case_images: PMC4553202_01
case_images: Abdominal CT scans demonstrating a 20 cm mass in the left upper quadrant retroperitoneum.
case_images: CRIPA2015-241308.001.jpg
case_images: PMC4553202_01_CRIPA2015-241308.001.jpg
case_images: fig1
case_images: A 64-year-old male presented with persistent abdominal pain, and on imaging, he was found to have a 20 cm abdominal mass causing mass effect on the stomach, pancreas, left adrenal gland, and kidney (Figure 1).
case_images: Microscopic examination of the retroperitoneal mass. There were sheets of undifferentiated cells with no papillary architecture seen ((a) 100x). The malignant cells had rhabdoid features with abundant granular eosinophilic cytoplasm, eccentric, vesicular nuclei, and prominent nucleoli. Mitoses were readily identified ((b) 400x).
case_images: CRIPA2015-241308.002.jpg
case_images: PMC4553202_01_CRIPA2015-241308.002.jpg
case_images: fig2
case_images: Mitoses were readily identified (Figure 2).
case_images: Immunohistochemical features of the tumor cells. The tumor cells showed diffuse positivity for AE1/AE3 (a), galectin-3 (b), and PAX-8 (c). There was patchy positivity for p53 (d). The tumor cells showed only weak focal positivity for TTF-1 (e) and were negative for thyroglobulin (f). All photographs at 400x magnification.
case_images: CRIPA2015-241308.003.jpg
case_images: PMC4553202_01_CRIPA2015-241308.003.jpg
case_images: fig3
case_images: The tumor cells were strongly positive for AE1/AE3, galectin-3, PAX8 (Figures 3(a)-3(c)), and vimentin, with patchy positivity for p53 (Figure 3(d)). TTF-1 (Figure 3(e)), CK7, CK19, and S100. Thyroglobulin (Figure 3(f)), HBME-1, CK20, OCT3/4, CD117, CD45, and HMB45 were negative (Ventana Medical Systems, Tucson, AZ).