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.

Congenital mesoblastic nephroma: clinicopathological features and molecular genetic analyses / 临床与实验病理学杂志

To discuss clinicopathological features and molecular genetic change of congenital mesoblastic nephroma (CMN).Methods Nine cases diagnosed as CMN were analyzed retrospectively in this study.Histological features,immunohistochemical profiles and ETV6 gene rearrangement status were assessed.Results All patients were within two years of age and eight of them were within one year.The average diameter of tumors was 9.5 cm (3.2-15.0 cm).These series cases included 3 classic CMN,5 cellular CMN and 1 mixed CMN.Cystic degeneration was found in 5 cases,and cartilage islands were observed in 2 cases.Compared with classic CMN,tumor size was bigger,and hemorrhage,necrosis and mitotic figures were easily to see in cellular CMN.All the tumor cells were positive for vimentin and negative for WT-1 by immunohistochemistry.ETV6 gene rearrangement was detected in 5 cases (including 4 cellular CMN and 1 classic CMN).Three cellular CMN harbored ETV6 gene translocation,1 mixed CMN and 1 cellular CMN were negative for ETV6 gene translocation by FISH analysis.The follow up data were obtained in 7 cases and 2 cases were lost.All the 7 patients were alive without evidence of recurrence and metastasis from 5 to 46 months.Conclusion CMN is a rare infant renal tumor with unique clinicopathological characteristics.Most of cellular CMNs harbor ETV6 gene translocation.The prognosis of CMN is relative good and needs to be differentiated from other malignant renal tumors.

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.

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.

Atypical Mesoblastic Nephroma: A case report

Congenital mesoblastic nephroma (CMN) is generally considered to be a rare benign renal tumor in neonates, requiring only total excision. However, an atypical mesoblastic nephroma (AMN) may behave aggressively, in contrast to a congenital mesoblastic nephroma. AMN shows atypical gross and microscopic features such as hemorrhage, necrosis, high cellularity, and a mitotic index. We report a case of atypical mesoblastic nephroma which presented in a 2 month-old male infant. Grossly, the tumor involved the upper and the midportion of the left kidney. On section, the cut surface was flesh,which was hemorrhagic necrotic, multicystic degenerative, grayish-white, and heterogenous. Microscopically, the tumor showed a high degree of cellularity and an arrangement of monophagic ovoid spindle cells in sheets and vague interlacing bundles. The individual tumor cells showed fusiform to oval nuclei, indistinct scanty pale-eosinophilic cytoplasm, and many mitotic features.

Congenital Mesoblastic Nephroma

Mesoblastic nephroma is an important differential diagnosis of a renal mass occurring in the neonatal period or in early childhood. It is a rare monomorphous congenital renal neoplasm most commonly recognized during the first 3 months of life. With the widespread application of ultrasound imaging, many cases are recognized prior to birth. We report a case of mesoblastic nephroma detected by ultrasonograph at 36 weeks of intrauterine fetal life and removed after birth. It showed a well circumscribed, grayish white, solid mass measuring 4x3x2 cm. The tumor was predominantly a classic type with a focal cellular pattern. Immunohistochemical and electron microscopic studies were done.

Congenital Mesoblastic Nephromas with lmmunohistochemical and Flow Cytometric Analysis

We reviewed 7 cases of congenital mesoblastic nephroma (4 cases of classical mesoblastic nephroma (CMN) and 3 cases of atypical mesoblastic nephroma (AMN)) using immuno-histochemical and flow cytometric study. Results are as follows. 1) The mean tumor size was 5 (3 to 7cm)cm in CMN and 9 (7 to 10cm)cm in AMN. The AMN revealed hemorrhage and necrosis in two Of three cases. A case of AMN showed cystic change without hemorrhage and necrosis. Mitotic count ranged in 0~4/10HPF in CMN and 20-35/10HPF in AMN. 2) Immunohistochemistry for vimentin was all positive. Actin, desmin were weakly positive in CMN, but negative in AMN. The findings were consistent with myofibroblastic differentiation in CMN and AMN was considered to be the less differentiated form of CMN. 3) Flow cytometiic analysis showed diploidy in two of two CMNs and two of three AMNs. Only one AMN showed aneuploidy with DNA index of 1.41. %SG2M were 8.1 and 15.9 (mean 12.0) in CMN and 16.9, 32.9 and 19.3 (mean 22.9) in AMN, respectively. We concluded that AMN should be distinguished from CMN, clinicopathologically.

Atypical Mesoblastic Nephroma: Report of a case

Congenital mesoblastic nephroma(CMN) is an important differential diagnosis of a renal mass occurring in the newborn or in early childhood. It was first described by Bolande as a separate disease entity distinct form Wilms' tumor. In 1974, Beckwith has predicted that this tumor has a pathologic spectrum with classic congenital mesoblastic nephroma at one extreme, unequivocally mallignant spindle cell sarcomas at the other, and intermediate "gray zone" lesions of indeterminate biologic significanse. In 1986, Joshi has described "atypical mesoblastic nephroma" as a potentially aggressive variant of CMN, which shows atypical gross and microscopic features such as hemorrhage, necrosis, high cellularity, and mitotic index. We report of a case of atypical mesoblastic nephroma presenting in a 38 days-old male infant. Grossly, the tumor involved the upper and midportion of the left kidney. On section, the cut surface was fleshy, grayish-white, and homogeneous. Microscopically, the tumorshowed high degree of cellularity and arrangement of fusiform cells in sheets and vague interlacing bundles. The individual tumor cells showed fusiform to oval nuclei, indistinct scanty pale-eosinophilic cytoplasm and many mitotic figures.

A Case of Congenital Mesoblastic Nephroma / 대한비뇨기과학회지

Congenital mesoblastic nephroma is relatively rare congenital disease. It occurs in the early neonatal period as an unencapsulted and locally invasive fibrous lesion. Survival following nephrectomy alone is excellent but local recurrence and metastases have been reported. Herein we present one case of congenital mesoblastic nephroma. A 13-day-old male infant admitted our hospital with chief complaint of palpable left abdominal mass. After nephrectomy, histologic diagnosis is congenital mesoblastic nephroma.

A Case of Congenital Mesoblastic Nephroma

The congenital mesoblastic nephroma is the most common renal neoplasm seen in the first few months of life. This tumor usually benign, but local recurrences and metastases have been reported, and treatment is total nephrectomy. This entity must be differentiated from Wilm's tumor so as to avoid unnecessary postoperative irradiation and chemotherapy. Recently, we experienced a case of congenital mesoblastic nephroma in female newborn infant. Diagnosis was made with physical examination, plain roentgenogram of the abdomen, ultrasonography of the abdomen and I.V.P. and confirmed with microscopic examination. A brief review of the related literature was made on this subject.

A Case of Congenital Mesoblastic Nephroma

The congenital mesoblastic nephroma is the most common renal neoplasm seen in the first few months of life. This tumor usually benign, but local recurrences and metastases have been reported, and treatment is total nephrectomy. This entity must be differentiated from Wilm's tumor so as to avoid unnecessary postoperative irradiation and chemotherapy. Recently, we experienced a case of congenital mesoblastic nephroma in female newborn infant. Diagnosis was made with physical examination, plain roentgenogram of the abdomen, ultrasonography of the abdomen and I.V.P. and confirmed with microscopic examination. A brief review of the related literature was made on this subject.