How to improve initial diagnostic accuracy of kidney tumours in childhood?-A non-invasive approach.

Non-invasive differentiation of paediatric kidney tumours is particularly important in the SIOP-RTSG protocols, which recommend pre-operative chemotherapy without histological confirmation. The identification of clinical and tumour-related parameters may enhance diagnostic accuracy. Age, metastases, and tumour volume (TV) were retrospectively analysed in 3306 patients enrolled in SIOP/GPOH 9, 93-01, and 2001 including Wilms tumour (WT), congenital mesoblastic nephroma (CMN), clear cell sarcoma (CCSK), malignant rhabdoid tumour of the kidney (MRTK), and renal cell carcinoma (RCC). WT was diagnosed in 2927 (88.5%) patients followed by CMN 138 (4.2%), CCSK 126 (3.8%), MRTK 58 (1.8%) and RCC 57 (1.7%). CMN, the most common localized tumour (71.6%) in patients younger than 3 months of age, was diagnosed earliest and RCC the latest (median age [months]: 0 and 154, respectively) both associated with significantly smaller TV (median TV [mL]: 67.2 and 45.0, respectively). RCC occurred in >14% of patients older than 120 months or older than 84 months with TV <100 mL. Receiver operating characteristic analyses discriminated WT from CMN, RCC and MRTK regarding age (AUC = 0.976, 0.929 and 0.791) and TV (AUC = 0.768, 0.813 and 0.622). MRTK had the highest risk of metastasis (37.9%) despite young age, whereas the risk of metastasis increased significantly with age in WT. Age and TV at diagnosis can differentiate WT from CMN and RCC. MRTK must be considered for metastatic tumours at young age. Identification of CCSK without histology remains challenging. Combined with MRI-characteristics, including diffusion-weighted imaging, and radiomics and liquid biopsies in the future, our approach allows optimization of biopsy recommendations and prevention of misdiagnosis-based neoadjuvant treatment.

Report and follow-up on two new patients with congenital mesoblastic nephroma.

BACKGROUND: Tumors are rare in neonatal age. Congenital mesoblastic nephroma (CMN) is a usually benign renal tumor observed at birth, or in the first months of life. It may also be identified prenatally and associated with polyhydramnios leading to preterm delivery. Effective treatment is surgical in most cases, consisting in total nephrectomy. In literature, very few studies report on the neonatal management of such a rare disease, and even less are those describing its uncommon complications. CASES PRESENTATION: We report on two single-center newborns affected with CMN. The first patient is a preterm female baby, born at 30+ 1 weeks of gestation (WG) due to premature labor, with prenatal (25 WG) identification of an intra-abdominal fetal mass associated with polyhydramnios. Once obtained the clinical stability, weight gain, instrumental (computed tomography, CT, showing a 4.8 × 3.3 cm left renal neoformation) and histological/molecular characterization of the lesion (renal needle biopsy picture of classic CMN with ETV6-NTRK3 translocation), a left nephrectomy was performed at 5 weeks of chronological age. The following clinical course was complicated by intestinal obstruction due to bowel adherences formation, then by an enterocutaneous fistula, requiring multiple surgical approaches including transitory ileo- and colostomy, before the conclusive anastomoses intervention. The second patient is a 17-day-old male term baby, coming to our observation due to postnatal evidence of palpable left abdominal mass (soon defined through CT, showing a 7.5 × 6.5 cm neoformation in the left renal lodge), feeding difficulties and poor weight gain. An intravenous diuretic treatment was needed due to the developed hypertension and hypercalcemia, which regressed after the nephrectomy (histological diagnosis of cellular CMN with ETV6-NTRK3 fusion) performed at day 26. In neither case was chemotherapy added. Both patients have been included in multidisciplinary follow-up, they presently show regular growth and neuromotor development, normal renal function and no local/systemic recurrences or other gastrointestinal/urinary disorders. CONCLUSIONS: The finding of a fetal abdominal mass should prompt suspicion of CMN, especially if it is associated with polyhydramnios; it should also alert obstetricians and neonatologists to the risk of preterm delivery. Although being a usually benign condition, CMN may be associated with neonatal systemic-metabolic or postoperative complications. High-level surgical expertise, careful neonatological intensive care and histopathological/cytogenetic-molecular definition are the cornerstones for the optimal management of patients. This should also include an individualized follow-up, oriented to the early detection of any possible recurrences or associated anomalies and to a better quality of life of children and their families.

