From the archives of the AFIP: Inflammatory and nonneoplastic bladder masses: radiologic-pathologic correlation

VI steps to achieve VI-RADS assessment

Bladder cancer is categorized into nonmuscle-invasive bladder cancer (NMIBC) and muscle-invasive bladder cancer (MIBC), distinguished by the presence of detrusor muscle invasion. Urothelial cell carcinoma is the most common subtype of bladder cancer. Transurethral resection of bladder tumor (TURBT) is the standard approach for staging and managing NMIBC, while radical cystectomy remains the cornerstone treatment for MIBC. Multiparametric magnetic resonance imaging (mpMRI), comprising morphological imaging sequences (high-resolution T2-weighted images) and functional imaging sequences (dynamic contrast-enhanced images and diffusion-weighted images), serves as an ideal modality. It provides high-contrast resolution for visualizing bladder wall layers, thereby enabling proper and timely staging of bladder cancer. MRI can guide sampling resection and identify patients understaged after primary TURBT, facilitating appropriate surgical restaging. In 2018, the Vesical Imaging Reporting and Data System (VI-RADS), implementing a 5-point scale, was developed to standardize MRI protocols and reporting criteria-including tumor location, size, morphology, and invasiveness. The aim of this article is to navigate through all the steps to achieve VI-RADS assessment and to discuss practical pearls and pitfalls in the use of mpMRI. This approach can aid in pre-TURBT prediction of muscle invasion, representing an important asset in bladder cancer staging.

Radiology of fibrosis part III: genitourinary system

Fibrosis is a pathological process involving the abnormal deposition of connective tissue, resulting from improper tissue repair in response to sustained injury caused by hypoxia, infection, or physical damage. It can impact any organ, leading to their dysfunction and eventual failure. Additionally, tissue fibrosis plays an important role in carcinogenesis and the progression of cancer.Early and accurate diagnosis of organ fibrosis, coupled with regular surveillance, is essential for timely disease-modifying interventions, ultimately reducing mortality and enhancing quality of life. While extensive research has already been carried out on the topics of aberrant wound healing and fibrogenesis, we lack a thorough understanding of how their relationship reveals itself through modern imaging techniques.This paper focuses on fibrosis of the genito-urinary system, detailing relevant imaging technologies used for its detection and exploring future directions.

Ultrasound diagnosis of cystic cystitis with von Brunn's nest in two cats

Case series summary

Two cats were initially evaluated for recurrent dysuria and haematuria, which were unresponsive to antibiotic and anti-inflammatory treatments. An abdominal ultrasound revealed focal wall thickening with a severe hypoechoic multicystic parietal lesion at the bladder apex. Surgical excision of the lesion (apical cystectomy) led to complete resolution of the clinical signs in both cases. The histological findings were consistent with large cystic von Brunn's nest hyperplasia, along with foci of small glandular metaplasia. Urine and tissue cultures were negative. Cystitis cystica was diagnosed. No recurrence was reported within 2 years of surgery in both cases.

Relevance and novel information

This case series illustrates the occurrence and ultrasonographic features of a type of cystitis rarely described in animals: cystic cystitis with von Brunn's nest hyperplasia. These lesions result from chronic irritation and can lead to recurrent cystitis if not excised. Cystic cystitis has previously been described histologically in cats. To the authors' knowledge, this is the first report of macroscopic apical cystic cystitis with pre-treatment ultrasound diagnosis. Surgical resection of the hyperplastic von Brunn's nests appeared to be curative in both cases.

Cystitis glandularis mimicking a bladder tumor: A rare case report

Cystitis glandularis is a rare benign condition, occurring in only 1% of the general population, and it tends to affect males more frequently. This pathology is characterized by reactive metaplasia of the bladder's urothelium, which results from chronic and recurrent irritation of the bladder wall. Symptoms are nonspecific and primarily marked by an irritative urinary syndrome accompanied by hematuria. We present a case of a young male patient with cystitis glandularis, discovered as a result of bilateral uretero-hydronephrosis detected during an ultrasound examination subsequent to an irritative urinary syndrome. The diagnosis was initially suggested by a CT scan; it was ultimately histologically confirmed following the endoscopic resection of the tumor.

Imaging the post-treatment pelvis with gynecologic cancers

Gynecological malignancies, such as ovarian cancers, cervical cancers, and endometrial cancers, have a significant global impact. Women with gynecologic malignancies may receive a single or a combination of treatments, including surgery, chemotherapy, and radiation-based therapies. Radiologists utilize various diagnostic imaging modalities to provide the surgeon with relevant information about the diagnosis, prognosis, optimal surgical strategy, and prospective post-treatment imaging. Computerized Tomography (CT) and magnetic resonance imaging (MRI) may be used initially to evaluate and detect post-treatment complications. Although CT is primarily used for staging, MRI is commonly used for a more accurate evaluation of a tumor's size and detection of local invasion. Complications such as hematoma, abscess, inclusion cyst, seroma, tumor thrombosis, anorectovaginal fistula, and gossypiboma may occur after the three primary treatments, and systems such as the genitourinary, gastrointestinal, neurological, and musculoskeletal may be affected. In order to distinguish between early-onset and late-onset complications following gynecological treatment, radiological findings of the most common post-treatment complications will be presented in this review.

Sigmoid diverticulitis mimicking a urinary bladder tumor: A rare case report

Urothelial cell carcinomas represent the vast majority of urinary bladder tumors. However, many inflammatory and non-neoplastic conditions can mimic a urinary bladder malignancy. In that matter, diverticulitis can progress into colovesical fistula formation with a bladder wall abscess that can mimic a pseudo mass. Nonetheless, the presence of a bladder wall mass, usually requires pathologic examination. We report the case of a 60 year old woman with recurrent urinary infections due to a focal bladder mass revealing a colovesical fistula as a complication of sigmoid diverticulitis.

