Renal collision tumours: three additional case reports.

BACKGROUND: Multiple kidney tumours are frequently seen in hereditary syndromes and familial diseases. Renal collision tumours (RCT) are characterized by the simultaneous existence of different and unrelated tumour types within the same location in the kidney, forming a single, heterogenous lesion. RCT are uncommon histological entities with distinctive features. The most frequent subtypes include clear cell renal cell carcinoma (CCRCC), papillary renal cell carcinoma (PRCC), chromophobe renal cell carcinoma (CRCC), and collecting duct carcinoma (CDC). CASE PRESENTATION: Here, we report three sporadic cases of RCT successfully treated by nephrectomy and confirmed by histological analysis. The first case was of a 64-year-old man diagnosed with RCT composed of a stage 2 nucleolar grade 3 CCRCC and a stage 1a nucleolar grade 2 type 1 PRCC. The second case was of a 68-year-old woman diagnosed with a combined nucleolar grade 2 type 1 PRCC and an angiomyolipoma (non-assessed stage), while the third case was of a 59-year-old woman diagnosed with a combined stage 1a nucleolar grade 3 CCRCC and a stage 1b CDC. CONCLUSIONS: Due to the rarity of RCT, there are no standard guidelines for their management. Hence, the prognosis is considered to be associated with the most aggressive component, possibly the tumour with the highest nucleolar grade and stage. The histogenesis of RCT remains debated, and increase in knowledge regarding this can help enable the development of targeted therapies for advanced or metastatic tumours.

99mTc-mebrofenin hepatobiliary scintigraphy and volume metrics before liver preparation: correlations and discrepancies in non-cirrhotic patients.

BACKGROUND: Accurate identification of insufficient future liver remnant (FLR) is required to select patients for liver preparation and limit the risk of post-hepatectomy liver failure (PHLF). The objective of this study was to investigate the correlations and discrepancies between the most-commonly used FLR volume metrics and 99mTc-mebrofenin hepatobiliary scintigraphy (HBS). METHODS: In 101 non-cirrhotic patients who underwent HBS before major hepatectomy, we retrospectively analyzed the correlations and discrepancies between FLR function and FLR volume metrics: actual percentage (FLRV%), standardized to body surface area (FLRV%BSA) and weight (FLRV%weight), and FLR to body weight ratio (FLRV-BWR). RESULTS: Among 67 patients with FLR function ≥2.69%/min/m2, PHLF was observed in none and 13 patients according to respectively 50-50 and ISGLS criteria. FLRV%, FLRV%BSA, FLRV%weight and FLRV-BWR significantly correlated with FLR function (P<0.001), with Spearman's correlation coefficients of 0.680, 0.704, 0.698, and 0.711, respectively. No difference was observed between the areas under the curve of FLRV%, FLRV%BSA, FLRV%weight and FLR-BWR (all P=ns). Overall, the percentages of patients misclassified by FLRV%, FLRV%BSA, FLRV%weight (thresholds: 30%) and FLR-BWR (threshold: 0.5) versus FLR function (threshold: 2.69%/min/m2) were 23.8% (95% CI: 15.9-33.3%), 18.8% (95% CI: 11.7-27.8%), 17.8% (95% CI: 11-26.7%), and 31.7% (95% CI: 22.8-41.7%), respectively. FLR volume metrics wrongly classified 1-13.9% of patients with sufficient FLR function (i.e., ≥2.69%/min/m2), and 9.9-30.7% of patients with insufficient FLR function. FLRV-BWR was the most and the least reliable measure to identify patients with sufficient and insufficient FLR function, respectively. CONCLUSIONS: Despite significant correlations, the discrepancy rates between FLR volume and function metrics speaks in favor of implementing 99mTc-mebrofenin HBS in the work-up before liver preparation.