Pediatric renal masses: Wilms tumor and beyond

Renal Lymphoma: Primary or First Manifestation of Aggressive Pediatric B-cell Lymphoma

Renal lymphoma is an uncommon renal tumor in children. Unlike renal lymphomas presenting as bilateral disease and renal failure, we report a boy who presented with unilateral renal involvement. After initial nephrectomy, he achieved remission with multiagent chemotherapy but relapsed systemically within 3 months. He was initiated on salvage chemotherapy with autologous bone marrow transplant. Even though the initial manifestation was localized lymphoma eventually, it turned out to be a systemic disease. He succumbed to disease at 14 months from diagnosis.

Peritoneal Malignancy in Children: A Pictorial Review

Peritoneal malignancies are a rare occurrence in children, often metastatic and rarely originating primarily in the peritoneum. The imaging findings of these entities in the pediatric age have not been recently reviewed or they have been previously described or depicted mostly as part of articles discussing each entity separately. This is a review of the most relevant peritoneal malignancies in childhood emphasizing imaging features. Knowledge of these appearances may facilitate diagnosis and staging of these neoplasms.

Ossifying renal tumor of infancy (ORIT): The clinicopathological and cytogenetic feature of two cases and literature review

Ossifying renal tumor of infancy (ORTI) is a rare benign pediatric renal tumor, which has typical clinical and pathological features. In this article, the histological features, immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) assay of two cases of ORTI were performed and the literatures were reviewed. Both of the patients presented to hospital with painless gross hematuria without other symptoms. One is 6 months old male, another is 5-month-old. After several diagnostic procedures, they underwent surgery and the histological diagnosis of ORTI was finally made. Grossly, the tumor had a nodular or irregular appearance, often partially calcified and located in the renal pelvis and calyces. The cut surface of this mass was grey-white, solid and firm. Histologically, the tumor was composed of three major histologic components: osteoblast-like cells, spindle cells, and an osteoid core. Immunohistochemistry staining revealed that osteoblast-like cells were positive for EMA, Vimentin and STAB2. Spindle cells were strongly immunoreactive for Vimentin, WT-1 and focally positive for SMA, but were negative for CK, PAX8 and PAX2. The FISH studies with CEP4 probe on interphase nuclei from the two ORTIs, revealed trisomy 4 were 8.97% (case 1) and 12.23% (case 2). Our study showed that clonal trisomy 4 may be considered as a cytogenetic feature of ORTI, which makes it distinct from other pediatric renal tumor.

Role of Computed Tomography in Pediatric Abdominal Conditions

In the pediatric patient, computed tomography (CT) scan as an imaging modality for evaluation of the abdomen is to be used judiciously. The use of correct scanning protocols, single phase scanning, scanning only when required are key factors to minimize radiation doses to the child, while providing diagnostic quality. CT is the preferred modality in the evaluation of trauma, to assess extent of solid organ or bowel injury. It is also useful in several inflammatory conditions such as inflammatory bowel diseases and acute pancreatitis. CT also has an important role in evaluating intra-abdominal tumors, although magnetic resonance imaging (MRI) can be used as an alternative to CT.

[Clear cell sarcoma of kidney in children]

Clear cell sarcoma of the kidney (CCSK) is a rare tumor that is diagnosed most often in children between 2- and 4-years-old of age. Usually, patients with CCSK are treated in international study for intrarenal tumors, preferentially Wilms tumor, according to bad histopronostic group. The purpose of this paper is to review the most important features in 2015 about epidemiology, radiology, anatomopathology and genetic of CCSK, and above all a synthesis about successive treatment strategies with their results. Second most common pediatric renal tumor in children less than 5-years-old, its prognosis has improved dramatically in recent years with the use of anthracyclines.

