Society of Abdominal Radiology (SAR) and European Society of Urogenital Radiology (ESUR) joint consensus statement for MR imaging of placenta accreta spectrum disorders.

OBJECTIVES: This study was conducted in order to establish the joint Society of Abdominal Radiology (SAR) and European Society of Urogenital Radiology (ESUR) guidelines on placenta accreta spectrum (PAS) disorders and propose strategies to standardize image acquisition, interpretation, and reporting for this condition with MRI. METHODS: The published evidence-based data and the opinion of experts were combined using the RAND-UCLA Appropriateness Method and formed the basis for these consensus guidelines. The responses of the experts to questions regarding the details of patient preparation, MRI protocol, image interpretation, and reporting were collected, analyzed, and classified as "recommended" versus "not recommended" (if at least 80% consensus among experts) or uncertain (if less than 80% consensus among experts). RESULTS: Consensus regarding image acquisition, interpretation, and reporting was determined using the RAND-UCLA Appropriateness Method. The use of a tailored MRI protocol and standardized report was recommended. CONCLUSIONS: A standardized imaging protocol and reporting system ensures recognition of the salient features of PAS disorders. These consensus recommendations should be used as a guide for the evaluation of PAS disorders with MRI. KEY POINTS: • MRI is a powerful adjunct to ultrasound and provides valuable information on the topography and depth of placental invasion. • Consensus statement proposed a common lexicon to allow for uniformity in MRI acquisition, interpretation, and reporting of PAS disorders. • Seven MRI features, namely intraplacental dark T2 bands, uterine/placental bulge, loss of low T2 retroplacental line, myometrial thinning/disruption, bladder wall interruption, focal exophytic placental mass, and abnormal vasculature of the placental bed, reached consensus and are categorized as "recommended" for diagnosing PAS disorders.

Wilms Tumor of the Uterus.

Wilms tumor (WT) is an uncommon malignant neoplasm that occurs predominantly in the kidney of pediatric patients; its extrarenal counterpart is exceedingly rare. We present the case of an adult female diagnosed with uterine WT. Following hysterectomy due to a uterine mass, histopathologic examination demonstrated a triphasic malignancy composed of epithelial, stromal, and blastemal elements. The characteristic morphologic features, which were supported by immunohistochemical analysis, were diagnostic of WT of the uterus. A summary of the main clinicopathologic parameters, along with a review of all previously reported cases, are described.

A Comprehensive Approach to Hepatic Vascular Disease.

The liver has a complex vascular supply, which involves the inflow of oxygenated blood through the hepatic artery (systemic circulation) and deoxygenated blood through the portal vein (portal circulation), as well as the outflow of deoxygenated blood through the hepatic veins to the inferior vena cava. A spectrum of vascular variants can involve the liver. Some of these variants may result in areas of enhancement that can mimic more serious pathologic conditions. In this article, the authors discuss a spectrum of variants and pathologic conditions that may involve the liver vasculature. These include variants, anomalies, and diseases involving the portal vein, such as rudimentary portal vein, thrombosis, cavernous transformation, thrombotic angiitis, thrombophlebitis, transient hepatic attenuation difference or transient hepatic intensity difference, portal venous aneurysm, and portal vein gas. The hepatic artery can be involved by various diseases, including thrombosis, stenosis, and aneurysm or pseudoaneurysm. Unusual "third inflow" sources of venous inflow are also discussed, including aberrant right gastric vein, aberrant left gastric vein, epigastric-paraumbilical veins, and cholecystic vein. A spectrum of variants and diseases involving the inferior vena cava and hepatic veins, including thrombosis, Budd-Chiari syndrome, veno-occlusive disease, stenosis, torsion, congestive hepatopathy, and peliosis hepatis, are discussed. Vascular shunts are illustrated, including portosystemic shunts (intra- and extrahepatic), arterioportal shunt, shunts of hereditary hemorrhagic telangiectasia, and acquired arteriovenous fistula. Familiarity with the pathogenesis and imaging features of these vascular entities can aid radiologic diagnoses and guide appropriate patient management. ©RSNA, 2017.

Fibromyxoid Nephrogenic Adenoma: A Series of 43 Cases Reassessing Predisposing Conditions, Clinical Presentation, and Morphology.

Nephrogenic adenoma is a benign epithelial lesion of the genitourinary tract that arises from the reimplantation and proliferation of shed renal tubular cells in areas of urothelial injury and denudation. Fibromyxoid nephrogenic adenoma is a rare variant that consists of compressed spindle-shaped renal epithelial cells in a fibromyxoid background. Only 14 observations of this variant are reported in the literature. We performed a retrospective analysis of fibromyxoid nephrogenic adenomas from 3 large reference centers. We identified 43 lesions in 6 women and 36 men (2 in 1 man) with a median age of 72 years (range, 31 to 94 y). Median lesion size was 0.7 cm (range, 0.2 to 5 cm). Nephrogenic adenomas were in the bladder (n=15), prostate/prostatic urethra (n=14), kidney (n=7), ureter (n=3), penile urethra (n=3), and urethral diverticulum (n=1). One of the kidney lesions developed in an end-stage kidney and radiologically mimicked cancer. Of 37 patients with information, 36 had predisposing conditions including prior biopsy, transurethral resection of bladder tumor, resection, Foley catheter, BCG treatment, urinary stones, (chemo)radiation, or diverticulum. Only 4/37 (10.8%) had a history of prior irradiation. Fifteen lesions had pure fibromyxoid morphology and 28 were admixed classic and fibromyxoid patterns. Three nephrogenic adenomas involved prostatic stroma, 3 renal sinus fat, 2 muscularis propria (1 bladder, 1 renal pelvis), 1 perinephric fat, and 1 corpus spongiosum. Ten fibromyxoid nephrogenic adenomas were intermixed with urothelial carcinoma, 1 with prostate adenocarcinoma, and 1 with malignant melanoma. By immunohistochemistry, PAX8 was positive in all the examined lesions (n=31). Napsin A was negative in all examined fibromyxoid nephrogenic adenomas (n=30). Twenty of them had classic nephrogenic adenoma component which was positive for napsin A. Similar to classic nephrogenic adenoma, fibromyxoid nephrogenic adenoma can occur anywhere along the urinary tract and is associated with a prior history that causes urothelial injury. In nearly a quarter of the cases, fibromyxoid nephrogenic adenoma extended beyond the lamina propria. Unlike previously suggested, fibromyxoid nephrogenic adenoma is not specifically related to prior radiation therapy. Awareness of this variant is important to avoid misdiagnosis and overtreatment.