A rare case of bilateral synchronous renal cancer, characterized by distinct histologies; leiomyosarcoma and clear cell renal cancer

INTRODUCTION: Renal cancer is a significant global cause of death and clear cell being the most common subtype. Bilateral synchronous renal cancers with different histologies are extremely rare and less reported. Managing bilateral renal cancer is challenging. CLINICAL PRESENTATION: A 51-year-old woman with a history of hypertension and hypothyroidism presented with right loin pain, leading to the discovery of a 7 cm right renal mass and a 2.3 × 2.6 cm mass on the upper pole of the left kidney, associated with reactive right para-aortic lymph nodes. The right kidney mass was identified as leiomyosarcoma with liver metastasis while the left kidney mass was diagnosed as clear cell renal carcinoma. Patient was managed with right side nephrectomy, left side microwave ablation and follow-up chemotherapy. DISCUSSION: Primary leiomyosarcoma of kidney is extremely rare and aggressive, leading to poor outcome. Synchronous bilateral renal cancer pose surgical challenges due to potential loss of renal function. In this case of differing histologies in synchronous bilateral renal masses, a nephron-sparing approach was taken, but despite aggressive treatment, the patient developed metastases in the liver and peritoneum. CONCLUSION: Bilateral synchronous renal cancer, particularly with differing histologies in each kidney, are exceptionally uncommon, making their management challenging. Despite the limited guidance available due to their rarity, addressing these cases aggressively and promptly is crucial, as their prognosis is generally unfavorable, necessitating further research to advance management strategies.