Diagnostic accuracy of pre-operative imaging findings in presumed clinical T1a renal cell carcinomas

Abstract

Abstract. Despite the development of recent imaging modalities, certain pathological misdiagnoses remain for surgical specimens of presumed small renal cell carcinomas (RCCs). In the present study, a retrospective analysis of benign pathological lesions diagnosed as small RCC prior to surgery was performed. In total, the cases of 196 sporadic renal tumors that was surgically treated as clinical T1a RCCs were reviewed, and the accuracy of the pathological diagnoses was calculated. The pre-operative findings for benign pathological lesions was investigated, and the lesions were observed in 13 (6.63%) of the 196 tumors. Pre-operative computed tomography images were obtained in all cases, and magnetic resonance images were available in 10 cases. The diagnostic accuracy of imaging modalities was significantly lower in the tumors with a diameter of ≤20 mm. In all cases, the possible pathological diagnosis of RCC could not be excluded even by retrospective imaging analysis. Several benign pathological lesions were found in small renal masses presumed to be clinical T1a RCC. In conclusion, there may be limitations to the pre-operative imaging for certain types of small renal mass.

Correlation between radiological and histopathological findings in patients undergoing nephrectomy for presumed renal cell carcinoma on computed tomography scan at Grey’s Hospital

“…This is contradicted by what is described in the literature where CT has been well documented to have high sensitivity and specificity. 1,2,8 We believe that this is partly explained by the low number of patients with extra-renal extension and venous invasion in the study. Further scrutiny, however, may support the concept that CT diagnosis of extra-renal and vascular invasion in RCC is difficult.…”

“…It has a diagnostic accuracy of up to 93% and sensitivity and specificity for staging of up to 90%. 1,2,8…”

“…12 Nakashima et al attributed a low benign incidence rate of 6.63% in their study to the use of magnetic resonance imaging (MRI) in conjunction with CT scan in their patients, as MRI is known to be more sensitive in detecting small amounts of intralesional fat. 8…”

“…Some studies have reported lipid-poor angiomyolipoma to be the most common benign tumour presumed to be RCC on CT scan, followed by oncocytoma. 8,9,10,11,16 Ethnicity may predict the type of benign tumours found at nephrectomy performed for presumed RCC, with most Asian studies reporting angiomyolipoma as the most common benign tumour and studies from the US reporting oncocytoma. 2,8,10,11,12 Oncocytoma cannot be confidently distinguished from RCC on imaging.…”

Visual evaluation and differentiation of renal oncocytomas from renal cell carcinomas by means of 99mTc-sestamibi SPECT/CT

“…Those diagnostic features are not only unspecific but also directly dependent on the imaging quality of the examination scan [17]. In addition, the diagnostic accuracy of the aforementioned imaging modalities tends to be significantly lower in tumours with a diameter of ≤20 mm [23]. …”