[Pathological correlation of dynamic magnetic resonance findings for chromophobe cell renal carcinoma]

To explore the dynamic magnetic resonance (MR) imaging findings of chromophobe cell renal carcinoma and evaluate its pathological correlation.

Twelve cases with chromophobe cell renal carcinoma confirmed by surgical pathology underwent MR plain scanning and dynamic enhancement scanning before operation. And the MR data were reviewed and analyzed retrospectively in comparison with surgical and pathological results.

Twelve lesions were located in right kidney (n = 9) and left kidney (n = 3) with a mean tumor diameter of 7.3 cm (range: 3.2 - 12.6 cm). They were located in renal cortex (n = 1), renal medulla (n = 9) and the middle of cortex and medulla with a relatively normal renal shape. Nine lesions appeared global and 3 elliptic in shape. Well-defined margin was showed in 12 lesions and a thin capsule was observed in all lesions. The tumor presented a low to middle homogeneous signal intensity on T1WI and intermediates homogeneous signal intensity on fat saturated FSE-T2WI with a hypointense thin capsule and a hyperintense central scar. A mild-to-middle degree of tumor enhancement in cortical phase (tumor SI change 120.3% with a standard deviation of 84.3 and a median of 115.2%) was slightly lower, isointense or slightly higher than renal medulla. And obvious enhancement in portal venous phase(tumor SI change 173.7% with a standard deviation of 92.4 and a median of 171.5%) was lower than renal medulla.

Chromophobe cell renal carcinoma typically forms large and well-circumscribed global solid masses in renal medulla. With a relatively normal renal shape and a thin capsule, it shows intermediate homogeneous signal intensity on T1WI and T2WI. And a middle degree enhancement with central stellate scar is found in some patients.