Congenital Mesoblastic Nephroma Mimic Wilms Tumor on 18 F-FDG PET/CT and PET/MR.

ABSTRACT: Congenital mesoblastic nephroma is an extremely rare, low-grade malignant renal tumor in children. A 10-month-old boy and a 4-month-old girl were admitted to our hospital with a huge abdominal mass. For staging of the mass, 18 F-FDG PET/CT and PET/MR were performed showing a huge heterogeneous abdominal mass accompanied by extensive heterogeneous aggregation. Both of them were highly suspected to be Wilms tumor, the most common renal malignant tumor in children. However, histopathological examination after surgery confirmed congenital mesodermal nephroma.

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.

Unusual Case of Concurrent Retroperitoneal Congenital Infantile Fibrosarcoma and Cellular Type Congenital Mesoblastic Nephroma.

BACKGROUND: Although congenital infantile fibrosarcoma (cIFS) is a rare soft tissue sarcoma among children, it constitutes one of the most common soft tissue sarcomas during the first year of life. Congenital mesoblastic nephroma (CMN) is the most common benign renal tumor usually developing during the first 3 months of life. cIFS and cellular type CMN (cCMN) share not only similar histopathologic features but identical molecular genetic abnormality including the ETV6/NTRK3 fusion gene. Here, we report an unusual case of cIFS occurring with cCMN. CASE PRESENTATION: An 18-month-old girl presented with a 1-month history of abdominal distension and a few days' history of a palpable abdominal mass. A large heterogenous mass sized 9.0×11.2×11.6 cm on the right side of the abdomen and an isolated heterogenous lesion sized 4×4.5 cm within the right kidney were noted from the imaging study. Pathologic findings were consistent with cIFS and cCMN of the right kidney. In addition, both pathologic specimens contained the ETV6/NTRK3 fusion gene. CONCLUSION: Although cIFS and cCMN share similar histopathologic features and molecular genetic abnormality, simultaneous occurrence of these 2 types of tumor is exceedingly rare. To our knowledge, this is the first unusual case report of concurrent cIFS and cCMN.

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.

Congenital Mesoblastic Nephroma Presenting With Refractory Hypertension in a Premature Neonate: A Case Study.

The most common nonencapsulated solid renal tumor in the neonatal period is congenital mesoblastic nephroma. Mesoblastic nephroma is a solid lesion originating within or extending from the renal parenchyma. These tumors proliferate rapidly, typically within 3-6 months after birth. Mesoblastic nephromas are stratified by classification as either classical (benign) or atypical (malignant); masses composed of both benign and malignant cells are also reported. The hallmark clinical manifestation of mesoblastic nephroma is a palpable abdominal mass, which may be accompanied by hypertension, hypercalcemia, hematuria, and polyuria. Differentiating between benign and malignant renal tumors is essential to invoke a timely, evidence-based management and treatment plan. With appropriate surgical intervention in a timely manner, prognosis is excellent and mesoblastic nephroma is considered curable. We present a case involving a premature infant with congenital mesoblastic nephroma with discussion of embryology, pathophysiology, diagnostic, management, and prognostic implications for the neonate and family.

Congenital Mesoblastic Nephroma Presenting With Hematuria in a Neonate: A Case Report.

Congenital mesoblastic nephroma (CMN) is the most frequent renal neoplasm of newborns and young infants. Four cases presenting with hemorrhagic manifestations have been reported in the English literature (Hu et al, 2006; Bolande et al, 1967). We report the unusual clinical and radiographic findings of a 2-day-old neonate with hematuria secondary to a CMN. The first ultrasound was equivocal. Repeat ultrasound followed by magnetic resonance imaging confirmed the diagnosis. He underwent a right nephroureterectomy with histopathology revealing a cellular variant of CMN without classical translocation (t12:15). Neonates presenting with hematuria require close follow-up and serial imaging to rule out occult renal tumors. Classical translocation may not be demonstrable in all the cases.

