Nefroma mesoblastico congénito: reporte de un caso / Congenital mesoblastic nephroma: case report

El nefroma mesoblastico congénito es un tumor renal infrecuente, pero común en el periodo neonatal. De comportamiento benigno y pronóstico excelente en su variedad clásica pero en el subtipo celular puede presentar recurrencia local, invasión retroperitoneal y metástasis pulmonares y cerebrales. El tratamiento es la nefrectomía radical. Los factores pronósticos son la edad menor a tres meses y la resección quirúrgica completa. Paciente de 17 días nacida a las 35 semanas por polihidramnios, con diagnóstico prenatal de masa abdominal. Al examen físico masa en flanco derecho e hipertensión arterial (121/79 mm Hg, TAM 77mm Hg). Ecografía abdominal con riñón derecho aumentado de tamaño y voluminosa formación sólida, de 4,4 x 4,3 x 4,8 cm, heterogénea y vascularizada al Doppler en polo inferior. Tomografía de abdomen con formación nodular heterogénea de 5,0 x 4,1 x 5,1 cm en polo inferior del riñón derecho. Se realizó nefrectomía radical derecha sin complicaciones. Evolución en los últimos 20 meses satisfactoria y libre de enfermedad.

Congenital mesoblastic nephroma is an uncommon renal tumor, but frequent in neonates. Classical variety usually benign with excellent prognosis. Cellular cases may be recurrent with retroperitoneal invasion, brain and lung metastasis. Radical nephrectomy is the treatment of choice. Relevant prognostic factors are diagnosis before three months of age and complete resection. A 17 day old patient, borned at 35 weeks due to polyhydramnios, with prenatal diagnosis of abdominal mass. On examination, right flank abdominal mass and arterial hypertension (121/79 mm Hg, MAP 77 mm Hg). Abdominal ultrasound showed an enlarged right kidney with a voluminous solid heterogeneous mass, 4.4 x 4.3 x 4.8 cm in the lower pole, vascularized on Doppler scan. Computed tomography showed a big 5.0 x 4.1 x 5.1 cm, nodular, heterogeneous mass in the lower pole of the right kidney. Right radical nephrectomy was performed with an uneventful recovery. Follow up for the last 20 months satisfactory and free of disease.

Renal Tumors in Children / 임상소아혈액종양

Pediatric renal tumors represent a diverse group, which include Wilms' tumor (WT), renal cell carcinoma (RCC), clear cell sarcoma of the kidney (CCSK), congenital mesoblastic nephroma, malignant rhabdoid tumor of the kidney (MRTK) and primitive neuroectodermal tumor. WT (85%) and RCC (8%) are the most prevalent types. WT predominates among the 1- to 10-year age group, but RCC exceeds WT in children over age 10 years. Pediatric renal tumors are genetically, histologically and clinically heterogeneous. The overall survival for children with localized WT is currently more than 90%, whereas poorer survival rates are observed for anaplastic WT, metastatic WT, metastatic CCSK, MRTK, metastatic RCC and relapsed WT. Therefore risk-stratified treatment is important to minimize treatment morbidity while preserving survival. This review focuses on distinct characteristics of each tumor type and optimal stratified treatment.

Renal Tumors in Children / 임상소아혈액종양

Pediatric renal tumors represent a diverse group, which include Wilms' tumor (WT), renal cell carcinoma (RCC), clear cell sarcoma of the kidney (CCSK), congenital mesoblastic nephroma, malignant rhabdoid tumor of the kidney (MRTK) and primitive neuroectodermal tumor. WT (85%) and RCC (8%) are the most prevalent types. WT predominates among the 1- to 10-year age group, but RCC exceeds WT in children over age 10 years. Pediatric renal tumors are genetically, histologically and clinically heterogeneous. The overall survival for children with localized WT is currently more than 90%, whereas poorer survival rates are observed for anaplastic WT, metastatic WT, metastatic CCSK, MRTK, metastatic RCC and relapsed WT. Therefore risk-stratified treatment is important to minimize treatment morbidity while preserving survival. This review focuses on distinct characteristics of each tumor type and optimal stratified treatment.

Prenatal diagnosis of congenital mesoblastic nephroma

Congenital mesoblastic nephroma is a rare renal tumor that is diagnosed during pregnancy and is associated with polyhydramnios, prematurity, and neonatal hypertension. Differential diagnoses include Wilms tumor, adrenal neuroblastoma, and other abdominal tumors. We report a case of congenital mesoblastic nephroma detected by prenatal ultrasonography as a large fetal renal mass with polyhydramnios at 32 weeks of gestation. Ultrasonography showed a 6x6-cm complex, solid, hyperechoic, round mass in the right kidney. At 35 weeks of gestation, the patient was admitted with preterm premature rupture of membranes and the baby was delivered vaginally. Postnatal ultrasonography and computed tomography showed a heterogeneous solid mass on the right kidney. At the end of the first week of life, a right nephrectomy was performed and subsequent pathological examination confirmed a cellular variant of congenital mesoblastic nephroma with a high mitotic count. Postoperative adjuvant chemotherapy was administered. The newborn was discharged in good condition.

