case_images: PMC11828642_01
case_images: Histopathologic images of sigmoid colon paraganglioma (PGL). (
  A
  ) Tumor with an organoid and nested architecture within the colonic muscularis propria. (
  B
  ) The tumor is composed of uniform cells with salt and pepper chromatin and abundant eosinophilic cytoplasm. Immunohistochemistry images reveal (
  C
  ) strong positivity for chromogranin and (
  D
  ) diffuse nuclear GATA3 positivity, suggestive of sigmoid colon PGL.
case_images: 10-1055-s-0044-1791819-i2480006-1.jpg
case_images: PMC11828642_01_10-1055-s-0044-1791819-i2480006-1.jpg
case_images: FI2480006-1
case_images: It also showed loss of succinate dehydrogenase B (SDH-B) expression ( Fig. 1C, D ).
case_images: 68
  Ga-DOTATATE positron emission tomography (PET)/computed tomography (CT) scans at (
  A
  ) baseline, (
  B
  ) post four cycles of peptide receptor radionuclide therapy (PRRT), and (
  C
  ) post six cycles of PRRT. Upper panel: maximum intensity projection (MIP) images; lower panel: fused axial images of PET/CT. Intense somatostatin receptor (SSTR) expression was noted in abdominopelvic nodes, dorsal and lumbar vertebral lesions, and a large segment VI hepatic lesion at baseline scan, post-four-cycle scan, and post-six-cycle scan. Stable disease was seen in (
  A
  ) and (
  B
  ). Post six cycles, heterogenous decreased SSTR expression was observed along with the appearance of new lesions in (
  B
  ) and (
  C
  ;
  blue arrow
  ). Axial fusion images (lower row) showed lumbar vertebral lesion (L4;
  green arrow
  ) at baseline (
  A
  ), stable SSTR expression post four cycles (
  B
  ), heterogenous decreased SSTR expression along with pathological compression fracture post six cycles (
  star
  ;
  C
  ).
case_images: 10-1055-s-0044-1791819-i2480006-2.jpg
case_images: PMC11828642_01_10-1055-s-0044-1791819-i2480006-2.jpg
case_images: FI2480006-2
case_images: Fig. 2A . For further characterization of these lesions, the patient underwent fluorine-18 fluorodeoxyglucose ( 18 F-FDG) PET/CT scan, which showed intense 18 F-FDG uptake in concordant lesions as shown in Fig. 3A , which was expected as she showed loss of SDH-B expression on immunohistochemistry (IHC) . Dual tracer PET/CT evaluation showed stable disease on comparison as shown in Figs. 2A , B and 3A, B . Dual tracer PET/CT evaluation showed new peritoneal, skeletal lesions (D5 vertebra, left acetabulum) and increase in the size of the hepatic lesion, suggestive of disease progression as shown Figs. 2B, C and 3B, C .
case_images: Fluorine-18 fluorodeoxyglucose (
  18
  F-FDG) positron emission tomography (PET)/computed tomography (CT) scans at (
  A
  ) baseline, (
  B
  ) post four cycles of peptide receptor radionuclide therapy (PRRT), and (
  C
  ) post six cycles of PRRT. Upper panel: maximum intensity projection (MIP) images. Lower panel: fused axial images of PET/CT. MIP images showed intense
  18
  F-FDG uptake in abdominopelvic nodes, dorsal and lumbar vertebral lesions, and a large segment VI hepatic lesion. PET/CT images (
  A, B
  ) showed stable disease. Post six cycles, FDG-PET/CT scan (
  C
  ) showed the appearance of new lesions (
  black arrow
  ) suggestive of disease progression, and pathological compression fracture of the L4 vertebra was noted (
  star
  ).
case_images: 10-1055-s-0044-1791819-i2480006-3.jpg
case_images: PMC11828642_01_10-1055-s-0044-1791819-i2480006-3.jpg
case_images: FI2480006-3
case_images: Fig. 2A . For further characterization of these lesions, the patient underwent fluorine-18 fluorodeoxyglucose ( 18 F-FDG) PET/CT scan, which showed intense 18 F-FDG uptake in concordant lesions as shown in Fig. 3A , which was expected as she showed loss of SDH-B expression on immunohistochemistry (IHC) . Dual tracer PET/CT evaluation showed stable disease on comparison as shown in Figs. 2A , B and 3A, B . Dual tracer PET/CT evaluation showed new peritoneal, skeletal lesions (D5 vertebra, left acetabulum) and increase in the size of the hepatic lesion, suggestive of disease progression as shown Figs. 2B, C and 3B, C .