The spectrum of nephrocutaneous diseases and associations: Genetic causes of nephrocutaneous disease

There are a significant number of diseases and treatment considerations of considerable importance relating to the skin and renal systems. This emphasizes the need for dermatologists in practice or in clinical training to be aware of these associations. Part I of this 2-part continuing medical education article reviews the genetic syndromes with both renal and cutaneous involvement that are most important for the dermatologist to be able to identify, manage, and appropriately refer to nephrology colleagues. Part II reviews the inflammatory syndromes with relevant renal manifestations and therapeutic agents commonly used by dermatologists that have drug-induced effects on or require close consideration of renal function. In addition, we will likewise review therapeutic agents commonly used by nephrologists that have drug-induced effects on the skin that dermatologists are likely to encounter in clinical practice. In both parts of this continuing medical education article, we discuss diagnosis, management, and appropriate referral to our nephrology colleagues in the context of each nephrocutaneous association. There are a significant number of dermatoses associated with renal abnormalities and disease, emphasizing the need for dermatologists to be keenly aware of their presence in order to avoid overlooking important skin conditions with potentially devastating renal complications. This review discusses important nephrocutaneous disease associations with recommendations for the appropriate urgency of referral to nephrology colleagues for diagnosis, surveillance, and early management of potential renal sequelae.

Whole transcriptome sequencing identifies BCOR internal tandem duplication as a common feature of clear cell sarcoma of the kidney

PURPOSE

Clear cell sarcoma of the kidney (CCSK) is a rare pediatric renal tumor that is frequently difficult to distinguish among other childhood renal tumors due to its histological heterogeneity. This work evaluates genetic abnormalities carried by a series of CCSK samples by whole transcriptome sequencing (WTS), to identify molecular biomarkers that could improve the diagnostic process.

METHODS

WTS was performed on tumor RNA from 8 patients with CCSK. Bioinformatic analysis, with implementation of a pipeline for detection of intragenic rearrangements, was executed. Sanger sequencing and gene expression were evaluated to validate BCOR internal tandem duplication (ITD).

RESULTS

WTS did not identify any shared SNVs, Ins/Del or fusion event. Conversely, analysis of intragenic rearrangements enabled the detection of a breakpoint within BCOR transcript recurrent in all samples. Three different in-frame ITD in exon15 of BCOR, were detected. The presence of the ITD was confirmed on tumor DNA and cDNA, and resulted in overexpression of BCOR.

CONCLUSIONS

WTS coupled with specific bioinformatic analysis is able to detect rare genetic events, as intragenic rearrangements. ITD in the last exon of BCOR is recurrent in all CCSK samples analyzed, representing a valuable molecular marker to improve diagnosis of this rare childhood renal tumor.

[Radiological evaluation of congenital tumors]

In this article, we consider tumors that are diagnosed during pregnancy or in the first three months of life. This is a heterogeneous group of neoplasms with special biological and epidemiological characteristics that differentiate them from tumors arising in children or adults. In the last two decades, the prenatal detection of congenital tumors has increased due to the generalized use of prenatal sonographic screening. Advances in imaging techniques, especially in fetal magnetic resonance imaging, have enabled improvements in the diagnosis, follow-up, clinical management, and perinatal treatment of these tumors. This image-based review of the most common congenital tumors describes their histologic types, locations, and characteristics on the different imaging techniques used.

A rare case of bilateral cystic partially differentiated nephroblastoma recurring as bilateral cystic Wilms tumour

Childhood cystic partially differentiated nephroblastoma (CPDN) is an uncommon renal neoplasm. Bilateral CPDN or CPDN co-existing with a cystic nephroma/Wilms tumour is extremely rare. Treatment of CPDN is by complete surgical excision. Although local recurrences are uncommon, distant metastases have not been described. We present a case of bilateral CPDN that, after complete excision, recurred as bilateral cystic Wilms tumour. To the best of our knowledge, this is the first reported case in the literature where a bilateral CPDN has recurred as bilateral Wilms tumour.

Neuroblastoma and nephroblastoma: a radiological review

Neuroblastoma (NBL) is the most common extra-cranial tumour in childhood. It can present as an abdominal mass, but is usually metastatic at diagnosis so the symptomatology can be varied. Nephroblastoma, also more commonly known as a Wilms tumour, is the commonest renal tumour in childhood and more typically presents as abdominal pathology with few constitutional symptoms, although rarely haematuria can be a presenting feature. The pathophysiology and clinical aspects of both tumours including associated risk factors and pathologies are discussed. Oncogenetics and chromosomal abnormalities are increasingly recognised as important prognostic indicators and their impact on initial management is considered. Imaging plays a pivotal role in terms of diagnosis and recent imaging advances mean that radiology has an increasingly crucial role in the management pathway. The use of image defined risk factors in neuroblastoma has begun to dramatically change how this tumour is characterised pre-operatively. The National Wilms Tumour Study Group have comprehensively staged Wilms tumours and this is reviewed as it impacts significantly on management. The use of contrast-enhanced MRI and diffusion-weighted sequences have further served to augment the information available to the clinical team during initial assessment of both neuroblastomas and Wilms tumours. The differences in management strategies are outlined. This paper therefore aims to provide a comprehensive update on these two common paediatric tumours with a particular emphasis on the current crucial role played by imaging.