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.

Diagnóstico prenatal ecográfico de nefroma mesoblástico congénito / Sonographic prenatal diagnosis of congenital mesoblastic nephroma

El nefroma mesoblástico congénito es la neoplasia renal primaria más común vista en el primer mes de vida. Intraútero aparece como una gran masa vascular sólida. Frecuentemente se manifiesta con polihidramnios. Es benigno y la nefrectomía postnatal es curativa. Describimos el caso de una paciente que cursa una gestación de 29 semanas y discutimos los hallazgos en las imágenes abdominales fetales

Nefroma mesoblástico congênito subtipo celular: relato de caso / Cellular congenital mesoblastic nephroma: case report

INTRODUÇÃO: Nefroma Mesoblástico Con-gênito é uma rara neoplasia renal pediátrica. Apresenta dois subtipos histológicos, clássico e celular, sendo o último de pior prognóstico e responsável por aproximadamente dois terços dos casos. Esse tumor ainda é um desafio diagnóstico aos patologistas devido à similaridade com outras neoplasias pediátricas renais mais frequentes. RELATO DO CASO: Criança do gênero feminino, 2 anos e 9 meses de idade, foi encaminhada a serviço médico com referência em oncologia apresentando massa renal à esquerda. Após nefrectomia, o estudo do espécime mostrou, macroscopicamente, extensa área tumoral granular, brancoacinzentada, ocupando aproximadamente todo o rim, invadindo seio renal, cápsula e gordura perirrenal, com áreas de hemorragia e necrose. Histologicamente, caracterizava-se pela presença de células fusiformes e mitoses, sem atipias celulares. O diagnóstico foi de Nefroma Mesoblástico Congênito subtipo celular e a paciente foi submetida a quimioterapia. Durante o primeiro ano de tratamento, houve recidiva do tumor, apresentando-se irressecável e sem resposta a nova quimioterapia. A paciente foi a óbito aos 4 anos de idade. DISCUSSÃO: O subtipo celular do nefroma mesoblástico tende a ser mais agressivo, apresentando uma taxa de sobrevivência de 85 por cento, comparada com 100 por cento para a variante clássica. Geralmente, a recorrência ocorre no primeiro ano de tratamento, principalmente quando o subtipo é o celular.

INTRODUCTION: Congenital Mesoblastic Nephroma (CMN) is a rare pediatric renal tumor. It comprises two histological subtypes, namely classic and cellular, with the second accounting for two thirds of all cases and being more often associated with poor prognosis. It remains a diagnostic challenge for pathologists due to its similarity with other more frequent pediatric kidney neoplasms. CASE REPORT: We describe the case of a 2-year- old girl who presented with a left renal mass. After nephrectomy, the specimen analysis showed, on gross examination, an extensive, granular and whitish tumor lesion occupying almost the entire kidney, invading the renal sinus, capsule and perirenal fat, with areas of hemorrhage and necrosis. Histologically, it was characterized by ovoid spindle cells, mitoses and no cell atypia, which led to a diagnosis of cellular mesoblastic nephroma. Adjuvant chemotherapy was carried out, but tumor recurrence occurred in the first year, presenting as an unresectable tumor that did not respond to adjuvant chemotherapy and the patient died at 4 years of age. DISCUSSION: The cellular variant tends to be more aggressive, with a survival rate of 85 percent versus 100 percent for the classic variant. Recurrence generally occurs in the first year, particularly with the cellular variant.

Clinicopathologic analysis of mixed epithelial and stromal tumor of kidney and adult cystic nephroma / 中华病理学杂志

