Primary mesenchymal chondrosarcoma of the kidney with synchronous implant and infiltrating urothelial carcinoma of the ureter

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1522835667751019Mesenchymal chondrosarcoma was first reported by Lichtenstein and Bernstein in 1959 [1]. This malignant tumor mostly arises in the skeleton, and one third of the cases arise in the soft tissue and other organs. Extraskeletal mesenchymal chondrosarcoma is rare, and uaually arises in the head and neck region, followed by the lower extremity, the trunk and the retroperitoneum. Primary mesenchymal chondrosarcoma of the kidney is extremely rare, and the first case was published 25？years ago by Malhotra [2]. To date, there are only seven cases of primary renal chondrosarcoma reported in the English literature [2-7]. We report another case of mesenchymal chondrosarcoma of the kidney with synchronous implant and a coexistent infiltrating urothelial carcinoma of the ureter firstly.A 64-year-old man presented with gross hematuria and vague pain in the left loin. His medical history was unremarkable. Physical examination revealed percussion pain over the left kidney region. Urinalysis showed positive for protein and red blood cells. Abdominal B ultrasonography revealed left hydronephrosis and a hypoechoic mass in the inferior segment of the left ureter. Magnetic resonance imaging (MRI) confirmed left hydronephrosis, a low signal mass in the upper pole of the kidney, and another mass with high T1, low T2 signal in the inferior segment of the left ureter. Imaging examination showed no abnormality elsewhere. A clinical diagnosis of malignancy of the left kidney and the ureter was made, for which a left nephro-ureterectomy was performed.Gross examination of the nephro-ureterectomy specimen showed pale grayish solid tumor in the enlarged kidney, and the tumor measured 11？×？8？×？6？cm, causing dilatation of the renal pelvis. The tumor invaded the cortex, medulla, adeps renis and involved 90% of the total kidney, resulting in distortion (Figure 1a). And a separate elon