[Application value of diffusion-weighted imaging signal pattern in the qualitative diagnosis of renal lesions with T(2)WI hypointensity].

Objective: To analyze the diagnostic value of diffusion-weighted imaging (DWI) signal pattern in renal lesions with T(2)WI hypointensity. Methods: Retrospective analysis was performed on DWI imaging datasets of 135 renal lesions with hypointentsity on T(2)WI confirmed by surgery, biopsy, or follow-up in the First Medical Center of Chinese PLA General Hospital from February 2016 to February 2017.One hundred and thirty-five renal lesions,43 benign lesions(age from 28 to 70 years,mean age was 43.5 years, male 18 lesions and female 25 lesions) and 92 malignant lesions (age from 17 to 86 years, mean age was 54.1 years, male 62 lesions and female 30 lesions). DWI signal pattern was classified into six categories: homogeneously high signal, homogeneously low signal, heterogeneously high signal, high halo signal, high halo and nodular signal, and high nodular signal. The agreement between two observers were tested using kappa statistic. The statistical difference between DWI signal characteristics in benign and malignant lesions was analyzed with Chi-Square test. Diagnostic efficacy in differentiation of benign and malignant renal lesions using DWI signal pattern were calculated. Results: One hundred and thirty-five lesions were detected in 135 cases with T(2)WI hypointensity. There were 43 benign lesions and 92 malignant lesions. The agreement between two observers was very good (kappa value=0.878 6). In renal T(2)WI hypointensity lesions, the proportion of DWI homogeneous high signal, homogeneous low signal, heterogeneous high signal, high halo signal, high halo and nodular signal, high nodular signal was 4.7% (2/43), 25.6% (11/43), 30.2% (13/43), 18.6% (8/43), 11.6% (5/43), 9.3% (4/43), respectively. The proportion of malignant lesions was 10.9% (10/92), 0 (0/92), 17.4% (16/92), 13.0% (12/92), 56.5% (52/92) and 2.2% (2/92), respectively. The difference of high halo and nodules signal and homogeneous low signal was statistically significant (all P<0.01). The sensitivity, specificity, positive prediction value (PPV) and negative prediction value (NPV) of high halo and nodular signal for malignancy were 56.5% (52/92), 88.4%(38/43), 91.2% (52/57) and 48.7%(38/78), respectively and homogeneous low signal for benign lesions were 25.6% (11/43), 100.0% (92/92), 100.0% (11/11) and 74.2% (92/124), respectively. Conclusions: DWI signal features may facilitated the accurate diagnosis of renal lesions with T(2)WI hypointensity. Malignant lesions exhibit a higher propensity with high halo and nodular signal on DWI while benign lesions with homogeneous low signal.

[Application of multimode MRI in prediction of nuclear grade of clear cell renal cell carcinoma].

Objective: To investigate the predictive value of multimode MRI features for nuclear grade of clear cell renal cell carcinoma (ccRCC). Methods: From January 2016 to October 2017, 381 patients (387 tumors) with ccRCC proven by pathology in Chinese PLA General Hospital First Medical Center were enrolled (male 293, female 88, age 24-87 years old). The clinical and imaging data of these patients were retrospectively analyzed, including clinical information (gender, age, BMI, smoke, hypertension) and preoperative renal MRI. Pre-and post-contrast MRI features were subjectively scored. The largest diameter of each lesion was measured. Two-sample t-test,Chi-squared test and binuary Logistic regression analysis were used to evaluate the predictive efficacy of clinical and MRI data. Results: According to WHO/ISUP nuclear grade system,all ccRCCs (n=387) were divided into low grade (n=322) and high grade group (n=65). Between two groups, there were significant differences in age and diameter((54±12) vs (59±10) years old, P=0.001; (4.1±2.2) vs (6.2±3.0) cm, P<0.01). In MRI scores,there were significant differences in scores of pseudocapsule, shape and margin,hemorrhage,enhancement degree,cystic-solid,intratumoral vessel,peritumoral vessel, renal sinus invasion, vein thrombosis, lymphadenopathy, necrosis, perinephric invasion and metastasis, DWI signal intensity between high grade group and low grade group (all P<0.01). Binuary Logistic regression analysis showed that shape and margin, enhancement degree and DWI signal intensity were independent predictors for high grade ccRCC (OR=0.181, 95%CI 0.049-0.666; OR=0.393, 95%CI 0.182-0.846; OR=0.336, 95%CI 0.155-0.728). A nomogram model for predicting the risk of high grade ccRCC was constructed. Conclusions: Multimode MRI features can differentiate low grade and high grade ccRCC. The nomogram developed in this study might aid urologist in the pre-operative prediction of nuclear grade of ccRCC,which might contribute to developing treatment strategy.