Tumefactive Nonneoplastic Proliferative Pseudotumors of the Kidneys and Urinary Tract: CT and MRI Findings with Histopathologic Correlation

A diverse spectrum of pathologically distinct, nonneoplastic, proliferative conditions of the kidneys and urinary tract demonstrate a expansile growth pattern similar to that of neoplasms. The renal pseudotumors include myriad causes of infections as well as rare noninfectious causes such as sarcoidosis, amyloidosis, and immunoglobulin G4-related disease (IgG4-RD). Rare entities such as cystitis cystica, endometriosis, nephrogenic adenoma, and pseudosarcomatous myofibroblastic proliferation and distinct types of prostatitis comprise tumefactive nontumorous disorders that affect specific segments of the urinary tract. The pseudotumors of the kidneys and urinary tract demonstrate characteristic histopathologic and epidemiologic features, as well as protean clinical manifestations, natural history, and imaging findings. Many patients present with genitourinary tract-specific symptoms or systemic disease. Some cases may be incidentally discovered at imaging. Some entities such as perinephric myxoid pseudotumors, IgG4-RD, fibroepithelial polyp, and nephrogenic adenoma display specific anatomic localization and disease distribution. Imaging features of multisystem disorders such as tuberculosis, sarcoidosis, and IgG4-RD provide supportive evidence that may allow precise diagnosis. Fungal pyelonephritis, xanthogranulomatous pyelonephritis, IgG4-RD, actinomycosis, and endometriosis show markedly low signal intensity on T2-weighted MR images. Although some pseudotumors exhibit characteristic imaging findings that permit correct diagnosis, laboratory correlation and histopathologic confirmation are required for definitive characterization in most cases. A high index of suspicion is a prerequisite for diagnosis. Accurate diagnosis is critical for instituting optimal management while preventing use of inappropriate therapies or interventions. Surveillance CT and MRI are frequently used for monitoring the response of pseudotumors to therapy. ©RSNA, 2023 Quiz questions for this article are available in the supplemental material.

A pictorial review of genitourinary infections and inflammations

Various infectious and inflammatory diseases affect the genitourinary system. This paper provides a review of multiple common and uncommon infectious and inflammatory conditions affecting the genitourinary system and some associated complications. These include acute infectious cystitis, emphysematous cystitis, acute pyelonephritis, emphysematous pyelonephritis, renal and perinephric abscesses, pyonephrosis, xanthogranulomatous pyelonephritis, epididymo-orchitis, vasitis, prostatitis, pelvic inflammatory disease, renal hydatid infection, renal tuberculosis, actinomycosis, Erdheim-Chester Disease, IgG4-Related Kidney Disease, urethritis and urethral strictures, ureteritis cystica, and genitourinary fistulas. Radiologists should be aware of these diseases' complications and management. Uncommon conditions must be considered when evaluating the genitourinary system.

Differences in clinical features between focal and extensive types of cystitis glandularis in patients without a previous history of urinary tract malignancy

PURPOSE

To understand the clinical differences of cystitis glandularis (CG), a proliferative disorder of urinary bladder epithelium, based on the extent of cystoscopic findings in patients without a history of urinary tract malignancy.

MATERIALS AND METHODS

We conducted a review of patients diagnosed with CG in two tertiary hospitals from 2005 to 2021. Patients with previous or concurrent history of urinary tract malignancy were excluded. Medical records, including demographics, endoscopic and all available imaging studies, and managements, were reviewed. Patients were divided into two types according to extent of the lesion, and their clinical features were compared.

RESULTS

In total, 110 patients were enrolled in the final analysis, with 36 (32.7%) classified as extensive type and 74 (67.3%) as focal type. Patients with extensive type were predominantly males and relatively younger than those with focal type (p=0.025). Voiding problems were more strongly associated and hydronephrosis caused by CG was significantly more common in the extensive type (p=0.005 and p=0.003, respectively). Multiple transurethral resection procedures were more frequently performed in the extensive type (p=0.017). Subsequent urinary tract malignancy was observed in four patients, all of whom had focal-type CG.

CONCLUSIONS

There were significant differences in clinical features between the extensive- and focal-types CG. The extensive type was more often associated with urologic complications. Meanwhile, in the focal type, subsequent urinary tract malignancy might develop during the follow-up period. Thus, thorough initial work-up and careful follow-up is necessary despite the benign nature of CG. Annual surveillance cystoscopy may be appropriate.

FDG-Avid Malakoplakia of the Ureter Mimicking Malignancy

ABSTRACT

Malacoplakia is a rare chronic granulomatous disease and frequently associated with Escherichia coli infection. We describe the contrast-enhanced CT and FDG PET/CT findings in a case of bladder and ureteral malakoplakia with E. coli urinary tract infection. Contrast-enhanced CT showed multiple enhancing mural nodules in the bladder and left ureter, ranging from several millimeters to 3.1 cm. The ureteral nodules showed significantly increased FDG uptake with SUVmax of 20.4, due to histiocyte, lymphocyte, and plasma cell infiltrates revealed by histopathology.

Comparison of the diagnostic performance of biparametric and multiparametric MRI in detecting muscle invasion of bladder cancer located at the ureteral orifice

PURPOSE

To assess the diagnostic performance of biparametric magnetic resonance imaging (bp-MRI) in predicting detrusor muscle invasion for bladder cancer (BC) located at the ureteral orifice by comparing it with the Vesical Imaging Reporting and Data System (VI-RADS) system based on multiparametric MRI (mp-MRI).

METHODS

Patients with histopathologically proven BC located at the ureteral orifice from December 2019 to November 2022 were analyzed retrospectively. Two sets, bp-MRI (set 1) and mp-MRI (set 2), were formed from the images. Both sets were evaluated independent of histopathology by three radiologists with different levels of experience in abdominal radiology. Receiver operating characteristic (ROC) curve analysis was used to assess the diagnostic performance of VI-RADS in the prediction of muscle invasion. The intraclass correlation coefficient (ICC) was used to evaluate inter-reader agreement.

RESULTS

Of 68 patients with BCs located at the ureteral orifice, 50 (48 males, median age: 72 years) met the study criteria. Out of the 50 patients, 36 had non-muscle invasive BC (pTa-T1) and 14 had muscle invasive BC (MIBC) (pT2-T4). In the comparison of VI-RADS categories with histopathologic data for MIBC detection, the area under the curve of the ROC analysis for the bp- and mp-MRI protocol was 1.000-0.986 for reader 1, 0.893-0.901 for reader 2, and 0.808-0.865 for reader 3. There was no statistically significant difference in predicting detrusor muscle invasion with the bp- and mp-MRI-based on VI-RADS categories for all readers (p = 0.126, 0.203, and 0.322, respectively). The ICCs between all the readers showed excellent agreement and were similar for both protocols.