New insights into glomerular parietal epithelial cell activation and its signaling pathways in glomerular diseases

The glomerular parietal epithelial cells (PECs) have aroused an increasing attention recently. The proliferation of PECs is the main feature of crescentic glomerulonephritis; besides that, in the past decade, PEC activation has been identified in several types of noninflammatory glomerulonephropathies, such as focal segmental glomerulosclerosis, diabetic glomerulopathy, and membranous nephropathy. The pathogenesis of PEC activation is poorly understood; however, a few studies delicately elucidate the potential mechanisms and signaling pathways implicated in these processes. In this review we will focus on the latest observations and concepts about PEC activation in glomerular diseases and the newest identified signaling pathways in PEC activation.

An approach to renal masses in pediatrics

Renal masses in children may be discovered during routine clinical examination or incidentally during the course of diagnostic or therapeutic procedures for other causes. Renal cancers are rare in the pediatric population and include a spectrum of pathologies that may challenge the clinician in choosing the optimal treatment. Correct identification of the lesion may be difficult, and the appropriate surgical procedure is paramount for lesions suspected to be malignant. The purpose of this article is to provide a comprehensive overview regarding the spectrum of renal tumors in the pediatric population, both benign and malignant, and their surgical management.

Blunt renal trauma in children with pre-existing renal abnormalities

The kidneys are the most commonly injured genitourinary organ in children following blunt abdominal trauma. Though the retroperitoneal location affords the kidneys some protection from the forces experienced in blunt abdominal trauma, the kidneys are at greater risk of injury when a disease process exposes them from their normal shielded location. In such cases, the injuries may appear to be disproportionate in relation to the severity of the trauma history, confusing the imaging findings. Recognition of both the underlying disease process as well as the manifestations of acute trauma is important; therefore, we present a pictorial essay of traumatized kidneys in children with pre-existing renal abnormalities.

Intrarenal neuroblastoma with pulmonary metastases mimicking a Wilms tumor

Primary intrarenal neuroblastoma is extremely rare and is a mimic of Wilms tumor. We present a case of a renal mass in a 14month old male with lung metastases at the initial presentation. This was thought to represent a Wilms tumor. Histology of a biopsied lung nodule revealed neuroblastoma.

Clear cell sarcoma of the kidney: patients' characteristics and improved outcome in developing countries

BACKGROUND

Clear cell sarcoma of the kidney (CCSK) is a rare and aggressive tumor accounting for 5% of pediatric renal tumors with an incidence of 20 patients per year in the USA. It is bone metastasizing with poor prognosis. Our aim was to show characteristics of patients in relation to improved outcome in one of the developing countries.

PROCEDURE

We included all patients diagnosed as CCSK in the period between July 2007 and March 2012 at Children's Cancer Hospital, Egypt. Patients' demographics, clinical presentation, pathology, and management were reviewed. Follow up was continued until April 2013.

RESULTS

Twenty-five patients were identified in the defined time interval, accounting for 7% all renal tumors diagnosed at the hospital. Mean age was 36 months. Abdominal swelling and hematuria were the most common presentations. Stages I, II, III, IV, and V represented 9 (36%), 3 (12%), 8 (32%), 3 (12%), and 2 (8%), respectively. Twenty-four patients had radical nephrectomy either upfront or after neo-adjuvant chemotherapy. Surgery was followed by adjuvant chemotherapy. Abdominal radiotherapy was given for local stages II and III. Twenty-two patients reached complete remission, while one patient had stationary disease and two patients died due to progression and relapse. Overall survival was 88.5% and event-free survival was 87.8% at 45 months.