[Magnetic resonance imaging findings and differential diagnosis of renal epithelioid angiomyolipoma comparing with renal no-epithelioid angiomyolipoma].

Objective: To investigate whether MRI findings can differentiate renal epithelioid angiomyolipoma (EAML) from renal no-epithelioid (typical) angiomyolipoma. Methods: A total of 44 patients were collected from General Hospital of PLA.These cases were obtained from January 2009 to June 2015.To retrospectively analyze these mainly MRI findings among 12 cases of EAML (age from 27 to 61 years, male 2 cases, female 10 cases, mean age was 46.7 years); 32 cases of renal no-epithelioid AML (age from 34 to 70 years old, male 9 cases, female 23 cases, mean age was 53.4 years old) as case control study. MRI findings included gender, T(2)WI, the signal on gross fat, pseudocapsle, necrosis or cystic degeneration, DWI, hemorrhage and the peak in three phases of dynamic enhancement.All data were analyzed statistically using SPSS version 19.0 (IBM, Armonk, NY, USA). χ(2) test and a single order chart were used to analyze the enumeration data. Results: Comparing with renal no-epithelioid angiomyolipoma, minimal fat, necrosis or cystic degeneration and hemorrhage were statistical significance. P values were 0.002, 0.007, 0.025, respectively.Gender, solid components of tumors on T(2)WI, the signal of DWI, pesudocapsule and the peak of enhancement had no statistical significance. P values were 0.863, 0.053, 0.479, 0.460, respectively. Conclusion: Comparing with renal no-epithelioid AML, necrosis or cystic degeneration and hemorrhage with minimal fat are characteristic MRI findings of EAML.

[Clinical and pathologic analysis of 414 cases of renal angiomyolipomain in a single institution].

Objective: To study the different clinicopathological characteristics between classic and epithelioid renal angiomyolipoma, and the relationships between clinicopathological characteristics and biological behaviors as basis for clinical treatment. Methods: The clinicopathological and follow-up data for the patients diagnosed with renal angiomyolipoma between 2004 and 2011 were retrospectively reviewed and analyzed. Results: There were 414 cases of renal angiomyolipoma diagnosed over 8 years ago, accounting for 8.1% (414/5 287) of all renal parenchymal tumors. The patients included 122 male and 292 female (male-to-female ratio of 1.0∶2.4), mean age 44.0 years (range 15-74 years). Of these, 195(47.1%) tumors occurred in the left kidney, 212(51.2%) in the right kidney and seven (1.7%) were bilateral. Clinically, some cases presented with hypochondrial pain, hematuria or palpable masses. Histologically, 394(95.2%) were classic angiomyolipoma, 20(4.8%) were epithelioid angiomyolipoma; 54, 23 and 7 cases had hemorrhage, necrosis and cystic degeneration, respectively; and 5, 30 and 14 cases had perirenal fat invasion, atypical cells and polymorphic/giant tumor cell. There was a positive correlation between atypical cells and epithelioid tumor type, respectively. The other clinicopathological parameters did not correlate with histological type. Follow-up data was available in 360 patients, with follow-up period of 3 to 99 months. One case died from other causes. The remaining patients were free of disease. Conclusions: Angiomyolipoma is a common renal parenchyma tumor. Clinically, it is usually biologically benign. Histologically, it can be either classic or epithelioid types. The epithelioid type should be differentiated from the classic renal cell carcinoma, Mit family translocation renal tumor and renal hemangioblastoma. Atypical cells, more commonly found in the epithelioid angiomyolipoma, do not affect the clinical prognosis of patients.

