A Potential Link: Cross-fused Renal Ectopia With Concomitant Absent Left Testicle.

Cross-fused renal ectopia (CFRE) is a rare congenital anomaly in which both kidneys are located on a unilateral side of the retroperitoneal space. The ureter of the ectopic kidney is seen to pass over the midline to insert in its normal anatomic position. Frequently this anomaly goes undetected until there is radiologic screening for other purposes or when other genitourinary issues are investigated. Although frequently isolated, this condition has been reported to be associated with other congenital anomalies, genetic disorders, and various urogenital anomalies more than 50% of the time. However, we found no cases linking CFRE with a solitary testicle. This is a case of a 30-year-old man with left-to-right CFRE with concomitant absent left testicle and obstructing distal calculus.

Fine needle aspiration biopsy of primary renal synovial sarcoma. A case report.

BACKGROUND: Primary renal synovial sarcoma is a relatively recently described and characterized neoplasm, formerly designated embryonal sarcoma of the kidney, and has not been diagnosed before by fine needle aspiration biopsy cytology. We describe the cytologic features of a malignant biphasic neoplasm of the kidney that was subsequently diagnosed at nephrectomy and confirmed with molecular genetic analysis as a biphasic renal synovial sarcoma. CASE: A 38-year-old male presented with acute abdominal pain. Computed tomography (CT) demonstrated a 4.7-cm mass in the left kidney. No soft tissue or extrarenal masses were identified. A CT-guided fine needle aspiration biopsy revealed a malignant biphasic tumor characterized by minimally atypical tubular epithelium, immature spindle cells and foci of coagulative tumor necrosis. At nephrectomy, a necrotic, pseudo-encapsulated synovial sarcoma of the upper pole of the left kidney was identified and was additionally evaluated with immunohistochemistry and molecular genetic studies. The case is unique since biphasic synovial sarcomas have yet to be reported to occur in the kidney and fine needle aspiration biopsy findings of this renal neoplasm have never been reported to our knowledge. CONCLUSION: Synovial sarcoma should be a diagnostic consideration particularly in a young adult with a malignant spindle cell neoplasm of the kidney. The list of differential diagnoses should include sarcomatoid renal cell carcinoma, sarcomatoid transitional cell carcinoma of the renal pelvis, angiomyolipoma and monophasic or biphasic synovial sarcoma.