Regression of a congenital mesoblastic nephroma

Infantile Congenital Mesoblastic Nephroma Leading to Multi-Systemic End-Organ Disease

Congenital mesoblastic nephroma (CMN) is a rare infantile abdominal tumor that is highly curable with early surgical intervention. However, chronic, unrecognized tumor burden can cause significant compression of local vascular and solid structures, resulting in multi-systemic end-organ dysfunction. In this case report, we describe the effects of chronic abdominal compartment syndrome in an infant due to a solid renal tumor and its anesthetic implications.

Congenital mesoblastic nephroma: a single-centre series

BACKGROUND

Congenital mesoblastic nephroma is a rare disease. Treatment is surgical in the first instance. Chemotherapy has traditionally been thought not to have a role. Recent literature suggests a 50% mortality rate for recurrent/metastatic disease.

MATERIALS AND METHODS

This study is a retrospective case review of prospectively collected data. Demographics, histopathology, treatment, outcomes and follow up were reviewed.

RESULTS

Nine patients, 6 male and 3 female, were included. The median age at presentation was one month (range 0-7 months); follow-up was for a median of 21.5 months (range 16-79 months). Two patients had mixed and classical subtypes and the other five had the cellular subtype. Surgery was completed by an open procedure in eight patients and laparoscopically in one. There were three recurrences; two were local and one was pulmonary. Recurrences were treated with a combination of chemotherapy, radiotherapy and surgery. One patient with recurrent disease died from acute-on-chronic respiratory failure secondary to lung irradiation but was disease free. The other eight are disease free, alive and well with no sequelae at latest follow-up.

CONCLUSIONS

Surgery remains the mainstay of management with chemo- and radiotherapy reserved for unresectable tumours or adjuvant management of recurrent disease. Specimen-positive margins are not an indication for instituting chemotherapy. The tyrosine kinase pathway seems to be a potential target for future chemotherapeutic agents although it is too early to assess how that will impact on the management of congenital mesoblastic nephroma.

Prenatal diagnosis of congenital mesoblastic nephroma: a case with poor prognosis

Congenital mesoblastic nephromais a rare tumour found in neonates, with a very small number of cases diagnosed prenatally. We report a case of a fetal renal tumour suspected at 28 weeks' gestation on routine ultrasound. Prenatal follow-up revealed a severe polyhydramnios at 32 weeks' gestation subsequent amniodrainage was undertaken. She delivered at 34+5 weeks' gestation, after spontaneous premature rupture of membranes.

The Value of Mitotic Count and Ki67 Proliferation Index in Congenital Mesoblastic Nephroma

OBJECTIVE

We aimed to define the histopathologic features and proliferative rate of congenital mesoblastic nephroma (CMN) as a risk factor for recurrence.

METHODS

Fourteen cases of CMN among 138 registered pediatric renal tumors were retrospectively reviewed. The prognostic impact for mitotic rate and Ki67 index was investigated.

RESULTS

There were four (28.6%) classic, six (42.9%) cellular, and four (28.6%) mixed type CMNs, with average Ki-67 counts of 16.75% in the classic CMN, and 53.2% in the tumors with cellular components (both mixed and cellular CMNs). Twelve patients (85.7%) were aged less than six months. Tumors with cellular component showed significantly larger tumor diameter and higher Ki-67 index (p = 0.015 and p = 0.016, respectively). The patient with cellular CMN, whose tumor showed the highest mitotic rate (4.9/HPF), but not the highest Ki67 index (57.4%), died of recurrent disease with distant metastasis.

CONCLUSION

Proliferative markers-mitotic count and Ki67 index-have limited value to predict recurrence or metastasis in CMNs with a cellular component.

Congenital mesoblastic nephroma: Clinical analysis of eight cases and a review of the literature

Congenital mesoblastic nephroma (CMN) is a mesenchymal renal tumor. The aim of the present study was to review the clinical characteristics and outcome of CMN in infants. A retrospective file review was conducted of eight cases of CMN treated at the Children’s Hospital of Fudan University between 2004 and 2012. Ultrasound and computerized tomography scans had been performed on all eight patients. Two cases presented with a solid tumor and exhibited pathological features consistent with those of classic CMN, five cases exhibited cystic, hemorrhagic and necrotic characteristics, with calcification and pathology consistent with the cellular variant of CMN and one case presented with a solid tumor, which exhibited pathological features consistent with ceullular CMN. Histology confirmed classic CMN in two patients and cellular CMN in six patients. For surgical intervention, four cases had radical nephrectomy, one case had a half nephrectomy and three cases had tumor enucleation performed. Two cases had received pre-operative chemotherapy, but exhibited no response, and three cases received post-operative chemotherapy. Two patients were lost to follow-up, but the remaining six patients survived to the end of follow-up without further complications. The mean follow-up time was 24.6 months. In conclusion, the differential diagnosis between CMN and Wilms’ tumor is critical. Imaging characteristics are partially correlated with pathological characteristics. Surgery is the main treatment for CMN, but pre-operative chemotherapy is not particularly effective. The efficacy of post-operative chemotherapy requires further investigation, but the prognosis is positive.

Renal and hepatic tumors in the neonatal period

Renal and hepatic tumors in neonates are extremely rare. Nevertheless it is important for clinicians to be familiar with them. Both renal and hepatic neonatal tumors are heterogeneous collections of several tumor types. Some renal and hepatic tumors are benign and may require no interventions whereas others can be associated with significant morbidity and even mortality and may require multimodality treatment. Early diagnosis and initiation of the proper treatment plan is crucial for achieving the best outcomes for these rare tumors in this vulnerable population.

[Fibrosarcoma in children and adolescents: different entities for the same name]

Fibrosarcomas (FS) are rare malignant tumors in pediatrics, classified in the heterogeneous non-rhabdomyosarcomas group of malignant mesenchymal tumors. Infantile FS are found typically in children less than 2 years of age, and include congenital FS usually occurring in infants in the first 3 months of life. Histological diagnosis can be difficult; and confirmed with detection by molecular biology of the ETV6-NTRK3 fusion protein. FS is most often a localized disease at diagnosis, with involvement of an extremity. The management of these patients must be multidisciplinary, to define the different phases of treatment and avoid mutilating surgery. Cellular or atypical mesoblastic nephroma (MN) is a subtype of malignant pediatric renal tumors, most often present in children of less than 3 months. Histopathological characteristics of the cellular MN are very close to the congenital FS due to a fusion transcript common to both diseases. Treatment schedule is defined by initial local stage of the disease. FS called "adult-type" found exceptionally in childhood occur most often after 10 years old. Adult FS differ from infantile FS in their clinical presentation because of a strong local aggressiveness and problematic appearance of metastasis in 50% of cases, sometimes late. These three diseases present therefore histological similarities. Both have a common name but different clinical presentation and outcome: infantile FS and adult FS. Two have different names and initial location but similar histology, chromosomal rearrangement, sensitivity to chemotherapy and outcome: the congenital FS and cellular mesoblatic nephroma. Authors present a review of the literature of these entities.

Pediatric fibroblastic and myofibroblastic lesions

Fibrous lesions of infancy and childhood are a heterogeneous group of entities composed predominantly of fibroblasts and myofibroblasts, ranging from reactive lesions to neoplasms with a range of malignant potential. Although rare, their correct recognition by histopathology is important clinically as they exhibit a wide range of behaviors and may be associated with distinct underlying syndromes. Contributions from molecular diagnostics have enabled more accurate diagnosis, and have changed our concepts of some tumor types. In this review, we discuss the clinicopathologic spectrum of fibroblastic and myofibroblastic lesions of childhood and adolescence.