CONCLUSION

Although previous studies indicate poor prognosis of CCSK, our experience shows that those patients can be treated using extensive chemotherapy combined with proper local control.

Incidental renal mass found on focused assessment with sonography in trauma

We present the case of a 9-year-old female who presented after minor blunt abdominal trauma during a sporting event. On focused assessment with sonography for trauma, she was found to have an incidental renal mass, which was ultimately diagnosed as a renal cell carcinoma. In this report, we focus on the use of bedside ultrasound as a screening test and the management of incidental findings.

Inferior vena cava aneurysm in an infant presenting with a renal mass

Aneurysm of the inferior vena cava is a rare finding in the pediatric population. We report the case of a 5-month-old infant presenting with anemia, hypertension, and dehydration in the emergency room. A renal mass was found with ultrasound and MRI and a renal tumor was first considered. Histopathologic review of the surgical specimen led to the diagnosis of aneurysmal dilatation of the vena cava.

CT findings of intrarenal yolk sac tumor with tumor thrombus extending into the inferior vena cava: a case report

Yolk sac tumor (YST) is a rare germ cell neoplasm of childhood that usually arises from the testis or ovary. The rare cases of YST in various extragonadal locations have been reported, but the primary intrarenal YST is even more uncommon. Here, we report a case of a primary intrarenal YST with tumor thrombus of the inferior vena cava and left renal vein in a 2-year-old boy, with an emphasis on the CT features. To our knowledge, this is the first reported case of an intrarenal YST with intravascular involvement.

Update on pediatric leukemia and lymphoma imaging

Together, leukemia and lymphoma account for half of all childhood malignancies. Leukemia and lymphoma arise from similar cell lines and can have overlapping imaging features; however, the clinical presentation, imaging strategies, and treatment protocols can vary substantially based on the specific subtype. Although imaging does not play a central role in staging or monitoring disease in childhood leukemia, findings on imaging may be the first indication of the diagnosis. Advanced imaging, especially positron emission tomography/computed tomography, has moved to the forefront of staging and treatment response evaluation in Hodgkin's disease and non-Hodgkin's lymphoma. Imaging also plays a key role in evaluating the myriad of treatment complications that are commonly seen with chemotherapy and associated neutropenia. Future efforts will be largely focused on decreasing radiation exposure to these children, utilizing reduced or radiation-free modalities, such as positron emission tomography/magnetic resonance and diffusion-weighted whole-body imaging with background suppression, as well as refining surveillance imaging strategies. The purpose of this article is to briefly review the classification of pediatric leukemia and lymphoma, illustrate common imaging findings at presentation throughout the body, describe staging and therapeutic response evaluation, and show a spectrum of commonly encountered complications of treatment.

The current state of imaging pediatric hemoglobinopathies

The hemoglobinopathies are a group of genetic disorders with a broad spectrum of clinical manifestations and radiologic findings. The imaging of pediatric hemoglobinopathies, which is influenced by concomitant hemosiderosis and the sequela of chelation therapy, has evolved over the years along with ever-improving technology. This article reviews and illustrates the most common radiographic and cross-sectional imaging findings of the 2 best known and clinically relevant hemoglobinopathies in pediatric patients, sickle cell disease and β-thalassemia.

Ossifying renal tumor of infancy: findings at ultrasound, CT and MRI

A 4-month-old boy presented with persistent gross hematuria. At ultrasonography, a 3.5-cm echogenic mass with posterior shadowing and tumor vascularity was detected within the right renal pelvis. Precontrast CT showed a slightly hyperattenuating mass in the renal pelvis. At MRI the mass was heterogeneously hypointense on T2-weighted images and isointense on T1-weighted images. Contrast-enhanced CT and MRI both revealed peripheral enhancement of the mass. A histological diagnosis of ossifying renal tumor of infancy was made after open pyelostomy and tumor enucleation. We suggest that ossifying renal tumor of infancy should be considered when a mass with posterior acoustic shadowing and tumor vascularity on US, hyperattenuation on precontrast CT and hypointensity on T2-weighted MRI is seen within the renal pelvis of an infant with hematuria.

