Renal pseudotumors- characterization with contrast-enhanced ultrasound (CEUS)

A. Lewicki; M. Jędrzejczyk; W. Jakubowski; W. Pypno; P. Marczyñski; A. Lewicka

doi:10.1055/s-2008-1079983

Ultraschall in der Medizin - European Journal of Ultrasound, Inhaltsverzeichnis

Renal pseudotumors- characterization with contrast-enhanced ultrasound (CEUS)

A Lewicki ¹, M Jędrzejczyk ², W Jakubowski ², W Pypno ³, P Marczyñski ¹, A Lewicka ⁴

¹Urology Department, Memorial Lord's Transfiguration Hospital, Warsaw, Poland; Urology Department, Postgraduate Medical Academy, Warsaw, Poland
²Department of Diagnostic Imaging, Second Faculty of Medicine, Medical University of Warsaw, Poland
³Urology Department, Postgraduate Medical Academy, Warsaw, Poland
⁴Department and Clinic of Obstetrics, Gynecology and Oncology, Medical University of Warsaw, Poland

Abstract

The work is supported by scientific grant from the ministry of science and higher education no 2po5b05330.

Renal pseudotumors are non-neoplastic lesions which can mimic renal malignancy in imaging methods. They often reqiure further investigations after grey scale ultrasound (GS-US) in order to confidently exclude expansive masses.

Aims: To assess the value of CEUS in differential diagnosiss of renal pseudotumors. To assess pseudotumors' frequency occurence among lesions directed to more sophisticated examinations after GS-US.

Materials and methods: 125 patients with 131 renal masses directed to further investigations after GS-US were examined. CEUS was performed with Voluson 730 Expert, probe C2–5MHz/3D C2–5MHz. The kidneys were examined three times: GS-US with Doppler examination, Coded Pulse Inversion option after bolus injection of ultrasound contrast agent (UCA) and Coded Harmonic Angio option after second dose of UCA. As a UCA 1.2ml SonoVue was used. Vascularization (its regularity, modelling features) and enhancement character of the lesion and normal parenchyma were evaluated. Reference examinations were contrast-enhanced computed tomography (CECT) and histopathologic outcomes of resected lesions.

Results: Among 131 focal lesions suspected on grey scale US, 29 (22.1%) CEUS verified as renal pseudotumors. They were: hyperthrophic column of Bertin 7 (24.1%), focal parenchyma hyperthrophy 4 (13.8%), junctional parenchyma defect 2 (6.9%), renal hump 2 (6.9%), hypoechoic renal sinus fat 1 (3.4%), infectious lesions (scarred kidney, areas of fibrosis) 4 (13.8%), abscess 1 (3.4%), hematoma 1 (3.4%), cystic pseudotumors (cysts I, II according to Bosniak classification system) 5 (17.2%), pseudotumor after nephron-sparing surgery 1 (3.4%). Differences in evaluation with CECT were found in 3 lesions (10.3% of pseudtumors):

CEUS: cyst cat. II; CECT: solid mass; histopathologic result: cyst without malignancy
CEUS: tumor in the renal hilum; CECT: area of parahiliar fatty tissue; Patient didn't announce for planned follow up,
CEUS: necrotic area (organized hematoma); CECT: tumor suspected for malignancy; histopathologic result: necrosis without neoplastic cells.

Compliance with histopathologic results of resected lesions (3) was: CECT 1/3, CEUS 3/3.

Conclusions:

CEUS is an efficiacious method in the diagnosis of renal pseudotumors with diagnostic precision similar to CECT.
Above 22% of lesions suspected for renal malignancy on GS-US in refrence examinations revealed to be pseudotumors.