case_images: PMC8416087_01
case_images: CT and MRI images of the mass. The preoperative transverse view reveals that the tumor was located in the lower segment of the right ureter (A). CT scan reveals local relapse in the tumor bed with infiltration to the surrounding tissues (white arrow, B). Left inguinal lymphadenopathy (2.1x1.5 cm, white triangle, B). Coronal and transverse views show a progressive SCNEC with multiple liver (C, D), bilateral pubic bones (E), and right acetabulum (F) metastases after 2 cycles of durvalumab.
case_images: fonc-11-696422-g001.jpg
case_images: PMC8416087_01_fonc-11-696422-g001.jpg
case_images: f1
case_images: Abdominal and pelvic contrast-enhanced computed tomography (CT) scan revealed a large mass, measuring about 5 cm in the distal right ureter with moderate right hydroureterosis (Figure 1A). Pelvic CT scan showed an 8.2x6.8 cm mass infiltrating bladder wall without clear margins to the surrounding tissues (Figure 1B). A left inguinal lymphadenopathy measured 2.1x1.5 cm was suspected with metastasis (Figure 1B). However, MRI and CT scan showed bilateral pubic bones (Figure 1E), right acetabulum (Figure 1F), and liver metastases (Figures 1C, D).
case_images: Microscopic findings and immunohistochemical staining. Low (A; magnification, x100) and high (B; x200, C; x400) power showed the SCNEC (hematoxylin and eosin staining). The tumor is composed of small round cells which had enormous hyperchromatic nuclei and limited cytoplasm with a high nuclear/cytoplasmic ratio (C). Positive immunohistochemical staining for chromogranin-A (D), CD56 (E), synaptophysin (F) and CK (G). Negative immunohistochemical staining for GATA-3 (H). The Ki-67 index was 80% (I). CgA, chromogranin-A; Syn, synaptophysin; CK, cytokeratin; GATA-3, GATA binding protein 3.
case_images: fonc-11-696422-g002.jpg
case_images: PMC8416087_01_fonc-11-696422-g002.jpg
case_images: f2
case_images: Microscopic examination revealed that the tumor was composed of small round cells which had enormous hyperchromatic nuclei and limited cytoplasm with a high nuclear/cytoplasmic ratio (Figures 2A-C). Upon immunohistochemical test, the neuroendocrine markers (chromogranin-A, synaptophysin, and CD56), and epithelial markers (CK) were positive in the small round tumor cells (Figures 2D-G), while negative for urothelial markers (GATA-3) (Figure 2H). The mitotic count was high, and the proliferative index counted by Ki-67 was 80% (Figure 2I).