CONCLUSION

The bp-MRI consisting of DWI and T2-WI can be used as an alternative to the mp-MRI in predicting detrusor muscle invasion for BCs located at the ureteral orifice; however, less experienced readers should exercise caution.

Extraprostatic incidental findings on prostate mpMRI: A pictorial review from the ESUR junior network

The role of multiparametric MRI (mpMRI) in prostate cancer setting is increasingly consolidated and, as a result, its usage in clinical practice is in exponential growth. However, beyond the prostate gland, several key structures are included in the field of view of mpMRI scans. Consequently, various extra-prostatic incidental findings (IFs) belonging to different anatomical systems can be accidentally recognized. Therefore, it is mandatory for a radiologist to be familiar with the wide range of pathologies potentially encountered, to guide management and avoid patient anxiety and costs due to additional work-up prompted by clinically insignificant extra-prostatic findings. With this pictorial review, we aim to illustrate a wide range of IFs that can be detected when performing mpMRI of the prostate, focusing on their imaging characteristics, differential diagnosis, and clinical relevance. Additionally, we propose the CheckDEEP, the Checklist for DEtection of ExtraProstatic findings, to be used for a thorough evaluation of target areas within each anatomical system.

p16 Immunohistochemical Expression in Nephrogenic Adenoma

Nephrogenic adenoma (NA) is a rare metaplastic entity commonly associated with a prior urothelial injury. Most are seen in the urinary bladder and a minority involve the urethra. In this study, we evaluated the expression of p16 as a surrogate marker of this entity and correlated it with clinical pathological parameters. A total of 17 cases of NA were retrospectively studied to assess the immunohistochemical expression of p16 and its value for the diagnosis of this entity.

Multidetector computed tomography evaluation of bladder lesions

Background

Urinary bladder tumors are the most common type of tumors detected in patients with gross hematuria. Multidetector computed tomography (MDCT) is an accurate method for detecting bladder lesions. This review aims to describe the features of MDCT and the possible values for distinguishing these lesions in the bladder.

Main body

In this review, we discuss the role of MDCT in the evaluation of patients with bladder cancer and describe a broad spectrum of bladder lesions, including malignant bladder lesions beyond bladder cancer, benign bladder lesions, and diffuse bladder wall thickening.

Short conclusion

Familiarity with the clinical presentations and imaging features of bladder lesions can lead to more accurate diagnosis and appropriate management.

Imaging features of juvenile xanthogranuloma

BACKGROUND

Juvenile xanthogranuloma is rare in children and there are limited data on its imaging features.

OBJECTIVE

To analyze the computed tomography (CT) and magnetic resonance imaging (MRI) features of juvenile xanthogranuloma in children.

MATERIALS AND METHODS

A retrospective review was performed of clinical and radiographic data of histologically confirmed juvenile xanthogranuloma between January 2009 and June 2020.

RESULTS

Fourteen children (4 girls, 10 boys; age range: 1 day to 13 years, mean age: 73 months) were included in the study: 4/14 had CT only, 5/14 had MRI only and 5/14 had CT and MRI. Sites of extracutaneous juvenile xanthogranuloma involvement included subcutaneous soft tissue (8/14), liver (2/14), lungs (2/14), kidney (2/14), nose (2/14), pancreas (1/14), central nervous system (1/14) and greater omentum (1/14), mainly manifested as single or multiple nodules or masses in different organs. On CT, the lesions mainly manifested as an iso-hypo density mass with mild or marked enhancement. On MRI, the lesions mainly manifested as slightly hyperintense on T1 and slightly hypointense on T2, with decreased diffusivity and homogeneous enhancement. Juvenile xanthogranuloma was not included in the imaging differential diagnosis in any case.

CONCLUSION

Juvenile xanthogranuloma mainly manifests as single or multiple nodules or masses in different organs. Slight hyperintensity on T1 and slight hypointensity on T2 with decreased diffusivity and homogeneous enhancement are relatively characteristic imaging findings of juvenile xanthogranuloma. Combined with its typical skin lesions and imaging features, radiologists should include juvenile xanthogranuloma in the differential diagnosis when confronted with similar cases.

"Another inchworm sign" on dynamic contrast-enhanced magnetic resonance imaging in pediatric patients with cystitis cystica and glandularis: Radiologic-pathologic correlation

Cystitis cystica and glandularis is a hyperproliferative disease of the urothelium, and may form a papillary or polypoid mass. Clinically, these mass lesions are often difficult to distinguish from malignant tumors. We present a pediatric patient of cystitis cystica and glandularis with a bladder mass and discuss dynamic contrast-enhanced magnetic resonance imaging (MRI) findings and histopathological profiles, which have not been previously explored in the literature. Dynamic contrast-enhanced MRI showed unique, superficial, strong enhancement that resembles an inchworm in appearance. The term "inchworm sign" is a characteristic finding on diffusion-weighted MRI, proposed as a criterion for T-staging in non-muscle-invasive bladder cancer. We would like to propose another "inchworm sign" on dynamic contrast-enhanced MRI as a new hallmark of cystitis cystica and glandularis, which may differentiate it from a malignant tumor.

Incidental findings on prostate MRI: a close look at the field of view in this anatomical region

Magnetic resonance imaging (MRI) has been widely used as an advanced imaging modality to detect prostate cancer and indicate suspicious areas to guide biopsy procedures. The increasing number of prostate examinations with MRI has provided an opportunity to detect incidental lesions, and some might be very significant to elucidate patient symptoms or occult neoplastic process in the early stages. These incidental lesions might be located in the prostate gland, adjacent tissues, or organs around the prostate gland or out of the genitourinary system. The field of view of prostate MRI includes not only the prostate gland but also other critical pelvic organs in this specific anatomical region. Some of these incidental lesions might cause the same symptoms as prostate cancer and might explain the symptoms of the patient, and some might indicate early cancer stages located outside the prostate. Reporting these lesions might be life-saving by initiating early disease treatment. Awareness of the predicted locations of congenital anomalies would also be beneficial for the radiologists to mention these incidental findings.

