1/60. Classical congenital mesoblastic nephroma in an adult: a case report on an Ethiopian. A 54-year-old Ethiopian woman presented to Tikur Anbessa Hospital with left flank pain and left renal tumour mass in October 1996, and biopsy from nephrectomy specimen was reported as classical congenital mesoblastic nephroma (CMN). The clinical presentation, laboratory data and the pathologic findings of the patient are described in detail. In ethiopia, there is no report of congenital mesoblastic nephroma of adulthood. In this report, the clinical presentation and the pathological features of congenital mesoblastic nephroma are also reviewed from available literature. ( info) |
2/60. Prenatal sonographic diagnosis of a fetal renal mesoblastic nephroma occurring after transfer of a cryopreserved embryo. Here we report the first case of prenatally diagnosed fetal renal mesoblastic nephroma occurring after transfer of a cryopreserved embryo. A 37 year old woman, having immunological infertility, was treated by in-vitro fertilization (IVF) and embryo transfer. Following unsuccessful IVF using fresh embryos, the patient conceived after transfer of cryopreserved-thawed embryos. The chromosomal analysis identified a normal karyotype at 16 weeks' gestation when amniocentesis was performed. The pregnancy course was uneventful until 28 weeks' gestation when polyhydramnios associated with fetal renal tumour was detected using ultrasonography. A male infant weighing 2564 g was born via Caesarean section at 34 weeks' gestation. A left nephrectomy was performed 5 days after delivery and the tumour was identified histologically as a mesoblastic nephroma. The postoperative course was uncomplicated to this point. ( info) |
3/60. Congenital cystic mesoblastic nephroma. Congenital mesoblastic nephroma is a relatively rare infantile renal tumor. It comprises 3-6% of renal masses in childhood and 50% during the neonatal period. Most mesoblastic nephroma occur in the newborn period, with 80% of the cases being reported within the first month of life. Macroscopically the tumor is composed of a solid mass of different sizes tending to invade the surrounding structures and renal parenchyma. The authors report a case of cystic mesoblastic nephroma of the cellular subtype, with diffuse areas of hemorrhage and necrosis. The tumor was treated by surgical excision with radical nephrectomy and the child is doing well 4 years after the operation. ( info) |
4/60. Congenital mesoblastic nephroma (CMN) with an unusual immunohistochemical feature. OBJECTIVES: To describe a case of congenital mesoblastic nephroma (CMN) treated by radical nephrectomy with no evidence of relapses after five years in spite of an unusual positivity for proliferating cellular nuclear antigen (PCNA). methods: A three-month-old child presented a right renal mass with compression of the inferior vena cava. Excretory urography showed an intrarenal mass with distortion of the calyceal system. There was no evidence of metastasis. Radical nephrectomy was carried out; no adjuvant therapy was given. Histological and immunohistochemical studies were performed. RESULTS: The tumor was a 6 x 6 x 5 cm solitary mass extending into perirenal tissue, involving the hilar vessels but not the ureter. Histologically, it has been classified as a congenital mesoblastic nephroma of the classic variant. Positive reaction for vimentin and actin was observed. Strong positivity for PCNA and negativity for P53 were revealed. CONCLUSIONS: PCNA is considered to be a reliable marker of potential malignancy. This, however, contrasts with the biological behavior of our case. Further evaluation is required for correct interpretation of this additional information and to avoid inappropriate aggressive therapy. ( info) |
5/60. Mesoblastic nephroma in adulthood: a case report. BACKGROUND: Mesoblastic nephroma is an uncommon renal tumor of infancy and rarely occurs in adults. We report an adult case of mesoblastic nephroma. methods: A 50-year-old woman was found incidentally to have a right renal mass by abdominal ultrasonography. Computed tomography and magnetic resonance imaging revealed a heterogeneous tumor and angiography showed a mixture of hypervascularity and hypovascularity. Right radical nephrectomy was performed. RESULTS: The tumor was an encapsulated yellowish 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. CONCLUSION: The patient was free of recurrence 14 months postoperatively. Mesoblastic nephroma is classified as a benign tumor but recurrence and malignant formation of this tumor have been reported so regular postoperative follow up is required. ( info) |
6/60. Detection of the ETV6-NTRK3 chimeric rna of infantile fibrosarcoma/cellular congenital mesoblastic nephroma in paraffin-embedded tissue: application to challenging pediatric renal stromal tumors. We report the development of a reverse transcriptase polymerase chain reaction assay that reliably detects the ETV6-NTRK3 chimeric rna characteristic of infantile fibrosarcoma and the cellular variant of congenital mesoblastic nephroma (CMN) in formalin-fixed, paraffin-embedded tissue blocks. The 188 base pair polymerase chain reaction fusion product was detected in 11 of 12 cases of cellular CMN from which a larger sized control rna band could be amplified, and even in 7 of 8 cases in which the control band was not detectable. A variety of other tumors that are in the histologic differential diagnosis of cellular CMN yielded negative results, including four classic CMNs, four rhabdoid tumors of the kidney, and four clear cell sarcomas of the kidney, confirming the assay's specificity. We further demonstrate the assay's utility by illustrating two cases of molecularly confirmed cellular CMN that mimicked rhabdoid tumor and clear cell sarcoma of the kidney. In contrast to previous reports, five mixed CMNs that had both classic and cellular areas all lacked the ETV6-NTRK3 fusion transcript. These results suggest that cases morphologically defined as mixed CMN may represent a mixed group of genetically distinct entities. ( info) |