Alveolar soft part sarcoma arising from the kidney: imaging and clinical features

Alveolar soft part sarcoma (ASPS) is an extremely rare malignant soft tissue sarcoma primarily affecting young patients. It usually occurs in the lower extremities, although it can occur in soft tissue anywhere in the body. However, to our knowledge, there has been no case of primary ASPS originating from the kidney in the literature. We herein present the imaging and clinical features of an ASPS which occurred in a 16-year-old male presented as a palpable mass in the left side of the abdomen.

Case report and literature review of a rare diagnosis of ossifying renal tumour of infancy

One must entertain a broad differential diagnosis for infants presenting with gross hematuria. Initial workup includes urine analysis, serum laboratory values and abdominal ultrasound. We describe an infant presenting with gross hematuria found to have a calcified renal mass upon initial ultrasound and subsequent computed tomography scan. We considered a differential diagnosis of, but not exclusive to, staghorn calculi, nephroblastoma, Wilms' tumour, mesoblastic nephroma and ossifying renal tumour of infancy (ORTI). A nephrectomy was performed, and the pathology report identified the calcified mass as an ORTI.

WARM N COLD: malignant and benign renal tumors in children

Although Wilms tumor is the most common renal malignancy in children, the differential diagnosis is extensive and includes both malignant and benign disorders. We present a simple mnemonic-WARM N COLD, to aid in remembering these diverse tumors. Imaging clues including age of the patient, associated disease or syndrome as well as salient imaging characteristics such as bilaterality, and type or presence of metastasis are also presented and can help differentiate between these renal tumors of childhood.

Antenatally detected solid tumour of kidney

Congenital renal tumours are rare and usually benign. Polyhydramnios is the most common mode of presentation. Although most cases have been diagnosed postnatally, with advances in imaging technology, an increasing number of cases are being detected on antenatal scans. We describe a case of solid tumour of kidney detected in the second trimester of pregnancy and managed by surgery in the postnatal period.

Pediatric genitourinary oncology

Tumors of the kidney, bladder, prostate, testis, and adrenal represent a large part of the adult urologic practice, but are relatively infrequent in children. The natural history and management of these tumors in the pediatric age is different from that of the adults. As result of the successful work of several clinical trial groups in recent decades, there has been a significant improvement in their cure rates. The aim of this article is to review their most significant clinical aspects, as well as to present an update in their management.

Pediatric metanephric adenoma: case report and review of the literature

Metanephric adenomas are rare benign renal neoplasms, uncommonly seen in the pediatric population. They are typically detected incidentally on imaging studies performed for unrelated clinical presentations. Preoperatively, the imaging appearance of this tumor overlaps with the appearance of more common and more aggressive renal neoplasms such as Wilms' tumor or renal cell carcinoma. We present a case of a pathologically proven metanephric adenoma, monitored preoperatively for approximately 5 years, prior to definitive nephrectomy. As the majority of solid renal masses are resected soon after they are detected, to the best of our knowledge, this case is the first to demonstrate the natural in vivo progression of a pathologically proven metanephric adenoma.

Abdominal manifestations of neurologic disorders

A variety of disorders-including infectious, inflammatory, hereditary, and metabolic diseases-may affect both the brain and abdominal cavity, and the findings in one region may help establish the diagnosis or limit the differential diagnosis. Establishing an accurate early diagnosis enables clinicians to adequately manage these unusual diseases and potentially avert life-threatening complications. For example, an early diagnosis of Gardner syndrome enables annual sigmoid- or colonoscopy and ultrasonography. In many conditions, abdominal manifestations precede neurologic manifestations and may have prognostic significance. Patients with celiac disease more often present with abdominal manifestations such as duodenitis, slow transit time, reversal of the jejunal-ileal fold pattern, and transient small bowel intussusception than with intracranial manifestations. In other conditions, the neurologic manifestations may be the same as the presenting symptoms. For example, patients with Gardner syndrome may initially present with multiple mandibular or sinonasal osteomas. In addition, sarcoidosis may manifest with multifocal enhancing dural masses. Abdominal and neurologic manifestations may even occur simultaneously, as in several of the phakomatoses such as neurofibromatosis type 1, tuberous sclerosis complex, and von Hippel-Lindau syndrome. Ultimately, familiarity with the appearances of these conditions allows radiologists to pinpoint a diagnosis, even when imaging findings in either location are nonspecific.

