Giant Papillary Renal Cell Carcinoma: A Rare Case of a 31-cm Renal Mass With Suspected Metastatic Disease on Imaging

Papillary renal cell carcinoma (pRCC) is a recognized subtype of renal cell carcinoma (RCC) with variable clinical and radiologic presentations.Exceptionally large tumors with metastatic involvement represent an unusual presentation.We report a case of a massive pRCC with metastatic disease, highlighting its aggressive clinical and radiologic features.A 50-year-old male presented with a right flank mass and abdominal pain persisting for several months.He had no history of smoking or known genetic syndromes.Laboratory investigations showed mild anemia and microscopic hematuria, while renal and liver function tests were within normal limits.Imaging studies, including computed tomography and magnetic resonance imaging, revealed a large centrally necrotic right renal mass measuring 24×19×31 cm, with associated lung and bone findings, concerning for metastases.A renal biopsy confirmed the diagnosis of papillary renal cell carcinoma.This case highlights an atypical presentation of pRCC, with an exceptionally large tumor size, T2 hyperintensity, central necrosis, and radiologically suspected metastatic disease at the time of diagnosis.While pRCC is generally smaller, weakly enhancing, T2 hypointense, and less aggressive than clear cell RCC, this case demonstrates that exceptionally large renal masses may have atypical imaging appearances.Therefore, pRCC should remain within the differential diagnosis, and histopathological confirmation is required for definitive diagnosis.Management of metastatic pRCC should be individualized based on disease burden, resectability, patient factors, and available systemic treatment options.Further research is warranted to better understand the biological mechanisms underlying aggressive tumor behavior.This report aimed to highlight a rare case, emphasizing its clinical significance due to its unusual presentation, notable mass effect, complexities in differential diagnosis, and radiologically suspected metastatic involvement.Specifically, we describe a case involving a sizable, necrotic, and contrast-enhanced pRCC that deviates from the conventional clinical and radiological features commonly associated with this tumor subtype.