7/60. adult mesoblastic nephroma. We report a case of asymptomatic mesoblastic nephroma in a 54-year-old woman. The tumor showed immunohistochemical reactions similar to developing nephrons. Electron microscopy showed immature tubules with numerous intracytoplasmic intermediate filaments. Recent studies support the concept of pathogenesis of the mesoblastic nephroma originating from collecting ducts. However, this case exhibited a complex pattern of antigenic expression not restricted to the collecting ducts, but including the glycoprotein CD24 and the neural cell adhesion molecule (NCAM). The following differential diagnoses will be discussed: benign mixed epithelial and stromal tumor, metanephric adenoma, and nephrogenic adenofibroma. ( info) |
8/60. Congenital mesoblastic nephroma: report of a Case with review of the most significant literature. AIMS AND BACKGROUND: Congenital mesoblastic nephroma (CMN) is a rare pediatric tumor of the kidney with the highest peak of incidence during the first 3 postnatal months. It has previously been confused with Wilms' tumor (which, on the contrary, is rare during the first six months of age and is still considered a histogenetic congener). CMN almost always has a favourable prognosis. Therefore, CMN needs to be correctly diagnosed and differentiated from other pediatric renal neoplasms. Two morphological subtypes are currently distinguished histologically: the classical or leiomyomatous type and the atypical or cellular type. Mixed forms with a combination of the two patterns are also on record. recurrence and even tumor-related death have been described in the literature and always related to the atypical form or to the mixed form, particularly in patients aged more than 3 months and in those cases in which the surgical removal was not complete. Opinions concerning post-surgical clinical management, especially in regard to adjuvant therapy, are not unanimous. methods: A case of CMN, predominantly of the classical histological subtype diagnosed in a baby with a follow-up of 6 years, is herein presented. The tumor was discovered at birth and surgically removed after one month. Since the tumor showed a high mitotic index (one of the characteristics of the cellular subtype) and the perirenal fat was focally involved with the tumor, the possibility of giving adjuvant chemotherapy was considered. Flow cytometric analysis was also performed which showed a diploid dna content of neoplastic cells. RESULTS: The tumor was completely removed, surgical margins were free histologically, and no clear-cut histological features of the atypical subtype were noted. Flow cytometrically, it showed the euploid dna content. Consequently no additional therapy was given. Six years after surgery the patient is developing well and is free of disease. He has regular follow-up examinations. CONCLUSIONS: CMN almost always pursues a benign clinical course if diagnosed under three months of age and if totally surgically excised independent of histological type. Criteria for management of atypical cases are not unanimous in regard to the benefit of additional therapy after surgery. ( info) |
9/60. Mesoblastic nephroma: prenatal ultrasonographic and MRI features. Antenatal detection of mesoblastic nephroma by US is possible. Reviewing the literature, we found 19 previously reported cases, only 1 of which underwent prenatal MRI. We present a further case diagnosed by US and confirmed with MRI. The imaging findings and differential diagnoses are discussed. Early and correct detection of this rare entity is of great interest, as it may facilitate prevention and management of severe obstetric and neonatal complications such as polyhydramnios and prematurity. MRI can help to evaluate the origin and the morphological features of a fetal abdominal mass. ( info) |
10/60. adult mesoblastic nephroma with ciliated epithelium. A case report. A case of renal pelvic tumors occurring in a 44-year-old man is reported. There were two polypoid renal pelvic tumors which consisted of glandular and stromal components. Some glands in the tumors had ciliated epithelium and were quite similar to the epididymal tubules. Other glands in the tumors resembled the collecting duct or the mesonephric remnant seen in female genitalia. immunohistochemistry and electron microscopy revealed smooth muscle differentiation of the stromal cells of these tumors. Some psammoma bodies were seen in the glands of the tumors. We diagnosed these tumors as adult mesoblastic nephroma (MN). The patient has been followed up for 14 months, showing no evidence of recurrence. Differentiation of the tumors from angiomyolipoma, leiomyoma, and nephrogenic adenofibroma is discussed. adult renal tumors that consist of epithelial and stromal components have been reported under various names. They constitute clinicopathologically different entities originating from pediatric MN. We suggest that these tumors should be termed "adult MN". ( info) |