Pituitary homeobox 2 (PITX2) protects renal cancer cell lines against doxorubicin toxicity by transcriptional activation of the multidrug transporter ABCB1

The multidrug resistance (MDR) P-glycoprotein ABCB1 plays a major role in MDR of malignant cells and is regulated by various transcription factors, including Wnt/β-catenin/TCF4. The transcription factor PITX2 (Pituitary homeobox-2) is essential for embryonic development. PITX2 operates by recruiting and interacting with β-catenin to increase the expression of growth-regulating genes, such as cyclin D1/2 and c-Myc. The importance of PITX2 in malignancy is not yet known. Here we demonstrate that in the renal cancer cell lines ACHN and A498, the level of ABCB1 expression and function correlate with nuclear PITX2 localization and PITX2-luciferase reporter gene activity (A498 > ACHN). In A498 cells, doxorubicin toxicity is augmented by the ABCB1 inhibitor, PSC833. PITX2 overexpression increases ABCB1 expression and cell survival in ACHN cells. Silencing of PITX2 by siRNA downregulates ABCB1 and induces a greater chemotherapeutic response to doxorubicin in A498 cells, as determined by MTT cell viability and clonogenic survival assays. Two PITX2 binding sequences were identified in the ABCB1 promoter sequence. PITX2 binding was confirmed by chromatin immunoprecipitation. β-Catenin is not required for PITX2 upregulation of ABCB1 because ABCB1 mRNA increased and doxorubicin toxicity decreased upon PITX2 overexpression in β-catenin(-/-) cells. The data show for the first time that ABCB1 is a target gene of PITX2 transcriptional activity, promoting MDR and cell survival of cancer cells.

A pediatric renal lymphoma case presenting with central nervous system findings

In pediatric patients renal lymphoma frequently presents in the form of multiple, bilateral mass lesions, infrequently as a single or retroperitoneal mass, and rarely as diffuse infiltrative lesions. In patients with apparent central nervous system involvement close attention to other physical and laboratory findings are essential for preventing a delay in the final diagnosis. Herein we present a pediatric patient with renal lymphoma that presented with central nervous system findings that caused a delay in diagnosis.

CONFLICT OF INTEREST

None declared.

Clear cell sarcoma of the kidney misdiagnosed as mesoblastic nephroma: a case report and review of the literature

Clear cell sarcoma of the kidney (CCSK) is a rare renal neoplasm of paediatrics, making up about 3% of all renal tumours in paediatrics, with a high tendency for developing bone metastasis. A seven year-old boy was referred to our clinic with two firm, large masses over the manubrium of the sternum and right frontal area, which pathologically were confirmed as a metastatic CCSK. The patient had a history of a renal mass three years earlier, for which radical nephrectomy had been performed, and histopathologic diagnosis was compatible with mesoblastic nephroma. Thus, no further investigation and therapy had been applied for the patient. CCSK is a rare but malignant and aggressive paediatric renal tumour, with a high tendency for developing distant bone metastases, leading to its poor prognosis. CCSK could be misdiagnosed as several other renal tumours such as mesoblastic nephroma, and thus CCSK should be taken carefully into consideration in the diagnosis of renal tumours.

Imaging spectrum of primary malignant renal neoplasms in children

Wilms' tumor (WT) is the most common abdominal tumor in children. Many pediatric renal tumors in the past were categorized as WT; however, in recent years, several specific renal tumors have been recognized as distinct pathological entities. The age and clinical presentation of the child and distinctive imaging features may help in reaching a specific diagnosis in most cases. This is important as it has implications on the pre-operative diagnostic work-up and prognosis of the child. However, it is often not possible to differentiate one from the other pediatric renal tumor on the basis of imaging alone, and the final diagnosis is often made at histological examination of the surgical specimen. This article reviews the imaging features of primary malignant renal neoplasms in children along with their clinical presentation and pathological features.