Congenital Mesoblastic Nephroma: A Case Report.

Congenital mesoblastic nephromas are rare renal tumours that are encountered in paediatric age group. A term female neonate at the end of first week of life presented with bilateral lower limb swelling. On radiological evaluation, ultrasonography revealed an intra-abdominal mass which was managed with radical nephroureterectomy. Histopathological examination confirmed a diagnosis of congenital mesoblastic nephroma of mixed subtype. Keywords: case reports; congenital mesoblastic nephroma; kidney neoplasms; nephrectomy.

Congenital mesoblastic nephroma: review of current management and outcomes in a single centre.

BACKGROUND: Congenital mesoblastic nephroma (CMN) is a rare tumour of the kidney with an overall excellent prognosis. Once considered a benign tumour, it is now recognized to carry a risk of recurrence and metastases with subsequent poor outcomes. The potential for genetic aberrations such as ETV6-NTRK3 fusion raises the potential for targeted treatments in certain patients. The optimum mode and frequency of surveillance is unclear. This study aims to assess this institution's experience with CMN and long-term outcomes. METHODS: A single centre retrospective review was performed of all confirmed cases of CMN between October 2001 and January 2021. RESULTS: Nine cases of CMN in patients under 12 months of age were identified. The histopathology, management and outcomes of these patients are discussed. CONCLUSION: CMN overall has a very good prognosis, but a subgroup does exist that will have poor outcomes. It is difficult to accurately identify this group to target adjuvant therapy.

Non-Wilms' renal tumors in children: experience with 139 cases treated at a single center.

BACKGROUND: Pediatric non-Wilms renal tumors (NWRTs), which comprise a small proportion of renal tumors, are a heterogeneous group of neoplasms with variable malignant potential, mortality, and response to treatment. We performed this study to determine the clinical characteristics, management and prognosis of children with Pediatric NWRTs. METHODS: Medical records of all patients (n = 139) treated for NWRTs over a 12-year period (2008.01-2019.10) at a single center were reviewed retrospectively. RESULTS: The histopathological groups of NWRTs included malignant rhabdoid tumor of the kidney (MRTK) (n: 30, 21.6%), renal cell cancer (RCC) (n: 26,18.7%), clear cell sarcoma of the kidney (CCSK) (n: 24,17.3%), congenital mesoblastic nephroma (CMN) (n: 21,15.1%), cystic nephroma (CN) (n: 16,11.5%), metanephric tumors (n: 12, 8.6%), renal angiomyoliporma (RAML) (n: 3, 2.2%), renal primitive neuroectodermal tumor (n: 2, 1.4%), renal hemangioma (n: 2, 1.4%), inflammatory myofibroblastic tumor (n: 2, 1.4%), ossifying renal tumor of infancy (ORTI) (n: 1, 0.7%). The distribution of all malignant NWRTs, including MRTK, CCSK, RCC and PNET, according to stage was as follows: stages I (n = 26), II (n = 16), III (n = 29), and IV (n = 11). The summary table shows the treatment offered to children with NWRTs. A total of 123 children were followed up for an average of 42 months. Sixteen children were lost to follow-up. Tumor-free survival was observed in 94 children. One patient who suffered from RCC is currently receiving targeted therapy and survives with the tumor. Twenty-eight children (22.8%) died. CONCLUSIONS: Pediatric NWRTs comprise 19.1% of all renal tumors in our single center. Most NWRTs can readily be distinguished using a range of immunohistochemical markers. Molecular genetic profiling has allowed much progress in the understanding of this group of tumors, making diagnosis and classification less difficult. The mainstay treatment of malignant NWRTs, including MRTK, CCSK, RCC and PNET, is comprehensive treatment. The mainstay treatment of benign NWRTs, including RAML, CN, ORTI, CMN, metanephric tumors, and renal hemangioma, is surgical resection alone and when the tumor diameter is smaller than 7 cm and the tumor locates in one pole, NSS can be performed.

