Association between nuclear grade of renal cell carcinoma and the aorta-lesion-attenuation-difference.

INTRODUCTION AND BACKGROUND: Several features noted on renal mass biopsy (RMB) can influence treatment selection including tumor histology and nuclear grade. However, there is poor concordance between renal cell carcinoma (RCC) nuclear grade on RMB compared to nephrectomy specimens. Here, we evaluate the association of nuclear grade with aorta-lesion-attenuation-difference (ALAD) values determined on preoperative CT scan. METHODS AND MATERIALS: A retrospective review of preoperative CT scans and surgical pathology was performed on patients undergoing nephrectomy for solid renal masses. ALAD was calculated by measuring the difference in Hounsfield units (HU) between the aorta and the lesion of interest on the same image slice on preoperative CT scan. The discriminative ability of ALAD to differentiate low-grade (nuclear grade 1 and 2) and high-grade (nuclear grade 3 and 4) tumors was evaluated by sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and area under curve (AUC) using ROC analysis. Sub-group analysis by histologic sub-type was also performed. RESULTS: A total of 368 preoperative CT scans in patients with RCC on nephrectomy specimen were reviewed. Median patient age was 61 years (IQR 52-68). The majority of patients were male, 66% (243/368). Tumor histology was chromophobe RCC in 7.6%, papillary RCC in 15.5%, and clear cell RCC in 76.9%. The majority, 69.3% (253/365) of tumors, were stage T1a. Nuclear grade was grade 1 in 5.46% (19/348), grade 2 in 64.7% (225/348), grade 3 in 26.2% (91/348), and grade 4 in 3.2% (11/348). Nephrographic ALAD values for grade 1, 2, 3, and 4 were 73.7, 46.5, 36.4, and 43.1, respectively (p = 0.0043). Nephrographic ALAD was able to differentiate low-grade from high-grade RCC with a sensitivity of 32%, specificity of 89%, PPV of 86%, and NPV of 36%. ROC analysis demonstrated the predictive utility of nephrographic ALAD to predict high- versus low-grade RCC with an AUC of 0.60 (95% CI 0.51-0.69). CONCLUSION: ALAD was significantly associated with nuclear grade in our nephrectomy series. Strong specificity and PPV for the nephrographic phrase demonstrate a potential role for ALAD in the pre-operative setting that may augment RMB findings in assessing nuclear grade of RCC. Although this association was statistically significant, the clinical utility is limited at this time given the results of the statistical analysis (relatively poor ROC analysis). Sub-group analysis by histologic subtype yielded very similar diagnostic performance and limitations of ALAD. Further studies are necessary to evaluate this relationship further.

Validation of aorta-lesion-attenuation difference on preoperative contrast-enhanced computed tomography scan to differentiate between malignant and benign oncocytic renal tumors.

OBJECTIVES: We previously noted that the aorta-lesion-attenuation difference (ALAD) determined on CT scan discriminated well between chromophobe RCC and oncocytoma. The current evaluation seeks to validate these initial findings in a second cohort of nephrectomy patients. METHODS: A retrospective review of preoperative CT scans and surgical pathology was performed on patients undergoing nephrectomy for small, solid renal masses. ALAD was calculated by measuring the difference in Hounsfield units (HU) between the aorta and the lesion of interest on the same image slice on preoperative CT scan. The discriminative ability of ALAD to differentiate malignant pathology from oncocytoma was evaluated by sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and area under curve (AUC) using ROC analysis. RESULTS: Twenty-one preoperative CT scans and corresponding pathology reports were reviewed and included in the validation cohort. ALAD values were calculated during the excretory and nephrographic phases. Compared to the training cohort, patients in the validation cohort were significantly older (62 versus 59 years old), had larger tumors (3.7 versus 2.7 cm), and higher stage disease (59% versus 79% T1a disease). Nephrographic ALAD was able to differentiate malignant pathology from oncocytoma in the training and validation cohorts with a sensitivity of 84% versus 73%, specificity of 86% and 67%, PPV of 98% versus 91%, and NPV of 33% versus 35%. The AUC for malignant pathology versus oncocytoma in the validation cohort was 0.72 (95% CI 0.63-0.82). Nephrographic ALAD was able to differentiate chromophobe RCC from oncocytoma in the training and validation cohorts with a sensitivity of 100% versus 67%, specificity of 86% versus 67%, PPV of 75% versus 43%, and NPV of 100% versus 84%. The AUC for chromophobe RCC versus oncocytoma in the validation cohort was 0.72 (95% CI 0.48-0.96). CONCLUSIONS: The ability of ALAD to discriminate between chromophobe RCC and oncocytoma was diminished in the validation cohort compared to the training cohort, but remained significant. The current findings support further investigation in the role of ALAD in the management of patients with indeterminate diagnoses of oncocytic neoplasm.

A narrative review of the history and evidence-base for the timing of orchidopexy for cryptorchidism.

INTRODUCTION: Consensus recommendations for surgical management of cryptorchidism recommend orchidopexy between 6 and 18 months of age. The COVID-19 pandemic has impacted elective surgical scheduling. OBJECTIVE: In response to the COVID-19 pandemic, we sought to review the available data regarding the natural history, surgical management, and infertility- and cancer-related risks associated with cryptorchid testes. The purpose of this review is to provide parents, referring providers, and surgeons with information to inform their decisions to proceed with or delay orchidopexy. METHODS: A retrospective review and analysis of all available articles relevant to the natural history, surgical management, and infertility- and cancer-related risks of cryptorchidism present on PubMed, SCOPUS, and Cochrane Library was conducted. RESULTS: The quality of historic literature pertaining to the effect of cryptorchidism on fertility and malignancy differ, with poorer data available on fertility. Cryptorchid testes may show histologic differences as early as birth, and some of these changes may have prognostic value in future fertility. Formerly unilateral cryptorchid men have slightly but not significantly reduced paternity rates compared to the general population. Cryptorchid testes have an increased risk of germ cell carcinogenesis, and robust data suggest the risk for malignancy in cryptorchid testes increases substantially after puberty. CONCLUSION: The current body of evidence regarding the risks for future infertility and testicular cancer support the consensus recommendations for surgical correction of cryptorchidism between 6 and 18 months of age. During the uncertain time of the COVID-19 pandemic, decision for orchidopexy is a shared-decision between physician and parent. For an infant or young boy with a unilateral undescended testes, delaying orchidopexy several months until a time of decreased exposure risk is unlikely to result in substantial or sustained fertility or malignant risks.