Cellular mesoblastic nephroma with liver metastasis in a neonate: prenatal and postnatal diffusion-weighted MR imaging

Congenital mesoblastic nephroma (CMN) is the most common renal tumor in the first year of life. Here, we present unique findings of cellular variant CMN seen on prenatal and postnatal MRI with diffusion-weighted imaging (DWI).The mass was well-visualized on prenatal MR DWI with diffusion restriction in the solid portions. After excision of the mass, follow-up whole body MRI with DWI helped identify local tumor recurrence with suspicious liver metastasis. This hepatic lesion also showed diffusion restriction.

SIOP PODC: clinical guidelines for the management of children with Wilms tumour in a low income setting

Wilms tumour is a relatively common and curable paediatric tumour. Known challenges to cure in low income countries are late presentation with advanced disease, malnutrition, failure to complete treatment and limited facilities. In this article, management recommendations are given for a low income setting where only the minimal requirements for treatment with curative intent are available (setting 1). These include general management, supportive care, social support and registration of patients. Recommendations specific for Wilms tumour care include diagnostic procedures with emphasis on the role of ultrasonography, preoperative chemotherapy with a reduced dosage for malnourished children and postoperative chemotherapy based on surgical staging.

Wnt signaling in kidney development and disease

The Wnt gene family, which encodes secreted growth and differentiation factors, has been implicated in kidney organogenesis. The Wnts control both ureteric bud development and signaling, but they also serve as inductive factors to regulate nephrogenesis in the mesenchcymal cells. Several of the Wnt genes are expressed in the developing kidney, and gene knock-out studies have revealed specific developmental functions for these. Consistent with this, changes in Wnt ligands and pathway components are associated with many kidney diseases, including kidney cancers, renal fibrosis, cystic kidney diseases, acute renal failure, diabetic nephropathy and ischaemic injury. It is these associations of the Wnt signaling system with kidney development and kidney diseases that form to topic of this review.

A case of ossifying papillary renal cell carcinoma

Osseous metaplasia can occur in renal cell carcinomas. We report a case of a 52-year-old lady who presented with hematuria. Ossification associated with a renal cell carcinoma was demonstrated on computed tomography urography and confirmed by histopathologic examination.

Pediatric non-Wilms' renal tumors: a third world experience

BACKGROUND

Pediatric non-Wilms' renal tumors (NWRT) are poorly understood owing to their heterogeneity and relative rarity. This study aimed at auditing the outcome of the management of NWRT in a tertiary hospital in the Third World.

METHODS

Records of all patients (n = 68) treated for NWRT over a 32-year period (1978-2010) were reviewed retrospectively.

RESULTS

The major histological groups included clear cell sarcoma of the kidney (CCSK) (33.8%), mesoblastic nephroma (17.6%), cystic partially differentiated nephroblastoma (CPDN) (17.6%), intrarenal neuroblastoma (8.8%), malignant rhabdoid tumor (MRT) (7.4%), and renal cell carcinoma (RCC) (5.9%). Sixteen (69.7%) patients with CCSK and 11 (91.7%) with CPDN were aged 1-4 years. Ten (83.3%) patients with mesoblastic nephroma were aged <1 year and three (60.0%) with RCC were aged 10-14 years. Ten (43.5%) patients with CCSK and four (80.0%) with RCC had metastases at diagnosis. The sensitivity of a pretreatment Tru-Cut biopsy was 100% for MRT. All the patients with CCSK, mesoblastic nephroma, CPDN, and RCC had radical nephrectomy. Only eight (34.8%) patients with CCSK received radiotherapy. The overall 1-10-year survival rates were 52.2%, 91.7%, 75.0%, 40.0% and 0.0% for CCSK, mesoblastic nephroma, CPDN, RCC, and MRT, respectively. The overall 1-10-year survival for the entire cohort was 51.5%.

CONCLUSIONS

The demography and clinical presentation of pediatric NWRT, which comprises 13.6% of pediatric renal tumors in the Third World, were similar to those in the Developed World. The overall 1-10-year survival for pediatric NWRT was low.

Common and uncommon adult unilateral renal masses other than renal cell carcinoma

Many different masses can involve the kidney other than the commonly encountered renal cell carcinoma (RCC). The purpose of this article is to review the characteristic clinical and imaging findings of common and uncommon masses that predominantly present unilaterally in the adult patient, other than RCC. Awareness of such lesions and knowing the clinical scenario is important for appropriate diagnosis and management, especially in a multidisciplinary care setting.