Small renal masses
- Hersh Chandarana1
© Chandarana 2015
Published: 2 October 2015
Small renal masses are increasingly diagnosed incidentally. This results in management dilemma because at histopathology significant numbers of small renal masses are either benign tumors such as angiomyolipoma (AML) or oncocytoma, or are neoplasms with relatively indolent behavior . Surgical treatments such as partial and total nephrectomy although provide excellent oncologic control is associated with development and worsening of renal insufficiency and associated cardiovascular morbidity . Therefore, ability to non-invasively investigate renal tumor histopathology and aggressiveness can guide treatment decision and lower treatment cost.
Within this paradigm, the role of radiologist and imaging is evolving from traditional role of identifying renal lesion and detecting enhancement, to predicting aggressiveness and biology of the tumor as well as providing operative guidance. MR imaging can play a very important role not only as a problem solving tool in traditional sense by detecting subtle enhancement and macroscopic and microscopic fat, but can provide deeper insight into tumor biology. Number of key observations highlighting the role of MR in evaluation of renal masses is as listed below:
1. Differentiating benign renal masses from malignant tumors
- There is overlap in the morphologic features of Oncocytoma and RCC on conventional imaging . Furthermore segmental enhancement inversion is noted in oncocytoma as well as other renal neoplasms .
2. Histologic subtyping RCC
- Papillary subtype of RCC usually have low T2 signal and are hypovascular when compared to clear cell RCC. Furthermore, clear cell subtype have heterogeneous T2 signal and demonstrate heterogeneous hypervascularity .
- Chromophobe subtype is difficult to differentiate from clear cell RCC on the basis of enhancement. However, advance diffusion and perfusion MR techniques have shown some promise .
3. Predicting tumor aggressiveness/outcome
- Cystic RCC with less than 25% solid enhancing component tend to be less aggressive than solid RCC .
- High stage clear cell RCC tend to me more heterogeneous with different texture compared to low stage RCC on Apparent diffusion coefficient (ADC) map .
- High grade clear cell RCC tend to have lower ADC compared to low grade clear cell RCC .
- Thompson RH, Kurta JM, Kaag M, et al: Tumor size is associated with malignant potential in renal cell carcinoma. J Urol. 2009, 181 (5): 2033-6. 10.1016/j.juro.2009.01.027.PubMedPubMed CentralView ArticleGoogle Scholar
- Huang WC, Levey AS, Serio AM, et al: Chronic kidney disease after nephrectomy in patients with renal cortical tumours: A retrospective cohort study. The Lancet. Oncology. 2006, 7: 735-740. 10.1016/S1470-2045(06)70803-8.PubMedPubMed CentralView ArticleGoogle Scholar
- Kim JK, Kim SH, Jang YJ, et al: Renal angiomyolipoma with minimal fat: differentiation from other neoplasms at double-echo chemical shift FLASH MR imaging. Radiology. 2006, 239 (1): 174-80. 10.1148/radiol.2391050102.PubMedView ArticleGoogle Scholar
- Jhaveri KS, Elmi A, Hosseini-Nik H, et al: Predictive Value of Chemical-Shift MRI in Distinguishing Clear Cell Renal Cell Carcinoma From Non-Clear Cell Renal Cell Carcinoma and Minimal-Fat Angiomyolipoma.Google Scholar
- Hindman N, Ngo L, Genega EM, et al: Angiomyolipoma with minimal fat: can it be differentiated from clear cell renal cell carcinoma by using standard MR techniques?. Radiology. 2012, 265 (2): 468-77. 10.1148/radiol.12112087.PubMedPubMed CentralView ArticleGoogle Scholar
- Sasiwimonphan K, Takahashi N, Leibovich BC, Carter RE, Atwell TD, Kawashima A: Small (<4 cm) renal mass: differentiation of angiomyolipoma without visible fat from renal cell carcinoma utilizing MR imaging. Radiology. 2012, 263 (1): 160-8. 10.1148/radiol.12111205.PubMedView ArticleGoogle Scholar
- Rosenkrantz AB, Hindman N, Fitzgerald EF, Niver BE, Melamed J, Babb JS: MRI features of renal oncocytoma and chromophobe renal cell carcinoma. AJR Am J Roentgenol. 2010, 195 (6): W421-7. 10.2214/AJR.10.4718.PubMedView ArticleGoogle Scholar
- Schieda N, Al-Subhi M, Flood TA, El-Khodary M, McInnes MD: Diagnostic accuracy of segmental enhancement inversion for the diagnosis of renal oncocytoma using biphasic computed tomography (CT) and multiphase contrast-enhanced magnetic resonance imaging (MRI). Eur Radiol. 2014, 24 (11): 2787-94. 10.1007/s00330-014-3310-y.PubMedView ArticleGoogle Scholar
- Chandarana H, Rosenkrantz AB, Mussi TC, et al: Histogram analysis of whole-lesion enhancement in differentiating clear cell from papillary subtype of renal cell cancer. Radiology. 2012, 265 (3): 790-8. 10.1148/radiol.12111281.PubMedView ArticleGoogle Scholar
- Chandarana H, Amarosa A, Huang WC, et al: High temporal resolution 3D gadolinium-enhanced dynamic MR imaging of renal tumors with pharmacokinetic modeling: preliminary observations. J Magn Reson Imaging. 2013, 38 (4): 802-8. 10.1002/jmri.24035.PubMedView ArticleGoogle Scholar
- Doshi AM, Huang WC, Donin NM, Chandarana H: MRI features of renal cell carcinoma that predict favorable clinicopathologic outcomes. AJR Am J Roentgenol. 2015, 204 (4): 798-803. 10.2214/AJR.14.13227.PubMedView ArticleGoogle Scholar
- Kierans AS, Rusinek H, Lee A, et al: Textural differences in apparent diffusion coefficient between low- and high-stage clear cell renal cell carcinoma. AJR Am J Roentgenol. 2014, 203 (6): W637-44. 10.2214/AJR.14.12570.PubMedView ArticleGoogle Scholar
- Rosenkrantz AB, Niver BE, Fitzgerald EF, Babb JS, Chandarana H, Melamed J: Utility of the apparent diffusion coefficient for distinguishing clear cell renal cell carcinoma of low and high nuclear grade. AJR Am J Roentgenol. 2010, 195 (5): W344-51. 10.2214/AJR.10.4688.PubMedView ArticleGoogle Scholar
This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.