Renal Leiomyosarcoma With Regional Lymph Node Metastasis and Biopsy Tract Seeding: A Case Report.

Renal leiomyosarcoma is a rare and aggressive tumor that comprises a very small proportion of adult kidney malignancies. Its clinical and imaging characteristics can closely resemble those of other high-grade renal tumors, which complicates the diagnostic process. We report the case of a 66-year-old male patient who presented with a large left renal mass and was diagnosed with high-grade pleomorphic leiomyosarcoma. He underwent radical nephrectomy along with en bloc removal of a para-aortic lymph node, which was histologically confirmed to contain metastatic disease. In an unusual postoperative development, the patient presented with a subcutaneous mass at the prior biopsy site. This was confirmed to be tumor seeding along the biopsy tract, an infrequent occurrence in renal sarcomas.