<p><b>OBJECTIVE</b>To study the clinicopathologic features, immunophenotype and differential diagnosis of mixed epithelial and stromal tumor of kidney (MEST) and adult cystic nephroma (CN).</p><p><b>METHODS</b>Five cases of MEST and 4 cases of CN were retrospectively analyzed. Immunohistochemical study was carried out and the literature was reviewed.</p><p><b>RESULTS</b>All of the five patients with MEST were females. Their median age was 45 years. For CN, there were 3 males and 1 female and their median age was 41 years. All patients presented with loin pain and hematuria. On gross examination, MEST was well-circumscribed but non-encapsulated. There was no evidence of haemorrhage or necrosis. Three of the cases were solid in nature. One was composed of a mixture of solid and cystic elements, while the remaining case showed a multicystic cut surface bridged by thick fibrous septa. On the other hand, CN were well-circumscribed and encapsulated. They were multiloculated cystic in nature. The cystic spaces were separated by thin septa and there was no significant solid or necrotic component. Histologically, MEST consisted of proliferation of cystically dilated glands admixed with spindly stromal cells with various cellularity and growth patterns. Both the glandular and stromal elements were well-differentiated with no cytologic atypia identified. The glandular structures in 2 of the cases were partially lined by endometrial or tubal epithelium. In contrast, the thin-walled cystic spaces in CN were lined by a single layer of epithelium.Immunohistochemical study showed that the epithelial cells were positive for pan-cytokeratin and epithelial membrane antigen. The spindle cells in MEST expressed vimentin (5/5), smooth muscle actin (3/5), desmin (4/5), CD10 (5/5), estrogen receptor (4/5) and progesterone receptor (4/5). They were negative for HMB45, CD34, CD117 and S-100 protein. On the other hand, the spindle cells in CN were variably positive for vimentin (4/4), smooth muscle actin (4/4), desmin (1/4), estrogen receptor (3/4) and progesterone receptor (1/4). They were negative for CD10, HMB45, CD34, CD117 and S-100 protein.</p><p><b>CONCLUSIONS</b>Both MEST and CN are uncommon renal neoplasm. Most of them run a benign clinical course. The stromal cells in MEST show smooth muscle or myofibroblastic differentiation. Areas demonstrating Müllerian features also existed in some cases. MEST and CN share overlapping histological and immunohistochemical features, and may represent spectrum of the same group of lesions.</p>

Mixed Epithelial and Stromal Tumor of the Kidney: A Case Report

The descriptive term "mixed epithelial and stromal tumor of the kidney" was recently proposed for a group of renal tumors characterized histologically by a mixture of stromal and epithelial proliferation. It is a rare benign neoplasm of the kidney which has been reported under various names such as adult type mesoblastic nephroma or others. We report a case of mixed epithelial and stromal tumor in a 47 yr old female patient presenting as a partly cystic and partly solid renal mass. Microscopically, the tumor exhibited spindle cell component in solid portion and epithelial proliferation around microcystic areas. Immunoreactive profiles and ultrastructural examination suggested myofibroblastic nature of the stromal cells. We believe this case exemplifies a unique adult renal tumor displaying both epithelial and stromal neoplastic component and has a few unusual features worthy of attention.

A Case of Fetal Congenital Mesoblastic Nephroma with Oligohydramnios

Although congenital renal tumors are rare, congenital mesoblastic nephroma (CMN) is the most common renal tumor in early infancy. It is non-metastatic, well differentiated, amenable to surgical removal, and carries a good prognosis. Polyhydramnios has been detected in most of the published cases of CMN. However, we experienced a rare case of fetal CMN associated with oligohydramnios. A 28-yr old woman at 34 weeks of gestation was referred to our hospital for oligohydramnios and a fetal abdominal mass. An ultrasonography revealed a huge, well-encapsulated mass arising from the right kidney. An emergency cesarean section was performed due to fetal distress. After birth, despite intensive neonatal care, the baby died because of renal failure, disseminated intravascular coagulopathy, pulmonary edema, together with other problems.

Unusual Mesoblastic nephroma: a report of two cases

Congenital mesoblastic nephroma [CMN] is a very rare tumour of early infancy with 80% of the cases being diagnosed within the first month of life. Complete surgical excision is almost always curative. We report two unusual large renal tumours in a 22-month-old boy and a 4-year-old girl who were diagnosed preoperatively as rhabdoid tumour and Wilms' tumour respectively. One of them was subjected unnecessarily to preoperative chemotherapy. Histological evaluation after complete radical excision demonstrated CMN

Nefroma mesoblástico congénito. Variante multiquística / Congenital mesoblastic nephroma. Multicystic variant

Se presenta un caso de Nefroma Mesoblástico Congénito (NMC) en un paciente de un año y cinco meses de edad que ingresa por un cuadro diarreico agudo, constatándose en el exámen médico una tumoración abdominal. La ecografía y la tomografía computada de aparato urinario evidenciaron proceso expansivo renal multiquístico derecho. Se realizó nefrectomía diagnosticándose, por el estudio anatomopatológico, nefroma mesoblástico congénito, variante celular a forma multiquística. La evolución fue favorable no presentando evidencias de recidiva local ni metástasis luego de dos años y cuatro meses de seguimiento. Se destaca la importancia del exámen físico exhaustivo durante los controles pediátricos periódicos, lo que permite un diagnóstico temprano de las masas abdominales.

Multilocular Cyst of Kidney with Malignant Recurrence / 대한비뇨기과학회지

A multilocular cyst of kidney is a rare pathological entity, which has been reported in the literature under several names. These various names reflect the controversy surrounding their nature. This tumor is traditionally regarded as benign in nature and a nephrectomy has to be performed because of the difficulty in its accurate diagnosis. Malignant recurrence of a multilocular cyst of kidney has an even rarer incidence, with only a few cases having been reported. We report a case of 50-year-old male, with an incidentally detected right renal cystic mass. This mass was pathologically confirmed as a multilocular cyst of kidney after a radical nephrectomy, which locally recurred as a malignant mesoblastic nephroma.

