Purpose
A peritumoral pseudocapsule, composed of fibrous connective tissue and compressed adjacent renal parenchyma, is frequently observed in renal cell carcinoma (RCC) pathologically [1]. Compared to MRI, CT is less sensitive in detecting pseudocapsules [2,3]. Some reports define a high-attenuation rim in the contrast-enhanced CT images including the early phase as a sign of a pseudocapsule [4,5]. The findings of a pseudocapsule on CT are confusing as fibrous tissue must not be enhanced in the early phase images, and have room for improvement.
We found that...
Methods and materials
Patients
This retrospective single-institution study was approved by the institutional review board of our facility. Written informed consent for the use of individual patient data in the analysis was waived because of the retrospective nature of the investigation. A total of 281partial nephrectomies were performed for renal tumors between January 2017 and February 2018. Of these, 75 patients were excluded for no preoperative contrast-enhanced CT at our institution (n = 61), rare neoplasms (n = 4), non-neoplastic lesions (n = 7), and AML with apparent...
Results
In total, the EDCB was observed in 110 of 206 (53.4%) renal tumors. The rates of detection of the EDCB in ccRCC, chromophobe RCC (chRCC), papillary RCC (pRCC), clear cell papillary RCC (ccpRCC), Fp-AML, and oncocytoma, were 66.0% (103 of 156), 18.8% (3 of 16), 0% (0 of 12 ), 50.0% (3 of 6), 0% (0 of 12), and 50.0% (2 of 4), respectively (Figure 2–4). The EDCB was observed in hypervascular tumors, mainly in ccRCC. There was a substantial interobserver agreement for the presence...
Conclusion
The EDCB sign, which is an unenhanced thin line at the tumor-renal cortex border in the corticomedullary phase CT images, was observed in nearly two-thirds of ccRCCs treated by partial nephrectomy. Although the EDCB could reflect pathological pseudocapsule of ccRCC, diagnostic accuracy was inadequate. The EDCB sign can be one of the predictors for differentiating ccRCC from Fp-AML, as it was not observed in Fp-AML.
The discussion points and limitations are as follows:
Detection of the EDCB depends on the tumor vascularity based on the...
Personal information and conflict of interest
Y. Ogawa:
Investigator: main investigator
S. Morita:
Investigator: main investigator
T. Takagi:
Investigator: co-investigator
K. Yoshida:
Investigator: co-investigator
K. Tanabe:
Investigator: co-investigator
Y. Nagashima:
Investigator: co-investigator
Y. Nishina:
Investigator: co-investigator
S. Sakai:
Investigator: co-investigator
References
Yamashita Y, Takahashi M, Watanabe O, et al (1992) Small renal cell carcinoma: pathologic and radiologic correlation. Radiology 184:493-498
Yamashita Y, Honda S, Nishiharu T, et al (1996) Detection of pseudocapsule of renal cell carcinoma with MR imaging and CT. AJR 166:1151-1155
Tsili AC, Argyropoulou MI, Gousia A, et al (2012) Renal cell carcinoma: value of multiphase MDCT with multiplanar reformations in the detection of pseudocapsule. AJR 199:379-386
Ma Y, Cao F, Xu X, et al (2020) Can whole-tumor radiomics-based CT analysis better differentiate fat-poor...