Imaging characterization and differential diagnosis of primary renal malignant fibrous histiocytoma / 实用放射学杂志

ABSTRACT

Objective To investigate CT and MRI findings of primary malignant fibrous histiocytoma (MFH)in the kidney. Methods The clinical data and imaging findings of 7 patients with primary renal MFH proved by histopathology were reviewed retrospectively.Results Tumors were unilateral in all patients,in which 5 cases were in the left kidney and 2 cases in the right kidney.The maximum diameter of the lesions ranged from 3.5 to 17.1 cm,with a mean of (8.7±3.9)cm.All the masses showed shallow lobulated or oval, with obscure boundary.On CT plain scan,heterogeneous isodensity/hypodensity were showed in 7 cases,necrosis occured in 7 cases, intratumoral hemorrhage in 2 cases and calcification in 3 cases.MRI also showed heterogeneous signal intensity.No obvious pseudocapsule was found in 6 cases.On dynamic contrast enhancement scan mild-moderate progressive enhancement was showed in corticomedullary and parenchymal phase in all 7 cases.In delay phase slightly decreased enhancement were showed in 5 cases,and similar or slightly higher enhancement corresponding to the parenchymal phase was showed in 2 cases.However,lower enhancement was showed in the tumors on all 3 phases than that in the renal cortex.Besides,the tumors invaded the renal vein (n=1)and the adjacent structure (n=3).Conclusion No specific imaging findings of primary renal MFH are found.The dynamic contrast enhancement might be helpful for its diagnosis to some extent,and clinical data should be integrated with imaging findings together to differentiate renal MFH from other renal neoplasms.The final diagnosis relies on pathology and immunohistochemistry examination.