Complex surgery and perioperative systemic therapy for genitourinary cancer of the retroperitoneum.

Objective: The purpose of the present guideline is to recommend surgical or systemic treatment for metastatic testicular cancer; T3b or T4, or node-positive, and metastatic renal cell cancer (rcc); and T3, T4, or node-positive upper tract urothelial (utuc) cancer. Methods: Draft recommendations were formulated based on evidence obtained through a systematic review of randomized controlled trials, comparative retrospective studies, and guideline endorsement. The draft recommendations underwent an internal review by clinical and methodology experts, and an external review by clinical practitioners. Results: The primary literature search yielded eight guidelines, five systematic reviews, and twenty-seven primary studies that met the eligibility criteria. Conclusions: Cytoreductive nephrectomy should no longer be considered the standard of care in patients with T3b or T4, or node-positive, and metastatic rcc. Eligible patients should be treated with systemic therapy and have their primary tumour removed only after review at a multidisciplinary case conference (mcc). Adjuvant sunitinib after surgery is not recommended. Patients with venous tumour thrombus should be considered for surgical intervention. Patients with T3, T4, or node-positive utuc should have their tumour removed without delay. Decisions concerning lymph node dissection should be done at a mcc and be based on stage, expertise, and imaging. Adjuvant systemic treatment is recommended for resected high-risk utuc. Patients with metastasis-positive testicular cancer with residual tumour after systemic treatment should be treated at specialized centres. For all complex retroperitoneal surgeries, the evidence shows that higher-volume centres are associated with lower rates of procedure-related mortality, and patients should be referred to higher-volume centres for surgical resection.

Contemporary update on imaging of cystic renal masses with histopathological correlation and emphasis on patient management.

This article presents an updated review of cystic renal mass imaging. Most cystic renal masses encountered incidentally are benign and can be diagnosed confidently on imaging and require no follow-up. Hyperattenuating masses discovered at unenhanced or single-phase enhanced computed tomography (CT) measuring between 20-70 HU are indeterminate and can be further investigated first by using ultrasound and, then with multi-phase CT or magnetic resonance imaging (MRI); as the majority represent haemorrhagic/proteinaceous cysts (HPCs). Dual-energy CT may improve differentiation between HPCs and masses by suppressing unwanted pseudo-enhancement observed with conventional CT. HPCs can be diagnosed confidently when measuring >70 HU at unenhanced CT or showing markedly increased signal on T1-weighted imaging. Although the Bosniak criteria remains the reference standard for diagnosis and classification of cystic renal masses, histopathological classification and current management has evolved: multilocular cystic renal cell carcinoma (RCC) has been reclassified as a cystic renal neoplasm of low malignant potential, few Bosniak 2F cystic masses progress radiologically during follow-up; RCC with predominantly cystic components are less aggressive than solid RCC; and Bosniak III cystic masses behave non-aggressively. These advances have led to an increase in non-radical management or surveillance of cystic renal masses including Bosniak 3 lesions. Tubulocystic RCC is a newly described entity with distinct imaging characteristics, resembling a pancreatic serous microcystadenoma. Other benign cystic masses including: mixed epithelial stromal tumours (MEST) are now considered in the spectrum of cystic nephroma and angiomyolipoma (AML) with epithelial cysts (AMLEC) resemble a fat-poor AML with cystic components.

Multiparametric MRI of the anterior prostate gland: clinical-radiological-histopathological correlation.

Anterior prostate cancer (APC) is defined as a tumour in which more than half of malignant tissue is located anterior to the urethra. APCs are increasingly recognized as clinically important, particularly in patients undergoing active surveillance and for patients with negative non-targeted systematic transrectal ultrasound (TRUS)-guided biopsies but with persistent clinical suspicion of cancer. Multiparametric (mp) MRI has a crucial role for the diagnosis of anterior tumours, eventual histological sampling of suspicious lesions using image-guided targeted biopsy techniques, and potentially, to improve local staging of disease. mpMRI is accurate for the detection of APC and for differentiation of tumour from other anterior prostatic structures including benign prostatic hyperplasia (BPH) and the anterior fibromuscular stroma (AFMS). Characterization and reporting of APC should rely on the recently revised Prostate Imaging and Data Reporting System (PI-RADS) version 2.0 document. T2-weighted (T2W) imaging is emphasized as the determining sequence for assessment of the anterior prostate and specific features for APC on T2W imaging include: ill-defined/spiculated margin, lenticular shape, anterior/inferior location, and growth pattern (invasion of urethra or AFMS and crossing midline). Functional imaging, mainly with diffusion-weighted imaging, is also contributory and improves the sensitivity for detection of APC compared to T2W imaging alone. APCs commonly show positive surgical margins after radical prostatectomy and staging of disease extent using conventional clinical parameters is limited. mpMRI may have a future role to improve local staging of APC. This review illustrates the importance of mpMRI in APC using a clinical-radiological-histopathological approach.

