Isolated Scar Site and Renal Bed Recurrence of Renal Cell Carcinoma: A Rare Case Report

Renal cell carcinoma (RCC) is known for its unpredictable metastatic patterns, often presenting challenges in management. Understanding the unique recurrence patterns is crucial for improving patient outcomes. The authors report a case of a 56-year male with a history of carcinoid tumour treated by left pneumonectomy in 2015 and was found to have a large solid renal mass on screening CT. He underwent an open radical nephrectomy. He experienced an isolated renal scar site metastasis and renal fossa recurrence one year post-surgery. The metastasis presented as a painful 7 × 8 cm swelling at the surgical incision site. Imaging and biopsy confirmed metastatic RCC at both sites. He underwent local excision of the scar site metastasis and renal fossa recurrence. Although the abdominal wall mass was excised completely, dense vascular adhesions prevented the complete resection of the renal fossa mass. Histopathology confirmed metastatic RCC, with postoperative imaging revealing a residual tumour in the renal bed. Systemic therapy was recommended, and follow-up imaging every three months showed stable disease. This report highlights the rarity of simultaneously isolated recurrences at these sites and discusses the implications for surgical and systemic management, including the role of vigilant follow-up and consideration of emerging systemic therapies.