A Non-Invasive Scoring System to Differential Diagnosis of Clear Cell Renal Cell Carcinoma (ccRCC) From Renal Angiomyolipoma Without Visible Fat (RAML-wvf) Based on CT Features

Comparison of perioperative efficacy and indications between laparoscopic capsule-preserving resection and partial nephrectomy for renal angiomyolipoma: a decade-long retrospective study

BACKGROUND

This study aims to compare and evaluate the clinical efficacy of laparoscopic capsule-preserving resection (LCPR) and laparoscopic partial nephrectomy (LPN) in the treatment of renal angiomyolipoma (RAML). Multivariate regression analysis was employed to identify patient characteristics that are most suited for LCPR.

METHODS

We retrospectively analyzed the clinical data of 209 patients diagnosed with RAML and treated surgically at our hospital between January 2010 and December 2023. The patients were divided into two groups: 102 in the LCPR group and 109 in the LPN group. Preoperative factors (e.g., age, sex, glomerular filtration rate (GFR), and tumor location), intraoperative factors (e.g., ischemia time and blood loss), and postoperative outcomes (e.g., extubation time, hospitalization duration, and renal function) were recorded. Chi-square tests, independent sample t-tests, and rank-sum tests were applied where appropriate. Logistic regression analysis was used to identify patient characteristics associated with suitability for LCPR.

RESULTS

No significant differences were observed in the preoperative baseline characteristics (age, sex, or tumor size) between the two groups (P > 0.05). All surgeries in the LCPR group were successfully completed, and no patients required conversion to open surgery. The average operation time was 118.56 ± 44.49 min, the warm ischemia time was 17.40 ± 7.51 min, and the intraoperative blood loss was 197.35 ± 282.64 ml, all of which were significantly lower than in the LPN group (P < 0.05). The incidence of postoperative complications in the LCPR group was 21.6% for Clavien-Dindo grade I and 2.9% for higher-grade complications, significantly lower than the LPN group (33.6% and 8.4%, respectively; P = 0.02). The average postoperative hospital stay in the LCPR group was 6.42 ± 3.01 days, significantly shorter than in the LPN group (9.27 ± 3.24 days; P < 0.001). The average GFR 1-3 days after surgery and the renal function grade 3 months post-surgery were significantly better in the LCPR group compared to the LPN group (P = 0.001). Multivariate regression analysis identified that patients with low preoperative serum creatinine levels, mild clinical symptoms, tumors smaller than 6 cm, and tumors located near the middle of the kidney were more likely to undergo LCPR (P < 0.05). These patients also experienced less renal function deterioration post-surgery.

CONCLUSIONS

Laparoscopic capsule-preserving tumor resection offers significant clinical advantages in treating renal angiomyolipoma. Compared to traditional laparoscopic partial nephrectomy, LCPR results in less intraoperative blood loss, shorter warm ischemia times, lower complication rates, and faster postoperative recovery. Patients with mild clinical symptoms, small tumors, or tumors located in complex regions such as the renal hilum are more suitable for this surgical approach, making it a promising technique for broader clinical application.

Differential diagnosis of clear cell renal cell carcinoma with low signal intensity on T2WI from angiomyolipoma without visible fat on MR imaging

PURPOSE

This study aimed to determine the potential of magnetic resonance imaging (MRI) parameters in differentiating between angiomyolipoma without visible fat (AML.wovf) and clear cell renal cell carcinoma (ccRCC) with low signal intensity on T2-weighted imaging (T2WI).

MATERIALS AND METHODS

This is a retrospective study involving 36 cases of ccRCC and 17 cases of AML.wovf from September 2016 to July 2023. All patients underwent histological examination on resected specimens and contrast-enhanced magnetic resonance imaging (CE-MRI). Clinical characteristics such as age, gender, and symptoms of hematuria and lumbago were recorded. A panel of MRI parameters were analyzed, including the tumor growth patterns, the wedge-shaped sign, pseudocapsule formation, the arterial-to-delayed enhancement ratio (ADER), and the apparent diffusion coefficient (ADC). The potential of these MRI parameters in distinguishing ccRCC from AML.wovf was finally determined and visualized in a nomogram.

RESULTS

There were no significant differences in age, gender, and clinical symptoms between the ccRCC and AML.wovf groups. The wedge-shaped sign was more prevalent in patients with AML.wovf (p = 0.027), while pseudocapsule formation was mainly observed in cases of ccRCC (p < 0.001). Quantitative MRI revealed a significantly lower ADC in patients with AML.wovf (p = 0.007). Pseudocapsule formation (OR = 140.29, p = 0.004), the wedge-shaped sign (OR = 0.05, p = 0.047), and ADC (OR = 36.22, p = 0.037) were independent predictors for differentiating between AML.wovf and ccRCC, and their combination demonstrated the highest diagnostic accuracy, with an area under the curve (AUC) of 0.913 in the receiver operating characteristic (ROC) analysis.