Neonatal congenital mesoblastic nephroma that caused respiratory oncologic emergency early after birth: a case report.

BACKGROUND: Congenital mesoblastic nephromas mainly present as asymptomatic abdominal masses, but some present hematuria, hypertension or hypercalcemia. Neonatal dyspnea in an early-birth neonate due to rapid tumor growth is reported here for the first time. CASE PRESENTATION: A renal tumor and polyhydramnios were detected by ultrasonography of a male fetus at 32 weeks and 3 days of gestation. The mother had abdominal distension due to the polyhydramnios and signs of imminent premature birth. Amniocentesis was performed and the signs of imminent preterm birth subsided, but growth of the renal tumor was noted as a potential cause of respiratory dysfunction. Cesarean section was performed at 36 weeks and 2 days of gestation. His birthweight was 2638 g and his 1 and 5 min APGAR scores were 2 and 4 points, respectively. There was no spontaneous breathing at birth and he had remarkable abdominal distention. He underwent cardiopulmonary resuscitation. After circulation stabilized, emergency surgery was performed because of progressive hypoxemia and respiratory acidosis. Laparotomy revealed a huge tumor arising from the right kidney and right nephrectomy was performed. Histopathological examination led to diagnosis of congenital mesoblastic nephroma. The respiratory condition and circulatory dynamics stabilized after the pressure on the thorax from the tumor was relieved by surgery. The postoperative course was uneventful. No recurrence or complications have been observed in the 36 months since the surgery. CONCLUSIONS: Congenital mesoblastic nephroma can rapidly increase in size from the fetal period and may cause respiratory oncologic emergency, although there is relatively good prognosis.

Imaging of Prenatal and Neonatal Intra-abdominal Genitourinary Tumors: a Review of the Literature.

PURPOSE OF REVIEW: Our goal was to summarize current literature related to imaging of intra-abdominal genitourinary tumors diagnosed in the prenatal or neonatal period. Our specific interests included modalities used, diagnoses made, changing incidence of tumor detection, and proposed future uses of these imaging modalities. RECENT FINDINGS: Fetal and neonatal MRI have been used as an adjunct to ultrasound for better characterization and assessment of congenital mesoblastic nephroma, juvenile granulosa cell tumor, and other tumors. Despite recent literature describing fetal and neonatal MRI, it is not yet possible to determine whether its use is changing the incidence of tumor detection. Improvements in imaging technology, specifically the use of fetal MRI, have allowed for earlier identification of genitourinary masses with improved capability for diagnosis, surveillance, surgical planning, and sometimes prenatal treatment of the malignancy and related diagnoses, with a goal of preventing pregnancy and delivery complications.

Severe neonatal hypercalcemia revealing congenital mesoblastic nephroma: A case report and management of neonatal hypercalcemia: Severe neonatal hypercalcemia revealing congenital mesoblastic nephroma.

Congenital mesoblastic nephroma is a rare pediatric renal tumor and has been reported in patients presenting with palpable abdominal mass, arterial hypertension, hematuria, polyuria, or hypercalcemia. Here we present the case of a 1-month-old neonate with suspected parathyroid hormone (PTH)-related peptide (PTH-rp)-mediated severe hypercalcemia revealing congenital mesoblastic nephroma. Preoperatively, hypercalcemia was corrected with hydration, furosemide, pamidronate, and low-calcium infant formula. Unilateral nephrectomy led to the resolution of hypercalcemia, transient hyperparathyroidism, and transient vitamin D and mineral supplementation. We conclude that congenital mesoblastic nephroma can secrete PTH-rp that can cause severe hypercalcemia.

Prenatal diagnosis of fetal congenital mesoblastic nephroma by ultrasonography combined with MR imaging: A case report and literature review.

