Atypical presentation of renal cell carcinoma with lactic acidosis: case report and literature review.

Renal cell carcinoma is often difficult to diagnose early due to its nonspecific clinical presentation, which extends beyond the classic triad of flank pain, hematuria, and a flank mass. Recognizing alternative indicators, such as microscopic hematuria and lactic acidosis, can aid in early detection. A 77-year-old male with diabetes, varicose veins, and tobacco use presented with weakness, nausea, dyspnea, and poor appetite. He exhibited somnolence, confusion, transaminitis, elevated alkaline phosphatase, and severe lactic acidosis. Urinalysis revealed microscopic hematuria. Imaging showed bilateral pleural effusions and a right hepatic lesion. A computed tomography scan identified a large renal mass invading the renal vein, inferior vena cava, and right atrium. The patient developed deep vein thromboses and underwent radical nephrectomy, but succumbed postoperatively. This case highlights renal cell carcinoma's potential for atypical presentations, emphasizing the importance of early recognition and comprehensive diagnostic approaches to improve outcomes.