Congenital mesoblastic nephroma: Its diverse clinical features - A literature review with a case report.

To characterise congenital mesoblastic nephroma (CMN), with special emphasis on polyhydramnios and the neonatal prognosis, we summarise 31 CMN patients (30 reported patients and the present patient). CMN was detected at a median of 30 weeks' gestation, and infants were delivered at a median of 34 weeks' gestation. Of 27 patients with available data, 19 (70%) had polyhydramnios, of which 8 required amnio- drainage. Women with amnio-drainage gave birth significantly earlier (30.4 weeks' gestation) than those without polyhydramnios (36.7 weeks' gestation). Thus, CMN was frequently associated with polyhydramnios and this polyhydramnios was associated with a significant increase in the risk of preterm birth. Of 20 patients with available data, the affected-side kidney was 'compressed' in 16 and 'replaced' in 4: polyhydramnios was present in a half vs 100%, respectively, suggesting that a 'replaced' kidney may suggest a more aggressive tumour and may be associated with a poorer prognosis. Univariate analysis showed that early gestational week at diagnosis was the only feature significantly associated with poor prognosis. Thus, polyhydramnios, 'replaced' kidney and early gestational week at diagnosis, may indicate poor prognosis, to which obstetricians should pay attention.

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.

Nefroma mesoblástico congénito con hiperecogenicidad medular que simula nefrocalcinosis / Congenital mesoblastic nephroma with medullary hyperechogenicity simulating nephrocalcinosis

El nefroma mesoblástico congénito (NMC) es un tumor raro, siendo el más frecuente a nivel renal en los pacientes menores de 2 meses. Su origen histológico es la estroma renal inmadura, y se distinguen los subtipos clásico, mixto y celular. El tratamiento de elección es quirúrgico y su pronóstico es excelente. Se han descrito casos de NMC asociado a nefrocalcinosis en relación con la hipercalcemia paraneoplásica. Exponemos el caso de un recién nacido que presenta en la ecografía imágenes de hiperecogenicidad medular renal bilateral, similar a una nefrocalcinosis, en el contexto clínico de un NMC(AU)

Congenital mesoblastic nephroma (CMN) is a rare tumour which is the most frequent in the first 2 months of life. Its histological origin is the immature renal stromal cells. There are three histological subtypes: clasic, mixte and cellular. The treatment of choice is surgical and the prognosis is excellent. CMN has been reported associated with nephrocalcinosis in relation to paraneoplasic hypercalcaemia. We report a case of a new born with ultrasound imagen of renal medullary hyperechogenicity simulating nephrocalcinosis in the clinical setting of CNM(AU)

Parathyroid-hormone-related protein-mediated hypercalcemia in benign congenital mesoblastic nephroma.

Parathyroid hormone-related protein (PTHrP) mediated hypercalcemia of malignancy is rare in children, and even more so in the setting of a benign tumor. We report two infants with PTHrP-mediated hypercalcemia secondary to congenital mesoblastic nephroma and their outcome after removal of the benign tumor. Pre-operatively hypercalcemia was corrected with saline hydration, furosemide, calcitonin and/ or pamidronate. Following resection of the tumor serum PTHrP normalized. Immunohistochemical staining of tumor cells was positive for PTHrP. Post-operatively the infants developed elevated serum parathyroid hormone with low- normal serum Ca and P, and undetectable urinary Ca and P, probably due to their movement into bone. Children needed treatment with calcitriol, Ca and P supplementation for 6-12 weeks until PTH normalized and urinary Ca and P were detected, suggesting bone replenishment. We conclude that benign congenital mesoblastic nephroma can secrete PTHrP that can cause severe hypercalcemia; and following excision one should anticipate the development of a transient modified "hungry bone"-like condition requiring Ca, P and calcitriol therapy for several weeks accompanied by careful monitoring of mineral homeostasis.