RATIONALE: Fetal congenital mesoblastic nephroma (CMN) is a rare renal tumor, characterized by polyhydramnios, premature birth, and neonatal hypertension. In the prenatal stage, it is particularly difficult to diagnose CMN either by ultrasonography or magnetic resonance imaging (MRI). Thus, CMN is frequently detected in the third trimester in the clinical scenario. PATIENT CONCERNS: A 29-year-old G2P0 pregnant woman took routine prenatal examinations in our hospital. The fetal right kidney abnormality was not observed after 2 systematical ultrasonic examinations (at 24 and 31 weeks of gestation respectively), and only an increase was noticed in the amniotic fluid index (from 19.3 to 20.8 cm). DIAGNOSIS: CMN was detected by antenatal ultrasonography and MRI as a fetal right renal mass at 35 weeks of gestation in our hospital. INTERVENTIONS: The pregnant woman was admitted at a gestational age of 38 weeks and 5 days due to alterations in renal function. Further, the pregnant woman was administered with "oxytocin" to promote delivery, and the neonate underwent a right nephrectomy on the 9th day after birth. OUTCOMES: The pathological examination confirmed a cellular type of right CMN. The neonate recovered well after operation without adjuvant treatment. During 6 months of follow-up, the neonate grew well and showed no signs of recurrence or metastasis. CONCLUSION: Polyhydramnios detected during prenatal examination required attention due to the risk of malformation of fetal urinary system. Prenatal ultrasonography combined with MRI could not only clearly identify the origin of the tumor, but also distinguish the correlation between the tumor and adjacent structures, thereby leading to early diagnosis and favorable prognosis.

Congenital Mesoblastic Nephroma Presenting with Hematuria in a Neonate.

Congenital mesoblastic nephroma (CMN) is a rare tumor of infancy. CMNs can be histologically divided into classic, cellular, and mixed subtypes. Cellular CMNs are difficult to differentiate from Wilms tumors. Herein, a neonate with cellular CMN accompanied by macroscopic hematuria, is described. The clinical, pathological, and imaging features of the disease are discussed.

A rare cause of neonatal hypertension: Congenital mesoblastic nephroma.

Soyaltin E, Alaygut D, Alparslan C, Özdemir T, Arslansoyu-Çamlar S, Mutlubas F, Kasap-Demir B, Yavascan Ö. A rare cause of neonatal hypertension: Congenital mesoblastic nephroma. Turk J Pediatr 2018; 60: 198-200. A rare cause of neonatal hypertension: Congenital Mesoblastic Nephroma (CMN) is a rare renal tumor in childhood and has been reported with palpable abdominal mass, hypertension, hematuria, polyuria and hypercalcemia. Histopathologically it has been classified into two histological types: classic and cellular. We present a 32-week gestation infant and his histopathology reports of cellular CMN presented with refractory hypertension.

Management of mixed type congenital mesoblastic nephroma: Case series and review of the literature.

Congenital mesoblastic nephroma (CMN) is the most common renal tumor of infancy; however, it occurs infrequently with an incidence of 1 : 125,000. The cellular and classical variants are the most common subtypes of tumors, with a mixed variant occurring infrequently. We describe two cases of mixed variant CMN, which presented within days of each other differing in their clinical behavior. The first case followed a typical course, previously described in the literature, while the other deviated significantly. Traditionally, CMN presents as large abdominal mass in the neonatal period associated with a paraneoplastic syndrome, which can result in hypertension or hypercalcemia. Surgical resection is curative in most cases and long-term prognosis is excellent. Hypertension rarely persists after removal of the tumor, but remained in one of our two patients.

Renal Tumors in Children Younger Than 12 Months of Age: A 65-Year Single Institution Review.