Radiologic Diagnosis and Staging of Bladder Cancer: An Update

Although cystoscopic biopsy is the standard of care for initial diagnosis and local staging of bladder cancer, radiologic imaging plays a major role in identifying local invasion, nodal status, distant metastasis, and posttreatment surveillance. Recent development of the Vesical Imaging-Reporting and Data System for interpretation of multiparametric magnetic resonance imaging of the bladder has expanded the role diagnostic imaging in the management of bladder cancer. This article reviews multimodality imaging appearances, staging, and differential diagnosis of bladder cancer.

Multiparametric MRI Evaluation of VI-RADS for Bladder Tumors Located at the Ureteral Orifice

Background The Vesical Imaging Reporting and Data System (VI-RADS) based on multiparametric MRI scans standardizes preoperative bladder cancer staging. However, limitations have been reported for VI-RADS, particularly for ureteral orifice tumors. Purpose To investigate the diagnostic performance and interobserver agreement of VI-RADS in evaluating muscle invasion for bladder tumors located at the ureteral orifice. Materials and Methods In this retrospective study, patients with histopathologically confirmed bladder cancer occurring at the ureteral orifice from January 2012 to November 2021 were analyzed. Two blinded radiologists independently scored multiparametric MRI scans according to VI-RADS. Interobserver agreement of the VI-RADS scores was evaluated with weighted κ analysis. Receiver operating characteristic curve analysis was used to evaluate the diagnostic performance of the VI-RADS scores in the prediction of muscle invasion. Results A total of 78 patients (mean age, 67 years ± 7 [SD]; age range, 46-90 years; 67 men) were included in the final analysis: 25 with non-muscle-invasive bladder cancer and 53 with muscle-invasive bladder cancer (MIBCa). At consensus reading, one (1%) case was scored as VI-RADS 1, 27 cases (35%) were scored as VI-RADS 2, six (8%) were scored as VI-RADS 3, 10 (13%) were scored as VI-RADS 4, and 34 (44%) were scored as VI-RADS 5. On comparison of the VI-RADS score with histopathologic findings, it was confirmed that the presence of muscle invasion was 0% (zero of one) for VI-RADS 1, 15% (four of 27) for VI-RADS 2, 83% (five of six) for VI-RADS 3, 100% (10 of 10) for VI-RADS 4, and 100% (34 of 34) for VI-RADS 5. The area under the receiver operating characteristic curve of VI-RADS in the detection of MIBCa was 0.96 (95% CI: 0.92, 1.00). Conclusion The Vesical Imaging Reporting and Data System could be used to accurately predict muscle invasion for bladder tumors occurring at the ureteral orifice. © RSNA, 2022 Online supplemental material is available for this article.

A rare case of urachal mucinous adenocarcinoma detected by 18F-FDG PET/CT and MRI

Urachal adenocarcinomas are rare cancers of the urinary bladder. Both CT and MRI are useful imaging modalities for the diagnosis and evaluation of urachal adenocarcinoma. Unlike CT or MR, there have been variable FDG PET findings with urachal tumours potentially due to considerable variation in their hypermetabolism. We present the case of a 24 year-old female patient who was diagnosed with urachal mucinous adenocarcinoma with characteristic features on CT and MRI which also exhibit moderately increased FDG avidity.

Mucoid-producing lesion following hip arthroplasty

A 54-year-old patient with a history of total hip arthroplasty (THA) presented with recurrent bladder infections, gross hematuria, and sediment in urine. The urinary complaints were unresponsive to transurethral resection and partial cystectomy. On further evaluation, a communicating fistulous tract was discovered between the site of hip arthroplasty, ischiorectal fossa, and bladder. Bladder involvement as a morbid delayed complication of total hip arthroplasty is an unusual finding, particularly in the form of a mucoid-producing lesion and vesicoacetabular fistula. Similarly unusual irritative urological symptoms unresponsive to treatment should prompt consideration of potential orthopedic hardware involvement.

Imaging of acute pelvic pain

Acute pelvic pain (APP) requires urgent medical evaluation and treatment. Differential diagnosis of APP is broad, including a variety of gynecologic and non-gynecologic/ urinary, gastrointestinal, vascular and other entities. Close anatomical and physiological relations of pelvic structures, together with similar clinical presentation of different disorders and overlapping of symptoms, especially in the emergency background, make the proper diagnosis of APP challenging. Imaging plays a crucial role in the fast and precise diagnosis of APP. Ultrasonography is the first-line imaging modality, often accompanied by CT, while MRI is utilized in specific cases, using short, tailored protocols. Recognizing the cause of APP in females is a challenging task, due to the wide spectrum of possible origin and overlap of their imaging features. Therefore, the radiologist has to be familiar with the possible causes of APP, and, relying on clinical presentation, together with laboratory findings, choose the best imaging strategy in order to establish a fast and accurate diagnosis.

A Case of Incidentally Detected Bladder Lipoma and a Review of the Literature

BACKGROUND

Lipomas are benign fatty tumors made of fat tissue. Bladder lipomas are extremely rare. For this reason, it is necessary to be aware of the imaging features when incidentally detected in imaging.

CASE REPORT

In the abdominal computed tomography (CT) performed as part of the follow-up examination of a 43-year-old patient, who had undergone surgery for adrenal adenoma five years earlier, a 14x9x8 mm smoothly marginated, ovoid-shaped, hypodense mass lesion with a homogeneous internal structure was detected in the anterior bladder wall. The pre-contrast density of the lesion was measured as -105 HU. The magnetic resonance imaging performed one year after the CT examination revealed a 14x9x8 intramural mass in the bladder wall, showing protrusion toward the lumen. The group was observed to be markedly hypointense on fat-suppressed T1 and T2-weighted images and considered consistent with a bladder lipoma.