Nefroma quístico multilocular aportación de 3 nuevos casos / Multilocular cystic nephroma. Report or three new cases

OBJETIVO: Analizar la forma con la cual se nos presenta el nefroma quístico multilocular y el enfoque diagnóstico- terapéutico que debemos realizar.MÉTODOS: Aportamos los 3 últimos nuevos casos que se nos han presentado en nuestro servicio en un periodo de 3 años.RESULTADO: El nefroma quístico multilocular es una lesión benigna, poco frecuente apareciendo en edad adulta, habitualmente de forma asintomática, y en edad infantil frecuentemente como masa palpable. Requiere realizar diagnostico diferencial con tumoraciones malignas.CONCLUSIONES: Se demuestra la gran variedad de presentaciones clínicas, diagnósticos diferenciales y lugares de procedencia de los casos, siendo esto un reflejo de nuestra practica médica diaria sin poder llegar al diagnostico definitivo mediante pruebas de imagen, siendo muy útil la aplicación de la clasificación de Bosniak para indicar la intervención quirúrgica que nos dará el diagnostico definitivo de nefroma quístico multilocular o lo que es más importante, nos descartará proceso maligno(AU)

OBJECTIVE: To analyze the presentation of multilocular cystic nephroma and its diagnostic-therapy scheme.METHODS: We report the three last new cases presenting in our department in a period of three years.RESULTS: Multilocular cystic nephroma is a benign lesion, rare that appears both in adult age, generally asymptomatic, and in children, frequently as a palpable mass. Differential diagnosis with malignant tumours is required.CONCLUSIONS: The great variety of clinical presentations, differential diagnosis and places of origin of the cases is demonstrated, being this a reflection of our daily medical practice, in which we cannot reach definitive diagnosis with imaging tests, being the Bosniak’s classification very useful for the setting of indication for surgery, which will give definitive diagnosis of multilocular cystic nephroma or what is more important will rule out malignancy(AU)

Tumores renales de la infancia y adolescencia asociados a anomalías cromosómicas / Renal tumors of childhood and adolescence associated with chromosomal anomalies

El riñón pediátrico es sitio frecuente de tumores que exhiben alteraciones cromosómicas características. El más común es el nefroblastoma o tumor de Wilms (TW) que se asocia con dos loci: 11p13 (WT1) y 11p15 (WT2 ó BWS), este último ligado también del síndrome de Beckwith-Wiedemann. Otros dos genes que parecen estar implicados son WT3 y WT4; además, dos anomalías específicas (adquisición 1q y deleción 22) se han correlacionado de manera independiente con un peor pronóstico en TW. Otras neoplasias con rearreglos cromosómicos, tales como los carcinomas renales (CRs), son mucho menos frecuentes en niños (entre el 1.8 y el 6.3% de todos los tumores renales malignos). Entre estos, se han identificado 'CRs con translocación' que afectan el locus Xp11, siendo los dos tipos más importantes t(X;1), y t(X;17). El nefroma mesoblástico congénito (NMC) es un tumor renal de recién nacidos y lactantes. Los NMCs de la variedad celular se caracterizan por una translocación específica t(12;15)(p13;q25), misma que se encuentra también en los fibrosarcomas congénitos extrarenales, y que permite establecer una correspondencia genética entre estos dos tumores (NMC y fibrosarcoma congénito). Los tumores rabdoides (TR) del riñón son neoplasias muy infrecuentes y muy agresivas, que aparecen con una edad promedio de 11 meses. Al menos 50% de los TRs muestran anormalidades en el gen hSNF5/INI1, situado en el locus 22q11.2. Este gen probablemente está involucrado en la modulación transcripcional de otros genes, tales como el oncogen c-Myc, y de la vía de transducción de la proteína RB-retinoblastoma

