Primary Synovial Sarcoma of the Kidney with Inferior Vena Caval Thrombus

Abstract

Synovial sarcomas occurs primarily in the soft tissues, mostly in para-articular regions of the extremities. These tumors have been described in other unusual locations like the pleura, lungs, mediastinum, and kidneys. Primary synovial sarcoma of the kidney is a recently described entity; to date, a total of approximately 35 cases have been reported. Only three cases of primary synovial sarcoma of kidney with IVC thrombus have been reported so far. Here we present the case of a 44 year old gentleman, with primary synovial sarcoma of the left kidney with caval thrombus.Keywords Synovial sarcoma . Renal . Tumors . Kidney . IVC . Thrombus Case SummaryA 44 year old gentleman presented with an incidentally detected left renal mass during routine evaluation. On examination, he had a 7*7 cm mass palpable in the left hypochondrium, which was ballotable. CT and MRI scan of abdomen done elsewhere, revealed a 9*9 cm mass lesion involving the upper pole of the left kidney with associated left renal vein thrombosis. Doppler ultrasound at presentation revealed left renal vein thrombosis with no evidence of Inferior vena cava (IVC) thrombosis. His renal parameters were deranged with blood urea 40 mg/ml and serum creatinine 1.7 mg. Renogram revealed glomerular filtration rate of 17.8 ml/min on the left side and 30.7 ml/min on the right side (Figs. 1, 2, 3 and 4).PET CT scan (done without IV contrast in view deranged renal functions) showed a tumor in the upper pole of the left kidney with tumor thrombus in the left renal vein with a SUV of 9.2. He underwent left radical nephrectomy. Intraoperatively, the thrombus was extending into the infrahepatic inferior vena cava and left lumbar vein. The IVC was mobilised, both renal veins were exposed, and slings were passed around these structures for control, taking care not to dislodge the thrombus. Incision performed at the ostium of the tumoral renal vein and the thrombus was completely removed under direct vision.Grossly there was an ill defined white to brown necrotic tumour 10*8*7 cm, involving almost the entire upper pole and with extension into the midpole. Renal vein was dilated with thrombus and the tumor was covered by a thin capsule with perirenal fat and fascia.Microscopy revealed mult-nodular tumor composed of sheets and intersecting bundles of spindle cells with elongated and pleomorphic vesicular nuclei. Microscopic foci of mucinous area was noted. Mitosis was 2 per high power field. Tumor thrombus was adherant to the lumen of the blood vessel. Lymph nodes around the ureter and para aortic nodes were free of tumour. Overall features were suggestive of malignant spindle cell tumor, high grade.Immunohistochemistry study showed strong positive reaction for Vimentin, EMA, CD 99 and bcl-2. 40 % cells showed strong nuclear positivity for KI 67. The tumor cells showed negative uptake for CD10 and Keratin. Histology along with Immunohistochemistry correlation favored Synovial sarcoma, High grade.

Primary renal synovial sarcoma: A case report

“…At present, it is difficult to differentiate PRSS from other sarcomas in terms of morphology, which can be assessed by examining the expression of combinations of Vimentin, Bcl-2, CD56, CK, SMA, DES, Pax-8, and other markers[10]. In addition, TLE1 antibody can also be used as an important tissue factor to distinguish PRSS from other sarcomas.…”