DISCUSSION

Bladder lipomas are benign lesions that can vary in clinical presentations but usually cause hematuria. The differential diagnosis of bladder lipomas includes other mesenchymal rare benign tumors that can arise from the urinary bladder submucosal layer, including leiomyoma, hemangioma, plasmacytoma, fibroma, and neurofibroma, in imaging bladder lipomas present as homogeneous lesions containing macroscopic fat. Only the liposarcoma and pelvic lipomatosis could also show similar features. The less differentiated liposarcomas tend to present more heterogeneous enhancement, irregular-shaped margins, and infiltrative behavior. Also, appropriate multiplanar reconstructions may allow the radiologist to determine it is an extravesical pelvic lipomatosis.

CONCLUSION

Using CT and MRI, these lesions rich in adipose tissue can be distinguished from other lesions, and their diagnosis can be made to a great extent. However, a histopathological examination is required for a definitive diagnosis.

Imaging Manifestations of Genitourinary Tuberculosis

The genitourinary region is one of the most common sites of extrapulmonary tuberculosis (TB) involvement. The imaging features of genitourinary TB are protean and can mimic other entities, including malignancy, and pose a diagnostic dilemma. Hematogenous seeding and lymphatic spread of mycobacteria from pulmonary, tonsillar, and nodal TB are implicated in the pathogenesis of genitourinary TB. In addition, contiguous extension from the urinary tract and sexual transmission are described as sources of genital TB. Genitourinary TB can be indolent and results in nonspecific signs and symptoms; thus, imaging has a vital role in the working diagnosis for these cases. Classic uroradiologic signs of genitourinary TB are primarily described from the era of intravenous urography and conventional radiography. Now, CT, CT urography, MRI, and US are used in the diagnosis and management. Familiarity with the imaging features of genitourinary TB may help guide the diagnosis and, in turn, lead to timely management. US has a vital role in the evaluation of scrotal and female genital TB. MRI offers superior soft-tissue contrast resolution and excellent depiction of anatomic detail. The various imaging manifestations of genitourinary TB are highlighted. ^©RSNA, 2021.

Nephrogenic adenoma of the ureter in a teenager with history of leukemia

Nephrogenic adenomas represent a suspected metaplastic response of the uroepithelium to chronic inflammation and are typically associated with recurrent urinary tract infections, stones, prior radiation therapy and other irritative factors, more commonly seen in adults. Nephrogenic adenoma (also known as nephrogenic metaplasia) usually involves the bladder in adults and represents a rare lesion that can easily be misdiagnosed as a malignancy. We present the case of a 14-year-old male with prior history of acute lymphoblastic leukemia (ALL) who presented with a several month history of vague flank pain which increased in intensity, leading to an emergency department presentation with the only significant finding on exam being microhematuria. Subsequent imaging showed a tumor like replacement of the right ureter with proximal hydronephrosis, initially felt to represent recurrent leukemia. Pathology revealed the tumor like ureteral replacement to represent a nephrogenic adenoma, a benign entity which often responds to conservative management, though not previously reported in the ureter in pediatrics.

Imaging of Bladder Cancer: Standard Applications and Future Trends

The evolution in imaging has had an increasing role in the diagnosis, staging and follow up of bladder cancer. Conventional cystoscopy is crucial in the diagnosis of bladder cancer. However, a cystoscopic procedure cannot always depict carcinoma in situ (CIS) or differentiate benign from malignant tumors prior to biopsy. This review will discuss the standard application, novel imaging modalities and their additive role in patients with bladder cancer. Staging can be performed with CT, but distinguishing between T1 and T2 BCa (bladder cancer) cannot be assessed. MRI can distinguish muscle-invasive from non-muscle-invasive tumors with accurate local staging. Vesical Imaging-Reporting and Data System (VI-RADS) score is a new diagnostic modality used for the prediction of tumor aggressiveness and therapeutic response. Bone scintigraphy is recommended in patients with muscle-invasive BCa with suspected bony metastases. CT shows low sensitivity for nodal staging; however, PET (Positron Emission Tomography)/CT is superior and highly recommended for restaging and determining therapeutic effect. PET/MRI is a new imaging technique in bladder cancer imaging and its role is promising. Texture analysis has shown significant steps in discriminating low-grade from high-grade bladder cancer. Radiomics could be a reliable method for quantitative assessment of the muscle invasion of bladder cancer.

Eosinophilic cystitis mimicking bladder cancer-considerations on the management based upon a case report and a review of the literature

The hypereosinophilic syndrome (HES) is a rare disorder characterized by hypereosinophilia and infiltration of various organs with eosinophils. Eosinophilic cystitis (EC), mimicking bladder cancer clinically but also in ultrasound and in radiographic imaging, is one potential manifestation of the HES occurring in adults as well as in children. This case report describes the course of disease in a 57-year-old male presenting with severe gait disorders and symptoms of a low compliance bladder caused by a large retropubic tumor. After extensive urine and serologic examination and histologic confirmation of EC the patient was subjected to medical treatment with cetirizine and prednisolone for 5 weeks. While gait disorders rapidly resolved, micturition normalized only 10 months after initiation of therapy. Based upon this course the authors recommend patience and reluctance concerning radical surgical intervention in EC. Key Points • Eosinophilic cystitis is a rare condition with app. 200 cases reported, so far. • Etiology of eosinophilic cystitis is obscure, but allergies and parasitic infections may trigger the disease. • Genetic alterations (e.g., BRAF mutations) may predispose for the disease • Corticosteroids and antihistamines are the backbone of therapy and may be complemented by antibiotics and non-steroidal anti-inflammatory drugs in case of concomitant (underlying) infections. • As recovery can occur even after a long time, radical surgery should be restricted to highly selected cases.

CT and MRI in Urinary Tract Infections: A Spectrum of Different Imaging Findings

There are many acute and chronic infections affecting the urinary tract including bacterial, fungal and viral infections. Urinary tract infections (UTIs) can present in many different patterns with variable degrees of severity varying from asymptomatic and uncomplicated forms to life threatening complicated infections. Cross-sectional imaging techniques-including both computed tomography (CT) and magnetic resonance imaging (MRI)-have become very important tools not only for evaluation of UTIs, but also for detection of associated complications. Selection of either CT or MRI in the UTI evaluation depends on several factors such as the presence of contraindication, experience, cost and availability. CT and MRI help in early detection and management of UTIs that reduce the prevalence and severity of complications. In this article we will present the radiologic findings at CT and MRI in different types of upper and lower UTIs including acute pyelonephritis, intrarenal and perinephric abscesses, pyonephrosis, chronic pyelonephritis, emphysematous UTIs, xanthogranulomatous pyelonephritis, tuberculosis (TB), bilharziasis, fungal infection, corynebacterium infection, ureteritis, cystitis, prostatitis, prostatic abscess and urethritis.

