case_images: PMC8387077_01
case_images: A - Axial; and B - Coronal contrast enhanced CT abdomen reveal nodular, polypoidal enhancing mass (white arrow) arising from right posterior wall of urinary bladder.
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case_images: The abdominal and pelvic contrast-enhanced computed tomography (CT) revealed a nodular and polypoidal enhancing mass from the right posterior wall of the urinary bladder (Figure 1).
case_images: A - Photomicrograph showing a tumor arranged in nests and trabeculae separated by thin fibrovascular septae, with 'Zellballen pattern' (H&E 100X); B - On IHC, the tumor cells are positive for chromogranin (100X); and C - synaptophysin (100X); D - S100 protein is expressed by sustentacular cells at the periphery of the cell nests (400X).
case_images: autopsy-11-e2021305-g02.jpg
case_images: PMC8387077_01_autopsy-11-e2021305-g02.jpg
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case_images: Sections showed the bladder, focally lined by urothelial lining, with a tumor in the lamina propria, arranged in nests and trabeculae separated by thin fibrovascular septae, with 'Zellballen pattern' (Figure 2A). S100 protein was positive in the periphery of the nests in the sustentacular cells (Figures 2B-D).
case_images: PMC8387077_02
case_images: B - Coronal contrast-enhanced CT images arterial phase showing lobulated enhancing bladder mass (thick arrows), venous phase CT images showing paravesical extension (black arrows) with bulky retroperitoneal and abdominal lymphadenopathy (arrowheads) and multiple liver metastases (white arrows).
case_images: autopsy-11-e2021305-g03.jpg
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case_images: A - Photomicrograph showing a tumor with cells having high nuclear-cytoplasmic ratio and hyperchromatic nuclei arranged in diffuse sheets, H&E 400X; B - The tumor cells show partial cytoplasmic granular positivity for chromogranin, 400X; C - The tumor cells are negative for LCA, 400X; D - The Ki-67 proliferation index of the tumor is very high, 99% (400X).
case_images: autopsy-11-e2021305-g04.jpg
case_images: PMC8387077_02_autopsy-11-e2021305-g04.jpg
case_images: gf04
case_images: Sections from the lesion showed a proliferation of tumor cells arranged in sheets and nests, with moderately pleomorphic small cells, with scant cytoplasm, hyperchromatic round to overlapping oval nuclei, and inconspicuous nucleoli (Figure 4A). On IHC, the tumor cells were positive for neuroendocrine markers, chromogranin (Figure 4B), and synaptophysin. The tumor cells were negative for LCA, ruling out the differential diagnosis of lymphoma (Figure 4C). Ki-67 labeling index was 99% (Figure 4D).