Wilms tumor (WT) is the most prevalent pediatric renal tumor and most commonly occurs between ages 1 and 5 years. Data are lacking on children younger than 12 months with renal tumors. The cancer registry at the authors' institution was queried to identify patients 12 months and younger with renal masses. Demographics, clinical presentation, histopathology, stage, and survival outcomes were reviewed. The most common presenting symptoms included an asymptomatic abdominal mass (73%) and hematuria (9%). Histopathology revealed WT in 73% of patients, mesoblastic nephroma in 20%. Of those infants younger than 1 month of age, mesoblastic nephroma was the most common histopathology (68%). The 5-year overall survival (OS) was 93%, and 5-year event-free survival (EFS) was 93% for the entire group. For patients with WT, 5-year OS was 88% and 5-year EFS was 83%. Outcomes for congenital mesoblastic nephroma were excellent with 5-year OS and EFS of 100%. Reasons for good prognosis may be multifactorial and may include frequent well child checks in the first year of life and favorable histology. Patients in this age group are more likely to be classified as very low risk and may be treated with surgical resection alone.

Renal Function Recovery after Nephrectomy or Nephron-Sparing Surgery in Children with Unilateral Renal Tumor.

Introduction Children with unilateral renal tumor (URT) and preoperative renal dysfunction (PRD) may benefit from nephron-sparing surgery (NSS). To test this hypothesis, we studied the outcome of baseline renal function after nephrectomy or NSS among children with URT. Materials and Methods Retrospective records review of children with URT who underwent nephrectomy (25 children) or NSS (11 children) at our institution. We analyzed the estimated glomerular filtration rate (eGFR) changes over time among patients, stratified by both preoperative renal function (with or without PRD) and surgical extent (NSS vs. nephrectomy). The primary end point was evaluation of compensatory recovery of preoperative eGFR after surgery. Only children older than 2 years at surgery were included in the study. Renal dysfunction was defined as an eGFR < 90 mL/min/1.73 m2. Results After nephrectomy or NSS, patients with PRD presented, on average during adolescence, a significant increase in eGFR, whereas patients without PRD presented, on average during adolescence, a stable eGFR. However, after nephrectomy, 5 of 17 (29%) and 7 of 8 (87%) adolescent patients with baseline eGFR ≤ or > 100 mL/min/1.73 m2, respectively, achieved or maintained two-kidney eGFR values (T-KEV) (p = 0.01). After NSS, four adolescent patients with PRD and seven without PRD achieved or maintained T-KEV. Conclusion The majority of children with URT and low baseline eGFR present with an impaired renal function recovery after nephrectomy and may benefit from NSS. Collaborative studies are needed to support present findings.

Mesoblastic Nephroma in a 22 Years Old Woman.

Mesoblastic nephroma is an uncommon renal tumor of infancy and rarely occurs in adults. We report a case of mesoblastic nephroma in adult. A 22-year-old woman, who presented with left flank pain, was found to have a left renal mass by abdominal ultrasonography. Computed tomography revealed a heterogeneous tumor. Left radical nephrectomy was performed. The tumor was a creamy white solid mass. Microscopically, the tumor was composed of spindle cell proliferation. Atypia and mitoses were not identified. Among the tumor cells, there were tubular arranged epithelial elements. The patient was free of recurrence 18 months postoperatively. Mesoblastic nephroma is classified as a benign tumor but recurrence and malignant transformation of this tumor have been reported, so regular postoperative follow up is required.

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.

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.

Maternal manifestation of Ballantyne's syndrome occurring concomitantly with the development of fetal congenital mesoblastic nephroma.

Various fetal or placental disorders cause Ballantyne's (mirror) syndrome. For the first time, we report a maternal manifestation of Ballantyne's syndrome occurring concomitantly with the development of fetal congenital mesoblastic nephroma (CMN). In a pregnant woman with a CMN fetus, lung edema, hypertension, hyperthyroidism, and high serum human chorionic gonadotrophin level occurred, all of which characterize maternal manifestation of Ballantyne's syndrome. The fetus and placenta were devoid of 'edema', lacking 'triple edema', and thus this condition was not diagnosed as Ballantyne's syndrome; however, we considered this condition as the maternal manifestation of Ballantyne's syndrome. We performed emergent cesarean section at 28 weeks. Delivery acutely ameliorated maternal symptoms. Tumor was resected and was confirmed as CMN. Maternal manifestations of Ballantyne's syndrome, such as lung edema and hypertension, can occur in a mother with fetal CMN even without fetal and/or placental edema. The clinical course of this patient may suggest an etiology of Ballantyne's syndrome.