[MRI findings of renal cell carcinoma associated with Xp11.2 translocations/TFE3 gene fusions].

Objective: To analyze MRI findings of renal cell carcinoma associated with Xp11.2 translocation-TFE gene fusion(Xp11.2 RCC). Methods: MR imaging features of eleven patients with pathologically-proved Xp11.2 RCC were retrospectively analyzed from December 2008 to December 2015. The following MRI features of the lesions were analyzed in the study: location, maximal diameter, signal intensity, hemorrhage, necrosis, cystic change, enhancement features and metastasis. The data was analyzed by using t test. Results: Four men and seven women (mean age, 35.2 years; age range, 15-49 years) were included. Tumors occurred in the right kidney in 5 cases and the left kidney in 6 cases. On T1WI tumors showed heterogeneously hypo-intensity and iso-intensity, hyper-intensity in 10 cases, 1 cases, respectively. On T2WI tumors showed heterogeneously slight hypo-intensity, heterogeneously slight hyper-intensity and hyper-intensity in 6 cases, 4 cases, 1 case, respectively. On DWI tumors showed hyper-intensity and heterogeneously slight hype-intensity in 2 cases, 9 cases, respectively. ADC value of the tumors were statistically significant lower than that of renal cortex(×10-3mm2/s)(1.35±0.20 vs 2.09±0.11, P<0.05). Imaging findings were suggestive of hemorrhage(n=4) or necrosis (n=1) or cystic change (n=6) or lipid(n=1) in the tumors. On dynamic contrast-enhanced imaging, tumors showed lower signal intensity change (96%±93%, 110%±86% and 103%±46%, respectively) than did renal cortex (285%±109%, 254%±97% and 225%±90%, respectively) (P<0.05). Tumor capsule showed in 7 cases. Enlarged lymph node was found in renal hilum in one case. Conclusion: MRI findings may show characteristic features of Xp11.2 RCC combined with patients' age and assist in preoperative correct diagnosis.

[Clinicopathologic characteristics of thyroid-like follicular carcinoma of the kidney: an analysis of five cases and review of literature].

Objective: To study the clinicopathologic features of thyroid-like follicular renal cell carcinoma. Methods: Clinical data were collected in 5 cases of thyroid-like follicular renal cell carcinoma. HE staining and immunohistochemistry were carried out in surgically-removed specimen to analyze the clinical and pathological features with review of the literatures. Results: The patients aged 20-55 years, with one male and four females; the tumor occurred in the left kidney in three cases and right kidney in two cases. One case had a history of thyroid papillary carcinoma 3 years ago, and the patient had left flank pain, macroscopic haematuria for 2 weeks. The rest four cases had no consciousness of clinical symptoms and signs, without history of thyroid gland surgery; the physical examination found a mass in the kidney and normal thyroid glands. Three patients underwent radical nephrectomy, and the other two patients underwent tumor partial nephrectomy. The tumors were 2-4 cm in size. They showed a solitary nodular mass of well circumscribed with taupe and gray on cut surface. Microscopically, most of tumor cells arranged in thyroid follicular pattern in different sizes, with papillary configuration in a small portion, in four cases; the follicular structure was intermixed with the papillary each half in one case. A large amount of thyroid colloid was deposited within follicule-like structure or papillary axis, lined by simple columnar cells or cubic cells, with obvious atypia, ground-glass nuclei, nuclear groove and rare mitosis. Immunohistochemical staining showed tumor cells were positive for PAX8, and negative for thyroid transcription factor 1 (TTF1) and thyroglobulin (Tg). One of five patients presented with lymph node metastases (4/4) of renal hilum the same time in the diagnosis. Five cases were followed up for 5-84 months after operation, and no tumor progression was found. Conclusions: Thyroid-like follicular renal cell carcinoma is primary renal epithelial malignant tumor. The diagnosis mainly depends on its characteristics of histological appearance, namely similar to the histological morphology of well-differentiated thyroid follicular carcinoma and papillary carcinoma, and the metastasis from the thyroid papillary or follicular carcinoma must be excluded. On the premise of clinical history, immunohistochemical markers TTF1 and Tg have certain value in the differential diagnosis.