Tumor Necrosis on Magnetic Resonance Imaging Correlates With Aggressive Histology and Disease Progression in Clear Cell Renal Cell Carcinoma

Abstract

Purpose To correlate the magnetic resonance imaging (MRI) features of clear cell renal cell carcinoma (ccRCC) with the histopathological features and disease progression. Material and Methods IRB approval for this retrospective study was obtained; patient consent was not required. The initial staging MRIs of 75 patients with histologically confirmed ccRCC were retrospectively reviewed. The imaging was assessed by two radiologists for the presence of tumor necrosis, cystic degeneration, intracellular fat, hemorrhage, retroperitoneal collaterals and renal vein thrombosis. Quantitative analysis for the MRI presence of intracellular lipid within tumors was performed. MRI findings were correlated with histopathologic findings of clear cell percentage, alveolar and tubular growth pattern and disease progression. Statistical associations were evaluated with non-parametric univariable analyses and multivariable logistic regression models. Results Correlation between MRI and histopathologic features was performed in 75 patients whereas follow-up data was available for progression analysis in 68 patients. The presence of tumor necrosis, retroperitoneal collaterals and renal vein thrombosis on MRI were significantly associated with low percentage of tumor cells with clear cytoplasm (p<0.01) and with metastatic disease at presentation or disease progression (p<0.01). At multivariable analysis, necrosis remained as the only feature statistically associated with disease progression (p=0.03, adjusted odds ratio=27.7, CI 95%=1.4–554.7 for reader one and p=0.02, adjusted odds ratio=29.3, CI 95%=1.7–520.8 for reader two). Conclusion Necrosis in ccRCC on MRI correlates with the histopathological finding of lower percentage of tumor cells with clear cytoplasm and is a poor prognostic indicator irrespective of tumor size.

Clear Cell Renal Cell Carcinoma: Associations Between CT Features and Patient Survival

“…This finding expands on the results of prior studies. For example, an association between the presence of necrosis on imaging and increased tumor aggressiveness (i.e., a higher Fuhrman grade for ccRCC) has previously been reported [14, 15]. To our knowledge, the first evidence supporting our hypothesis was published by Raj et al [13], who incorporated the presence of necrosis on imaging into a preoperative nomogram.…”

Ten uncommon and unusual variants of renal angiomyolipoma (AML): radiologic–pathologic correlation

“…AMLs are the second leading cause of non-traumatic renal haemorrhage after RCCs. 33 Because haemorrhage often obscures the underlying mass, including areas of intra-lesion fat, the cause of AML-related haemorrhage can be mistaken as being related to an RCC or other causes of haemorrhage. 34 Furthermore, when haemorrhage extends into the retroperitoneal fat it may simulate the presence of a mass that contains intralesional fat and lead to the erroneous diagnosis of AML (Figs 7 and 8).…”

MRI Phenotype in Renal Cancer

“…In addition, necrosis has been shown to be a significant marker of adverse prognosis, even independent of histologic grade, determined by both histopathologic analysis 69 and MRI. 70 Retro peritoneal vascular collaterals and renal vein thrombosis (Fig. 4) have also both been associated with high-grade clear cell RCC.…”