The pediatric kidney is a common site for tumors carrying specific chomosomal alterations. The most common of these is the nephroblastoma or Wilms tumor (WT), which is associated with anomalies in two loci: 11p13 and 11p15, the latter also linked to Beckwith-Wiedemann syndrome. Two other genes that seem to be implicated are WT3 and WT4. In addition, 1q gains or 22 deletions have been shown to independently be associated with a worst prognosis in WTs. Other neoplasms with chromosomal rearrangements, such as Renal Cell carcinomas (CRs) are much less frequent in children (between 1.8 and 6.3 % of all malignant renal tumors). Among these, the 'translocation renal carcinomas' have been identified involving the locus Xp11 with two main types of translocations: t(X;1), and t(X;17). Congenital mesoblastic nephroma (NMC) is a renal tumor affecting newborns and young infants. NMCs of the cellular type feature a specific translocation t(12;15)(p13;q25), which is also present in congenital fibrosarcomas outside of the kidney. These findings have led to conclude that these two tumors (NMC and congenital fibrosarcoma) are genetically equivalent. Rhabdoid tumors (TRs) of the kidney are very rare and aggressive neoplasms that appear with a mean age of 11 months. At least 50% of these TRs carry abnormalities in the hSNF5/INI1 gene, at 22q11.2. This gene is probably involved in transcriptional modulation of other genes such as the oncogene c-Myc, and also of the retinoblastoma protein RB signaling pathway

Congenital mesoblastic nephroma presenting with massive hematuria and hemorrhagic shock: report of one case.

Congenital mesoblastic nephroma (CMN) is a rare benign tumor that occurs during the neonatal period and early infancy. The vast majority of these tumors present as asymptomatic palpable abdominal masses. We describe an unusual presentation of a CMN in a 10-month-old male infant who presented with massive hematuria and the development of hemorrhagic shock. Abdominal ultrasound showed a heterogeneous solid complex mass measuring 4.8 x 3.5 cm arising from the upper pole of the left kidney. The patient was resuscitated using intravenous fluids and blood transfusions because persistent massive bloody urine leading to progressive shock occurred the night of the admission day. Preoperative diagnosis was possible Wilms tumor of the left kidney. The histopathological findings were consistent with the character of a cellular variant of CMN. The patient was free of recurrence and metastasis at the 2-year follow-up examination. Our case report suggests that CMN is a rare benign renal tumor during infancy and may present with unusual massive hematuria and shock.

The outcome of prenatally diagnosed renal tumors.

PURPOSE: We assessed the incidence of perinatal morbidity and evaluated the outcome in children with prenatally diagnosed renal tumors in a retrospective multicenter study. MATERIALS AND METHODS: A review of the records of patients from 20 institutions identified 28 children with prenatally diagnosed renal tumors. Prenatal findings, clinical charts, and radiological, surgical and pathological reports were reviewed in this study. RESULTS: There were 26 congenital mesoblastic nephromas and 2 Wilms tumors. One or more complications were identified in 20 of the 28 cases (71%) during the perinatal period. Polyhydramnios was observed in 11 fetuses (39%), 2 presented with hydrops fetalis and 7 presented in acute fetal distress requiring emergency cesarean section, of which 1 died in utero before delivery. Median gestational age of the 27 neonates born alive was 35 weeks (range 29 to 39), including 13 (46%) who were pre-term (less than 34 weeks of gestation). Complications at birth included hemodynamic instability in 3 newborns, of whom 2 underwent emergency surgery, respiratory distress syndrome in 8 (30%) and hypertension in 6 (22%). Surgical complications occurred in 7 patients (26%), including tumor rupture in 1 and intraoperative bleeding with postoperative death in 1. At a median followup of 42 months (range 2 to 105) 26 of the 27 children were in complete remission. CONCLUSIONS: Fetal renal tumors have an excellent oncological outcome but a high risk of perinatal complications. Prenatal diagnosis should allow planning the delivery at a pediatric tertiary care center to avoid a potentially life threatening condition in neonates in the first hours of life.