Urinary bladder lipoma: an illustrative case

Urinary bladder lipomas are rare neoplasms. Therefore, very few of them have been reported in the literature. We present a case that illustrates the typical features that allow radiologists to diagnose this entity: a solid lesion that arises from the urinary bladder wall, showing an endophytic growth and homogeneous hypoattenuation. After its surgical resection, the diagnosis was confirmed by anatomo-pathological analysis. In the discussion we describe other neoplasms that should also be considered when a submucosal bladder neoplasm is detected on computed tomography or other imaging techniques.

Quantitative Analysis of Enhanced Computed Tomography in Differentiating Cystitis Glandularis and Bladder Cancer

Objective

This study was performed to assess the value of quantitative analysis of enhanced computed tomography (CT) values in the differential diagnosis of bladder cancer and cystitis glandularis (CG).

Methods

Eighty patients with bladder masses (39 with CG and 41 with bladder cancer) who underwent enhanced CT were retrospectively reviewed. The CT enhancement values of the lesion and normal bladder wall in the arterial phase, venous phase, and delayed phase were measured. The relative enhancement CT values (relative enhancement CT value = enhancement CT value of lesion - enhancement CT value of normal bladder) in the arterial phase, venous phase, and delayed phase were also calculated. The pathological results were used as the gold standard, and the area under the curve (AUC), sensitivity, and specificity were calculated for the six groups of quantitative indicators (enhanced CT values and relative enhanced CT values of CG and bladder cancer in the arterial, venous, and delayed phases). We performed the leave-group-out cross-validation method to validate the accuracy, AUC, sensitivity, and specificity. The differences in accuracy, AUC, sensitivity, and specificity among the six groups of quantitative indicators were compared by the t-test.

Results

In a combined analysis of the AUC, sensitivity, and specificity performance, the best indicator was the arterial-phase relative enhancement CT value with a cut-off of 25.85 HU (AUC, 0.966; sensitivity, 95.1%; specificity, 92.3%). We used the 100-times leave-group-out cross-validation method to validate the accuracy, AUC, sensitivity, and specificity. Arterial-phase relative enhancement CT values showed the highest AUC and accuracy among the six groups, with statistical significance (P < 0.05).

Conclusion

Quantitative analysis of enhanced CT is of great clinical value in the differential diagnosis of CG and bladder cancer.

Imaging findings of infectious and inflammatory diseases of the urinary system mimicking neoplastic diseases

Neoplastic diseases affecting the urinary organs are common, and diagnosis by imaging is usually straightforward. However, infectious/inflammatory processes also commonly affect these organs and can be mistaken for a neoplasm. Familiarity with these potential mimickers and awareness of their imaging presentations are key for correct diagnosis. We present the imaging findings of non-neoplastic infectious/inflammatory diseases that can mimic a neoplastic process.

Radiographic and Endoscopic Features of Pancreaticoduodenal Malakoplakia

Malakoplakia is a rare, granulomatous disorder that is typically triggered by infections in immunocompromised patients. Although it most commonly affects the urinary tract, cases may occasionally occur in the gastrointestinal tract. There are case reports of malakoplakia of the pancreas with associated pathologic description, but none with detailed imaging and endoscopic findings. In addition, description of magnetic resonance imaging characteristics of mass-forming malakoplakia in the literature is sparse. We present a case of pancreaticoduodenal malakoplakia in an immunocompromised patient, including detailed description of magnetic resonance imaging, computed tomography, and endoscopic findings with radiology-pathology correlation. Classic pathologic features of malakoplakia (eg, hypercellularity, inflammation, and mineralization of Michaelis-Gutmann bodies) lead to specific features on imaging, such as marked diffusion restriction, heterogeneous enhancement, calcification, and increased attenuation on nonenhanced computed tomography. These features may help differentiate malakoplakia from other more common lesions that occur in this location, especially if present in an immunocompromised patient.

Imaging Features of Urachal Cancer: A Case Report

Urachal adenocarcinoma originates from the space of Retzius. It is a rare but aggressive neoplasm. Typical imaging findings of urachal cancer are difficult to find; this report provides an ultrasonographic (US) and computed tomographic (CT) description of the above. We present a case of a 45-year-old male patient presenting with painless hematuria of 1 week's duration and display the US and CT images. Imaging shows: (1) a solid, ill-defined, irregularly shaped mass invading the bladder wall located between the dome of the bladder and the abdominal wall, and which underwent significant enhancement; (2) hypo-echoic, heterogeneous echopattern with some calcifications and (3) patchy and short-line blood flow signals within the mass. Final histopathology confirmed urachal adenocarcinoma.

Advanced urothelial cancer: a radiology update

The recent genomic characterization of urothelial carcinoma by the Cancer Genome Atlas Project, made possible by the introduction of high throughput, reduced cost, and sequence analysis, has shed new insights on the biology of advanced disease. In addition, studies on imaging of advanced urothelial carcinoma have widened the knowledge on disease presentation and on pattern of metastatic spread and their correlation with the underlying biology of urothelial carcinoma. The wide range of treatments for advanced urothelial cancer, including combined chemotherapy regimens and immune checkpoint inhibitors, each result in treatment class-specific patterns of response and adverse events. Results of studies point to the need for a reliable biomarker, perhaps with imaging, that predicts prognosis and treatment response to systemic treatment, and can be used to select the most effective treatment while minimizing toxicity. This review of advanced urothelial cancer introduces the latest advances in genetic profiling, the current role of imaging, the radiographic appearance of treatment response and their toxicities, and details potential future areas of imaging research.