Mesoblastic nephroma of infancy.

This report presents features of mesoblastic nephroma, a rare benign tumor of kidney observed in perinatal period of life and highlights the role of imaging investigations in the proper management of this tumor. Awareness of this tumor may facilitate prevention and management of severe obstetric and neonatal complications and inadvertent and vigorous therapy compatible with that of Wilms' tumor can be avoided.

Imaging Diagnosis of Fetal Abdominal Solid Tumor / 대한산부인과학회잡지

OBJECTIVE: Ultrasonography is screening modality of choice and plays an important role in prenatal diagnosis of various diseases and neoplasm of fetus. Recently, Magnetic Resonance Imaging was used as a diagnosis tool to fetal disease. We would like to evaluate efficacy of ultrasonography and magnetic resonance imaging for the diagnosis of fetal abdominal solid tumor. METHODS: Among 2,055 cases of abnormal ultrasonography findings detected by prenatal ultrasonography from January 1996 and June 2002, a comparison between the diagnosis made by prenatal ultrasonography, fetal magnetic resonance imaging (MRI), postnatal radiological studies and histopathologic studies was made in four cases with fetal abdominal solid tumor. RESULTS: The first case was diagnosed as adrenal tumor or hepatic tumor by US, hemangioedothelioma of liver by fetal MRI, and confirmed as hemangioendothelioma postnatally. The second case showed concordance with mesoblastic nephroma among the diagnosis made by US, fetal MRI, and postnatal histopathologic studies. The third case was diagnosed as extrathoracic pulmonary sequestration by US and MRI, and the same diagnosis was made by postnatal histopathologic studies. The fourth case was suspected as kidney tumor by US and was diagnosed as adrenal as adrenal neuroblastoma postoperatively. CONCLUSION: Fetal solid tumor is not a common disorder, but the location, size and orgin of tumor plays important role in the prognosis of neonatal period; additional workup by fetal MRI would improve the diagnosis of such tumors.

Nefroma mesoblástico infantil: informe de un caso clínico y revisión bibliográfica / Mesoblastic nephroma in children: report of a clinic case and bibliographic revision

En una paciente pediátrica de 2 meses y medio se detecta por ecografía un tumor en el polo superior del riñón derecho, que debutó clínicamente por hematuria. Los exámenes de ingreso demostraron buen estado general, ausencia de masa abdominal palpable, y exámenes de laboratorio normales. La TAC abdominal confirma una masa de 3,1x 2,5cm., sin invasión aparente de la grasa perirrenal.Se somete a laparotomía exploradora que demuestra un tumor renal derecho que ocupa un 80 por ciento de éste órgano, sin compromiso ganglionar hiliar ni paraaórtico, en tanto que el riñon izquierdo está indemne.El estudio histológico concluyó que se trata de un nefroma mesoblástico, tumor infrecuente y que debe diferenciarse rigurosamente del tumor de Wilms, pues su pronóstico casi siempre es muy bueno sólo con cirugía. Se describe la lesión y los métodos aplicados para el diagnóstico diferencial. Los autores revisan la literatura disponible de estas lesiones, raras en la práctica clínica habitual

A Case of Lung Metastasis of Mesoblastic Nephroma in Adulthood / 결핵

Mesoblastic nephroma is a neoplasm of the kidney which is characterized by interlacing bundles of spindle mesenchymal cells. It is usually diagnosed during the first six months of life and is mostly benign. Incidence in adults is exceedingly rare. In most cases, only total excision is required without postoperative adjuvant therapy, and the rare cases of local recurrence have usually been related to incomplete removal. However, mesoblastic nephroma may behave aggressively, in contrast to a congenital mesoblastic nephroma. Several cases of metastatic mesoblastic nephroma have been previously described. We report herein a case of a 42-year-old woman with mesoblastic nephroma which recurred as a large metastatic lung mass seven years after the nephrectomy. The patient presented with chest wall discomfort for four days. Seven years previously, total nephrectomy had been performed because of a right renal tumor which had been diagnosed as a mesoblastic nephroma. There had been no evidence of recurrence for five years, after which she discontinued follow-up. On readmission two years later, chest X-ray and CT scan revealed a large lung mass in the left upper lobe. It was completely excised and the pathologic examination was identical with that of the original renal tumor. Synovial sarcoma was excluded because the fusion transcripts of the SYT-SSX fusion gene associated with the t(X;18) translocation were negative. The final diagnosis was a lung metastasis of mesoblastic nephroma and the patient remained free of disease for 7 months postoperatively.