasculatures, with a "spaghetti-like" appearance (Fig. 2A-C). The FDG uptake in the mesenteric fat was so high (SUVmax = 8.1) that the possibility of tumor dissemination could not be denied (Figs. 2D, 3 A).
Pre- and post-surgery FDG-PET MIP images. A: Pre-surgery MIP images showed FDG accumulation of BAT in almost the entire body. B: Almost all of the FDG accumulations except for a urinary extravasation (*) had disappeared after the surgery.
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Moreover, a whole-body maximum intensity projection (MIP) image showed FDG accumulation in almost the entire body adipose tissue, including the lateral neck, supraclavicular, shoulders, axillary, mediastinum, intercostal paravertebral area, parahepatic area, retroperitoneum including paranephric and periadrenal areas, and mesentery (Fig. 3A). The FDG uptake in the mesenteric fat was so high (SUVmax = 8.1) that the possibility of tumor dissemination could not be denied (Figs. 2D, 3 A).
Pathology of the pelvic paraganglioma. Macroscopic (A) and microscopic features of the pelvic paraganglioma are shown. H&E staining showed atypical cells with stippled chromatin arranged in cell nests (B). Immunohistochemistry showed positivity for chromogranin (C) and synaptophysin (D).
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A brownish and oval tumor was located behind the urinary bladder (Fig. 4A). Hematoxylin-eosin staining showed atypical cells with stippled chromatin arranged in cell nests (Fig. 4B). Both chromogranin (Fig. 4C) and synaptophysin (Fig. 4D) immunohistochemistry stains were positive. A post-surgery FDG-PET/CT examination indicated no abnormal FDG uptake but a little amount of urinary extravasation at the right side of the bladder (Fig. 4B).