Imaging of urachal anomalies

Urachal anomalies are classified into four types depending on the level of persistence of the embryonic urachal remnants between the urinary bladder and the umbilicus: patent urachus, umbilical-urachal sinus, urachal cyst, and vesico-urachal diverticulum. Due to the increasing use of cross-sectional imaging, urachal anomalies are frequently detected as incidental findings. Imaging plays a pivotal role in the initial diagnosis, evaluation of complications, treatment follow-up, and long-term surveillance of patients with urachal anomalies. Different urachal anomalies demonstrate characteristic imaging features that aid in a timely diagnosis and guide treatment. A patent urachus is visualized as an elongated tubular structure between the umbilicus and the urinary bladder. While umbilical-urachal sinus appears as focal dilatation at the umbilical end of the urachal remnant, the vesico-urachal diverticulum presents as a focal outpouching of the urinary bladder at anterosuperior aspect. Urachal cysts are identified as midline fluid-filled sacs most frequently located near the dome of the urinary bladder. Untreated urachal anomalies could progress into potential complications, including infection and malignancy. Knowledge regarding imaging features of urachal anomalies helps in timely diagnosis, treatment, follow-up, and early detection of complications.

Bladder cancer and its mimics: a sonographic pictorial review with CT/MR and histologic correlation

Bladder cancer is the most common cancer of the urinary system and often presents with hematuria. Despite its relatively high incidence, bladder cancer is often under-recognized sonographically. Moreover, even when bladder abnormalities are identified, numerous other entities may mimic the appearance of bladder cancer. Given the incidence and prevalence of bladder cancer, it is important to recognize its variable appearance sonographically and distinguish it from its common mimics. We review the sonographic appearance of bladder cancer and its mimics, providing correlative CT/MR imaging as well as pathology. We stress the importance and advantage of ultrasound as a dynamic imaging modality, with the ability to optimize distinguishing bladder cancer from similar-appearing entities.

Sonographic Evaluation of Genitourinary Inflammatory Pseudotumors and Its Mimics

Inflammatory pseudotumor is a relatively rare, nonneoplastic lesion composed of inflammatory cells and myofibroblastic spindle cells that can be identified on sonographic evaluation of the genitourinary system. These lesions are thought to be an inflammatory response to insults such as surgery, trauma, infection, or malignancy. Such lesions need to be distinguished from true neoplasms and other benign lesions, including inflammatory responses and infectious processes. Identification of inflammatory pseudotumors and its mimics is important for radiologists to guide patient treatment and follow-up. This pictorial essay presents sonographic features of inflammatory pseudotumors of the genitourinary tract and its mimics with cross-sectional imaging and histopathology, where available.

Imaging of non-traumatic urinary bladder emergencies

Non-traumatic urinary bladder emergencies are rare but critical diagnoses to make in an emergency setting. Acute urinary bladder pathologies require an accurate and timely diagnosis to ensure a favorable clinical outcome. Multidetector computed tomography (CT) is the imaging modality of choice for acute and emergent conditions affecting the urinary bladder. MRI is helpful as a problem-solving modality due to better soft tissue characterization and higher in-plane resolution. The purpose of this article is to illustrate the spectrum of urinary bladder emergencies, review the imaging findings, and briefly describe the role of imaging in the evaluation of such patients. Although there are a few cases of bladder emergencies been reported separately, the literature summarizing the spectrum is lacking. The objective of this article is to review the imaging of acute emergencies involving urinary bladder that will help us to think beyond non-specific conclusion in an emergency setting. For the sake of focused discussion, traumatic bladder emergencies will be excluded in this review. In the era of highly image reliant clinical practice, radiologists must be familiar with the diagnostic strategy to approach these entities.

Transurethral resection of a large bladder hemangioma of mixed histological composition: a case report

Hemangioma is a rare benign vascular tumor of the bladder, which occurs mainly in children. It has no specific clinical symptoms but can result in severe and fatal complications as well as relapse. In the current clinical observation, a 35-year-old patient had a large solid tumor of the bladder spreading into the muscular layer. In histological and immunohistochemical analyses, verified hemangioma consisted of capillary, cavernous and arterio-venous components. The patient underwent transurethral resection of the bladder using computer chromoendoscopy. It is the first to the best of our knowledge complete transurethral removal of 3 cm in diameter bladder hemangioma.

Isolation and multipotential differentiation of mesenchymal stromal cell‑like progenitor cells from human bladder

Various types of mesenchymal stromal cells (MSCs) have been used in urological tissue engineering but to date the existence of MSCs has not been reported in the human bladder. The present study provided evidence that a small number of MSC‑like cells exist in the human bladder and designated this class of cells 'human bladder‑derived MSC‑like cells' (hBSCs). It was demonstrated that hBSCs can be cultured to yield a large population. These hBSCs expressed the surface markers of MSCs and exhibited the capacity for osteogenic, adipogenic and chondrogenic differentiation. On induction with appropriate media in vitro, hBSCs could differentiate into bladder‑associated cell types, including urothelial, endothelial and smooth muscle cell‑like lineages. In addition, the average telomerase activity of adult hBSCs was higher compared with adult human bone marrow‑derived MSCs, but lower than that of human umbilical cord Wharton's jelly‑derived MSCs. These findings may inspire future studies on the role of hBSCs in urological tissue engineering applications and in other fields.

Infectious and Inflammatory Diseases of the Urinary Tract: Role of MR Imaging

Urinary tract infection (UTI) is among the most common of bacterial infections. Imaging studies are only required in cases of complicated UTIs. Ultrasound remains the first-line imaging method; however, CT is the gold standard for evaluation of UTIs. MR imaging's improved contrast resolution and absence of ionizing radiation may recommend its use for assessment of lower UTIs. Furthermore, MR imaging performs with diagnostic accuracy at least similar to CT in complicated UTIs, except for the identification of calculi and emphysematous pyelonephritis. In this article, the role of MR imaging for the evaluation of infectious and inflammatory disease processes of the urinary tract is reviewed.

Normal reference values for bladder wall thickness on CT in a healthy population

PURPOSE

To determine normal bladder wall thickness on CT in patients without bladder disease.

