Carcinosarcoma of the Ureter with a Small Cell Component: Report of a Rare Pathologic Entity and Potential for Diagnostic Error on Biopsy

Figure 1

Histologic appearance of carcinosarcoma of the ureter. (a) Biopsy demonstrating poorly differentiated, dark blue cell tumor with marked crush artifact (5x, H&E). (b) Ureterectomy specimen demonstrating tumor obliterating the ureter lumen with high grade chondrosarcoma component (5x and insert 20x, H&E). (c) Ureter with urothelial carcinoma in situ (20x, H&E). (d, e) Small cell carcinoma component in carcinosarcoma showing strong and diffuse immunoreactivity with CD56 (e) (20x, H&E and 10x, IHC).

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