Multiparametric MRI of solid renal masses: pearls and pitfalls.

Functional imaging [diffusion-weighted imaging (DWI) and dynamic contrast enhancement (DCE)] techniques combined with T2-weighted (T2W) and chemical-shift imaging (CSI), with or without urography, constitutes a comprehensive multiparametric (MP) MRI protocol of the kidneys. MP-MRI of the kidneys can be performed in a time-efficient manner. Breath-hold sequences and parallel imaging should be used to reduce examination time and improve image quality. Increased T2 signal intensity (SI) in a solid renal nodule is specific for renal cell carcinoma (RCC); whereas, low T2 SI can be seen in RCC, angiomyolipoma (AML), and haemorrhagic cysts. Low b-value DWI can replace conventional fat-suppressed T2W. DWI can be performed free-breathing (FB) with two b-values to reduce acquisition time without compromising imaging quality. RCC demonstrates restricted diffusion; however, restricted diffusion is commonly seen in AML and in chronic haemorrhage. CSI must be performed using the correct echo combination at 3 T or T2* effects can mimic intra-lesional fat. Two-dimensional (2D)-CSI has better image quality compared to three-dimensional (3D)-CSI, but volume averaging in small lesions can simulate intra-lesional fat using 2D techniques. SI decrease on CSI is present in both AML and clear cell RCC. Verification of internal enhancement with MRI can be challenging and is improved with image subtraction. Subtraction imaging is prone to errors related to spatial misregistration, which is ameliorated with expiratory phase imaging. SI ratios can be used to confirm subtle internal enhancement and enhancement curves are predictive of RCC subtype. MR urography using conventional extracellular gadolinium must account for T2* effects; however, gadoxetic acid enhanced urography is an alternative. The purpose of this review it to highlight important technical and interpretive pearls and pitfalls encountered with MP-MRI of solid renal masses.

Ten uncommon and unusual variants of renal angiomyolipoma (AML): radiologic-pathologic correlation.

Classic (triphasic) renal angiomyolipoma (AML) is currently classified as a neoplasm of perivascular epithelioid cells. For diagnosis of AML, the use of thin-section non-contrast enhanced CT (NECT) improves diagnostic accuracy; however, identifying gross fat within a very small AML is challenging and often better performed with chemical-shift MRI. Although the presence of gross intra-tumoural fat is essentially diagnostic of AML; co-existing intra-tumoural fat and calcification may represent renal cell carcinoma (RCC). Differentiating AML from retroperitoneal sarcoma can be difficult when AML is large; the feeding vessel and claw signs are suggestive imaging findings. AML can haemorrhage, with intra-tumoural aneurysm size >5 mm a more specific predictor of future haemorrhage than tumor size >4 cm. Diagnosis of AML in the setting of acute haemorrhage is complex; comparison studies or follow-up imaging may be required. Not all AML contain gross fat and imaging features of AML without visible fat overlap with RCC; however, homogeneity, hyperdensity at NECT, low T2-weighted signal intensity and, microscopic fat are suggestive features. Patients with tuberous sclerosis often demonstrate a combination of classic and minimal fat AML, but are also at a slightly increased risk for RCC and should be imaged cautiously. Several rare pathological variants of AML exist including AML with epithelial cysts and epithelioid AML, which have distinct imaging characteristics. Classic AML, although benign, can be locally invasive and the rare epithelioid AML can be frankly malignant. The purpose of this review is to highlight the imaging manifestations of 10 uncommon and unusual variants of AML using pathological correlation.

Pitfalls of adrenal imaging with chemical shift MRI.

Chemical shift (CS) MRI of the adrenal glands exploits the different precessional frequencies of fat and water protons to differentiate the intracytoplasmic lipid-containing adrenal adenoma from other adrenal lesions. The purpose of this review is to illustrate both technical and interpretive pitfalls of adrenal imaging with CS MRI and emphasize the importance of adherence to strict technical specifications and errors that may occur when other imaging features and clinical factors are not incorporated into the diagnosis. When performed properly, the specificity of CS MRI for the diagnosis of adrenal adenoma is over 90%. Sampling the in-phase and opposed-phase echoes in the correct order and during the same breath-hold are essential requirements, and using the first echo pair is preferred, if possible. CS MRI characterizes more adrenal adenomas then unenhanced CT but may be non-diagnostic in a proportion of lipid-poor adenomas; CT washout studies may be able to diagnose these lipid-poor adenomas. Other primary and secondary adrenal tumours and supra-renal disease entities may contain lipid or gross fat and mimic adenoma or myelolipoma. Heterogeneity within an adrenal lesion that contains intracytoplasmic lipid could be due to myelolipoma, lipomatous metaplasia of adenoma, or collision tumour. Correlation with previous imaging, other imaging features, clinical history, and laboratory investigations can minimize interpretive errors.