Scientific Publications Database

Article Title: Are growth patterns on MRI in small (< 4 cm) solid renal masses useful for predicting benign histology?
Authors: Lim, Robert S.; McInnes, Matthew D. F.; Siddaiah, Mahadevaswamy; Flood, Trevor A.; Lavallee, Luke T.; Schieda, Nicola
Journal: EUROPEAN RADIOLOGY Volume 28 Issue 8
Date of Publication:2018
Abstract:
To evaluate previously described growth patterns in < 4 cm solid renal masses.With IRB approval, 63 renal cell carcinomas (RCC; clear cell n = 22, papillary n = 28, chromophobe n = 13) and 36 benign masses [minimal-fat (mf) angiomyolipoma (AML) n = 13, oncocytoma n = 23) from a single institution were independently evaluated by two blinded radiologists (R1/R2) using T2-weighted MRI for (1) the angular interface sign (AIS), (2) bubble-over sign (BOS), (3) percentage (%) exophytic growth and (4) long-to-short axis ratio. Comparisons were performed using ANOVA, chi-square and multi-variate regression.AIS was present in 11.1% (7/63) -9.5% (6/63) R1/R2 RCC compared to 13.9% (5/36) -19.4% (7/36) R1/R2 benign masses (p = 0.68 and 0.16). BOS was present in 11.1% (7/63) -3.2% (2/63) R1/R2 RCC compared to 16.7% (6/36) -8.3% (3/36) R1/R2 benign masses (p = 0.432 and 0.261). Agreement was moderate (K = 0.50 and 0.55). mf-AML [66 +/- 32% (range 0-100%)] and oncocytoma [53 +/- 26% (0-90%)] had larger % exophytic growth compared to RCC [32 +/- 23% (0-80%)] (p < 0.001). No RCC had 90-100% exophytic growth, present in 38.5% (5/13) mf-AMLs and 17.4% (4/23) oncocytomas. The long-to-short axis did not differ between groups (p = 0.053).Benign masses show greater % exophytic growth whereas other growth patterns are not useful. Future studies evaluating % exophytic growth using multi-variate MR analysis in renal masses are required.aEuro cent Greater exophytic growth is associated with benignity among solid renal masses.aEuro cent Only minimal fat AMLs and oncocytomas had 90-100% exophytic growth.aEuro cent The angular interface sign was not useful to differentiate benign masses from RCC.aEuro cent The bubble-over sign was not useful to differentiate benign masses from RCC.aEuro cent Subjective analysis of growth patterns had fair-to-moderate agreement.