case_images: PMC4996605_01
case_images: CT scan of the abdomen and pelvis without contrast in (A) coronal imaging and (B) axial imaging. The right kidney is enlarged containing a large amount of gas within the parenchyma and collecting system with a staghorn calculus in the renal pelvis measuring >3 cm (white arrows).
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case_images: f1
case_images: A CT scan of the abdomen and pelvis was obtained which showed a large amount of gas within the parenchyma and collecting system of an enlarged right kidney, consistent with EPN (Fig. 1).
case_images: Gross appearance of kidney that has been largely destroyed by a necrotic abscess and tumor centrally (black circle with white edges). More viable tumor is seen peripherally as solid tan nodules (black arrow). A small amount of normal renal cortex and medulla remain (black star).
case_images: fig-2.jpg
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case_images: f2
case_images: Upon gross examination of the specimen, normal parenchyma had been replaced by a large, friable necrotic mass, measuring 10 cm, and the pelvocaliceal system could not be identified (Fig. 2).
case_images: (A) Microscopic appearance of squamous cell carcinoma transitioning to an area of poorly differentiated sarcomatoid carcinoma. (B) High power magnification demonstrating hyperchromatic and pleomorphic spindle cells representing sarcomatoid carcinoma.
case_images: fig-3.jpg
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case_images: f3
case_images: Histologic sections of the pelvis showed remnants of pelvocaliceal lining with squamous carcinoma in situ transitioning to invasive SCC (Fig. 3A). Multiple areas of the tumor also demonstrated poorly differentiated sarcomatoid features, composed of hyperchromatic and pleomorphic spindle cells (Fig. 3B).