case_images: PMC11828642_02
case_images: (
  A
  ) Magnetic resonance imaging (MRI) and
  68
  Ga-DOTATATE positron emission tomography (PET)/computed tomography (CT) scan at baseline. Axial MRI (upper) and sagittal (lower) images showed ill-defined short tau inversion recovery (STIR) hyperintense lesion with postcontrast enhancement (
  red arrow
  ), focal infiltration of the bladder wall, and enlarged pelvic nodal masses (
  star
  ) showing similar characteristics to the primary lesion. (
  B
  ) Maximum intensity projection (MIP) image and (
  C
  ) axial and sagittal images showed increased somatostatin receptor (SSTR) expression in hyperenhancing lesion in the posterior and posterolateral walls of the urinary bladder (
  red arrow
  ) and metastatic iliac nodes (
  star
  ; right > left).
case_images: 10-1055-s-0044-1791819-i2480006-4.jpg
case_images: PMC11828642_02_10-1055-s-0044-1791819-i2480006-4.jpg
case_images: FI2480006-4
case_images: T2 hyperintense lesion in the right half of the bladder base measuring 2 x 2 x4.6 cm and T2 hyperintense lesion in the bilateral pelvic nodes measuring 4.5 x 2.5 cm suggestive of metastatic PGL as shown in Fig. 4A , and her urinary catecholamine level was elevated (300 pg/mL). The patient underwent 68 Ga-DOTATATE PET/CT scan, which showed intense SSTR expression in the urinary bladder lesion and the pelvic lymph nodes as shown in Fig. 4B, C . She underwent uterus-, ovary-, and vagina-sparing radical cystectomy with formation of
case_images: Histological images of a urinary bladder paraganglioma (PGL). (
  A
  ) Images showed the nesting and zellballen architecture of the tumor in 100x optical magnification, hematoxylin and eosin (H&E) stain. (
  B
  ) The 200x optical magnification of H&E-stained slide image showed the cellular details with eosinophilic to vacuolated cytoplasm of the tumor cells with tumor cells showing conspicuous nucleoli. (
  C
  ) The lymph node lesion images showed metastases (M) of the same tumor in H&E stain, 20x optical magnification. (
  D
  ) High magnification (200x) of the same nodal metastases with similar tumor morphology as seen in the urinary bladder tumor, suggestive of urinary bladder PGL with lymph nodal metastases.
case_images: 10-1055-s-0044-1791819-i2480006-5.jpg
case_images: PMC11828642_02_10-1055-s-0044-1791819-i2480006-5.jpg
case_images: FI2480006-5
case_images: PGL infiltrating the lamina propria and detrusor muscle with overlying urothelium free of tumor and metastatic PGL in locoregional nodes shown in Fig. 5 . Postsurgery, her PFNM was 5.84 pg/mL.
case_images: 68
  Ga-DOTATATE positron emission tomography (PET)/computed tomography (CT) scans at (
  A
  ) baseline and (
  B
  ) post four cycles of peptide receptor radionuclide therapy (PRRT). Upper panel: maximum intensity projection (MIP) images; lower panel: fused axial images of PET/CT. Increased somatostatin receptor (SSTR) expression was seen in enlarged pelvic nodes and sclerotic sternal lesion at baseline (
  A
  ). Post four cycles of PRRT, PET/CT images showed decreased SSTR expression and size of pelvic lymph nodes and sternal lesion. SUVmax, maximum standardized uptake value.
case_images: 10-1055-s-0044-1791819-i2480006-6.jpg
case_images: PMC11828642_02_10-1055-s-0044-1791819-i2480006-6.jpg
case_images: FI2480006-6
case_images: SSTR expressing sclerotic sternal and calvarial lesions as shown in Fig. 6A . After four cycles, her PFMN was raised to 62.9 pg/mL, but imaging evaluation showed no new lesions, suggestive of stable disease as shown Fig. 6B .
case_images: PMC11828642_03
case_images: 68
  Ga-DOTATATE positron emission tomography (PET)/computed tomography (CT) scans at (
  A, B
  ) baseline and (
  C, D
  ) post four cycles of peptide receptor radionuclide therapy (PRRT). Maximum intensity projection (MIP) image and fused axial images of PET/CT scan showed intense somatostatin receptor (SSTR) expression in residual carotid body bladder paraganglioma, intense SSTR expression in multiple hepatic lesions, and skeletal lesions at baseline. Post four cycles of PRRT, the MIP and fused axial images of PET/CT scan showed a reduction in SSTR uptake, size and number of carotid body lesion, and hepatic and skeletal lesions suggestive of a favorable response to PRRT. SUVmax, maximum standardized uptake value.
case_images: 10-1055-s-0044-1791819-i2480006-7.jpg
case_images: PMC11828642_03_10-1055-s-0044-1791819-i2480006-7.jpg
case_images: FI2480006-7
case_images: SSTR uptake in the residual carotid body lesion, multiple liver lesions, and sclerotic skeletal lesion with lung nodules as shown in Fig. 7A, B . Subsequently, the patient received four cycles of 177 Lu-DOTATATE PRRT. After four cycles of PRRT, 68 Ga-DOTATATE PET/CT scan showed decreased SSTR expression in the residual carotid and liver lesions, and decreased in number and size of liver lesions, suggestive of a favorable response to PRRT as shown in Fig. 7C, D .