MATERIALS AND METHODS

Four hundred and nineteen patients presenting for trauma with normal CTs of the abdomen and pelvis were included in our retrospective study. Bladder wall thickness was assessed, and bladder volume was measured using both the ellipsoid formula and an automated technique. Patient age, gender, and body mass index were recorded. Linear regression models were created to account for bladder volume, age, gender, and body mass index, and the multiple correlation coefficient with bladder wall thickness was computed. Bladder volume and bladder wall thickness were log-transformed to achieve approximate normality and homogeneity of variance. Variables that did not contribute substantively to the model were excluded, and a parsimonious model was created and the multiple correlation coefficient was calculated. Expected bladder wall thickness was estimated for different bladder volumes, and 1.96 standard deviation above expected provided the upper limit of normal on the log scale.

RESULTS

Age, gender, and bladder volume were associated with bladder wall thickness (p = 0.049, 0.024, and < 0.001, respectively). The linear regression model had an R² of 0.52. Age and gender were negligible in contribution to the model, and a parsimonious model using only volume was created for both the ellipsoid and automated volumes (R² = 0.52 and 0.51, respectively).

CONCLUSION

Bladder wall thickness correlates with bladder wall volume. The study provides reference bladder wall thicknesses on CT utilizing both the ellipsoid formula and automated bladder volumes.

Multiparametric Magnetic Resonance Imaging for Bladder Cancer: Development of VI-RADS (Vesical Imaging-Reporting And Data System)

CONTEXT

Management of bladder cancer (BC) is primarily driven by stage, grade, and biological potential. Knowledge of each is derived using clinical, histopathological, and radiological investigations. This multimodal approach reduces the risk of error from one particular test, but may present a staging dilemma when results conflict. Multiparametric magnetic resonance imaging (mpMRI) may improve patient care through imaging of the bladder with better resolution of the tissue planes than computed tomography and without radiation exposure.

OBJECTIVE

To define a standardized approach to imaging and reporting mpMRI for BC, by developing a VI-RADS score.

EVIDENCE ACQUISITION

We created VI-RADS (Vesical Imaging-Reporting And Data System) through consensus using existing literature.

EVIDENCE SYNTHESIS

We describe standard imaging protocols and reporting criteria (including size, location, multiplicity, and morphology) for bladder mpMRI. We propose a five-point VI-RADS score, derived using T2-weighted MRI, diffusion-weighted imaging, and dynamic contrast enhancement, which suggests the risks of muscle invasion. We include sample images used to understand VI-RADS.

CONCLUSIONS

We hope that VI-RADS will standardize reporting, facilitate comparisons between patients, and in future years, will be tested and refined if necessary. While we do not advocate mpMRI for all patients with BC, this imaging may compliment pathology or reduce radiation-based imaging. Bladder mpMRI may be most useful in patients with non-muscle-invasive cancers, in expediting radical treatment or for determining response to bladder-sparing approaches.

PATIENT SUMMARY

Magnetic resonance imaging (MRI) scans for bladder cancer are becoming more common and may provide accurate information that helps improve patient care. Here, we describe a standardized reporting criterion for bladder MRI. This should improve communication between doctors and allow better comparisons between patients.

Complete reversal of the clinical symptoms and image morphology of ketamine cystitis after intravesical hyaluronic acid instillation: A case report

RATIONALE

Ketamine abuse is an emerging issue in many countries, and ketamine cystitis (KC) is a growing disease which more and more urologists may encounter with. There was no gold standard diagnostic criteria of ketamine cystits established yet, but well-accepted with the positive substance abuse history and clinical symptoms. The clinical presentation of ketamine cystitis varies and may mimic those presented in interstitial cystitis (IC), such as voiding frequency, urgency with urge incontinence, dysuria, nocturia, burning sensation during urination, post urination pain, painful hematuria, and small bladder capacity, but there are still differences that KC presented with more urgency, hematuria, pyuria and upper urinary tract involvement such as ureteral stenosis, vesico-ureteric reflux, hydronephrosis and renal function impairment.

PATIENT CONCERNS

We presented an interesting case with a 36-year-old man who's symptoms mimic acute prostatitis but there was no positive pathogen been cultured. The computed tomography (CT) findings revealed asymmetrical bladder wall thickening, which misleading us to the impression of bladder cancer. After the cystoscopy with bladder biopsy, the pathology revealed severe inflammation without malignancy. After that, we prescribed anticholinergic agent, beta-3 agonist and nonsteroidal anti-inflammatory drug (NSAID) for him, but in vain.

DIAGNOSES

Erosive cystitis with prominent infiltration by eosinophils, lymphocytes, neutrophils and plasma cells.

INTERVENTIONS

Then we introduced hyaluronic acid (HA) instillation, once a week for total 10 times.

OUTCOMES

After the treatment, his urgency, frequency, nocturia improved and his bladder capacity increased from less than 100ml to 350mL per urination. The following magnetic resonance imaging (MRI) and bladder biopsy result revealed complete reversal.

LESSONS

To our literature review, this is the first case of ketamine cystitis presented with asymmetrical bladder wall thickening, which may be considered as an irreversible change, but turns out complete reversal of the clinical symptoms and image morphology after merely intravesical hyaluronic acid instillation.

Computed Tomography and Magnetic Resonance Imaging Findings of Inflammatory Pseudotumors in the Abdomen and Pelvis: Current Concepts and Pictorial Review

The group of inflammatory pseudotumors (IPTs) encompasses a variety of rare neoplastic and nonneoplastic entities described to occur in almost every location in the body and whose clinical features and aggressive imaging findings (varying from infiltrative to mass-forming lesions), frequently mimic those of malignant tumors. The radiologic features of IPTs are variable and nonspecific, the imaging findings depending on the body location and involved organ. Abdominopelvic IPTs are rare and the purposes of this review, therefore, are to familiarize the radiologist with the wide spectrum of computed tomography and magnetic resonance imaging findings of IPTs in various locations throughout the abdomen and pelvis, discussing the imaging features that allow consideration of IPTs in the differential diagnosis of soft-tissue masses within the pertinent clinical setting. Radiologists should be aware of this group of entities, as a preoperative histopathologic diagnosis upon radiological suspicion may help to differentiate IPTs from malignancy and to allow the most appropriate clinical work-up for these patients.