CONCLUSION

A combination of MRI parameters, including the wedge-shaped sign, pseudocapsule formation, and ADC, can accurately differentiate between AML.wovf and ccRCC.

CT-based scoring system for diagnosing eosinophilic solid and cystic renal cell carcinoma versus clear cell renal cell carcinoma

Eosinophilic solid and cystic renal cell carcinoma (ESC-RCC) is rare and often misdiagnosed as clear cell renal cell carcinoma (ccRCC). Therefore, a CT-based scoring system was developed to improve differential diagnosis. Retrospectively, 25 ESC-RCC and 176 ccRCC cases, were collected. The two groups were matched on a 1:2 basis using the propensity-score-matching (PSM) method, with matching factors including sex and age. Finally, 25 ESC-RCC and 50 ccRCC cases were included and randomly divided into a training cohort (52 cases) and a validation cohort (23 cases). Logistic regression identified significant factors, constructed the primary model, and assigned weights for the scoring model. Diagnostic performance was compared using receiver operating characteristic curves, dividing points into three intervals. Multifactorial logistic regression identified three independent factors: intra-tumour necrosis (3 points), degree of corticomedullary phase (CMP) enhancement (3 points), and pseudocapsule (2 points). The primary model's area under the curve (AUC) value was 0.954 (95% confidence interval [CI]: 0.857-0.993, P < 0.001), with 85.7% sensitivity and 94.1% specificity. The scoring model's AUC value for the training cohort was 0.950 (95% CI: 0.852-0.991, P < 0.001), with 77.1% sensitivity and 100% specificity at a cut-off of 4 points. The validation cohort's AUC was 0.942 (95% CI: 0.759-0.997, P < 0.001). The scoring system intervals were: ≥0 to < 2 points, ≥ 2 to ≤ 3 points, and > 3 to ≤ 8 points. Higher scores correlated with increased ccRCC incidence and decreased ESC-RCC incidence.The limitation of this study is the small sample size. A CT-based scoring system effectively differentiates ESC-RCC from ccRCC.

A diagnostic scoring model of ENKTCL in the nose-Waldeyer's ring based on logistic regression: Differential diagnosis from DLBCL

Objective

To establish a logistic regression model based on CT and MRI imaging features and Epstein-Barr (EB) virus nucleic acid to develop a diagnostic score model to differentiate extranodal NK/T nasal type (ENKTCL) from diffuse large B cell lymphoma (DLBCL).

Methods

This study population was obtained from two independent hospitals. A total of 89 patients with ENKTCL (n = 36) or DLBCL (n = 53) from January 2013 to May 2021 were analyzed retrospectively as the training cohort, and 61 patients (ENKTCL=27; DLBCL=34) from Jun 2021 to Dec 2022 were enrolled as the validation cohort. All patients underwent CT/MR enhanced examination and EB virus nucleic acid test within 2 weeks before surgery. Clinical features, imaging features and EB virus nucleic acid results were analyzed. Univariate analyses and multivariate logistic regression analyses were performed to identify independent predictors of ENKTCL and establish a predictive model. Independent predictors were weighted with scores based on regression coefficients. A receiver operating characteristic (ROC) curve was created to determine the diagnostic ability of the predictive model and score model.

Results

We searched for significant clinical characteristics, imaging characteristics and EB virus nucleic acid and constructed the scoring system via multivariate logistic regression and converted regression coefficients to weighted scores. The independent predictors for ENKTCL diagnosis in multivariate logistic regression analysis, including site of disease (nose), edge of lesion (blurred), T2WI (high signal), gyrus like changes, EB virus nucleic acid (positive), and the weighted score of regression coefficient was 2, 3, 4, 3, 4 points. The ROC curves, AUCs and calibration tests were carried out to evaluate the scoring models in both the training cohort and the validation cohort. The AUC of the scoring model in the training cohort were 0.925 (95% CI, 0.906-0.990) and the cutoff point was 5 points. In the validation cohort, the AUC was 0.959 (95% CI, 0.915-1.000) and the cutoff value was 6 points. Four score ranges were as follows: 0-6 points for very low probability of ENKTCL, 7-9 points for low probability; 10-11 points for middle probability; 12-16 points for very high probability.

Conclusion

The diagnostic score model of ENKTCL based on Logistic regression model which combined with imaging features and EB virus nucleic acid. The scoring system was convenient, practical and could significantly improve the diagnostic accuracy of ENKTCL and the differential diagnosis of ENKTCL from DLBCL.