Case Report: A Case of Renal Cell Carcinoma Unclassified With Multi-organ Invasion

Background: Most unclassified renal cell carcinoma (RCC) pressent with high-grade histologic features or distant metastasis and are reported to have lower survival rates. We present a rare case of multi-organ invasion from unclassified RCC with good prognosis, to increase knowledge of the characteristics for unclassified RCC. Case Presentation A 66-year-old female presented with an incidentally detected left renal mass on a health examination. The patient had no obvious symptoms and had past medical history of hypertension. CT scans show a mixed tissue density mass located at the higher pole of the left kidney, with a range of 89*68 mm. The tumor boundary was not clear based on imaging findings, which may invading the retroperitoneum, spleen and part of the pancreas. Therefore a multiorgan resection, including left kidney, spleen, pancreatic body and tail, was performed. The final pathology confirmed unclassified renal cell carcinoma which involved the left adrenal gland and pancreas. Sunitinib and penpulimab were administered to the patient and follow-up date showed no symptom of further progression. Conclusion: Unclassified RCC is a rare malignant tumor with poor prognosis and the definite diagnosis relies on the pathology. For patients with advanced unclassified RCC, multiple organ resection is worthwhile with careful patient selection.