WT (Wilms Tumor) is the most common renal tumor in children. It affects about 1 in 8,000 children with no significant sex predilection, and about 450 new cases reported each year in the United States. Ninety-eight percent of cases occur in children under 10 years and less than 300 cases of TW adults have been reported in the literature. It tends to occur with almost the same incidence throughout the world, suggesting the absence of an environmental factor. However, the incidence in the United States is highest among African Americans and lowest in Asians, suggesting a possible genetic redisposition.
Its true incidence in adults is difficult to determine since it is included with renal cell carcinoma in the epidemiological reports, and varying diagnostic criteria used in case reports. Currently, most experts use the following criteria to define adult WT (I) primary renal neoplasm, (ii) blastematous primitive spindle or round cell component, (iii) formation of the tubular structure or glomeruloid abortion or embryonic, (iv) any area of the tumor diagnosis of CRC, (v) a graphic confirmation of the histology, and (vi) age> 15 years. Approximately 1.2% of pediatric weights have a family background; however, this has not been reported in adults.
Pathology
In contrast to childhood turbines, which are often multicentric and bilateral, most adult cases are unincentric WEIGHT with multicentric and bilateral disease in 7 and 5% of patients, respectively. Horseshoe kidneys are associated with twice the incidence of WT. The macroscopic and microscopic appearance of WT adult it tends to resemble a pediatric weight. WT gross appearance is variable and reflects the proportion of stromal components and nonstromal. WT generally is pale gray or cream and has a soft, however, the predominant stromal tumors can be white and firm. cyst formation may be important in certain cases.
WEIGHT contains variable proportions of undifferentiated blast cells and differentiated cells of epithelial and stromal lineage. Blast cells are undifferentiated, small, active mitosis, rounded or oval, and densely populated, with little cytoplasm. Can occur in several distinctive growth patterns within individual tumors, including diffuse, nodular, serpentine, and basaloid. WT epithelial component may appear as rosette-shaped primitive tubules and occasional glomeruloid structures.
heterologous epithelial differentiation squamous epithelial components, mucinous, or hair can be detected. The stromal component may have great diversity, but is usually composed of spindle cells with a myxoid background. heterologous elements including skeletal muscle, cartilage, bone, fat and neural tissue may be present. WT histological diversity is a hallmark. Characteristically, it has a triphasic pattern with components called blast, epithelial and stromal. Chemotherapy can alter the morphology by inducing the maturation of the elements blast, epithelial and stromal that leads to a disproportionate reduction of actively proliferating cells compared with the sample prechemotherapy. WEIGHT Metastatic may comprise a single element or a combination of what is present in the primary tumor. WT-1 antigen is usually identified in the blast and epithelial elements, but not in differentiated epithelial and stromal components.
nuclear anaplasia associated with an adverse outcome has been recognized in 5% of pediatric cases and the increase in prevalence with age and in certain populations (eg African Americans). Anaplasia requires the presence of multipolar mitotic figures, marked nuclear enlargement (three times higher than that of anaplastic nuclei) and nuclear hyperchromasia. The prognostic significance is deeper in the diffuse anaplasia compared with focal anaplasia. Large blast cells have also been identified as an adverse prognostic factor.
Nephrogenic rests are abnormally persistent foci of embryonic kidney tissue are capable of becoming WT. The presence of diffuse or multifocal nephrogenic rests is
defined as nephroblastomatosis. There are two variants of nephrogenic rests perilobular called nephrogenic rests (PLNR) and intralobar nephrogenic rests (ILNR). Can be seen in 25-45% of WT were pediatric and adult patients seen in WT as well as in several ectopic sites outside the kidney.
Pediatric weight has been associated with a number of known syndromes and genetic mutations. WAGR (Wilms tumor, aniridia, genitourinary anomalies, mental retardation) and Denys-Drash syndrome (gonadal dysgenesis, nephropathy early onset) syndromes associated with deletion or mutations of the WT1 gene (11p13), a gene critical for development renal and gonadal. The Beckwith-Wiedemann syndrome (hemihypertrophy, macroglossia, omphalocele, and organomegaly) is associated with loss of imprinting of WT2 (11p15). Due to lack of enough cases, genetics and syndromic associations have not been well elucidated in adults.
Clinical Presentation
The most common clinical presentation of an adult WT flank pain, hematuria, abdominal mass or constitutional symptoms. Hypertension, which commonly occurs in pediatric WT has not been commonly reported in WT adult. While Kilton had described the 42% of patients have symptoms for more than a year before diagnosis, which has not been seen in other adult series. The tumors are often quite large on initial presentation. The varicocele may indicate an obstruction of the spermatic vein tumor thrombus secondary to renal vein or inferior vena cava. Acquired von Willebrand disease has been associated with pediatric WT proof is justified in adult patients with clinical bleeding tendency. CT scan of the chest and abdomen should be done before surgery to evaluate the metastasis and extrarenal WT. intravascular extension involving the renal vein and inferior vena cava can be seen. The most common sites of metastasis of WT are lung, lymph nodes and liver. The bone metastasis is rare and a bone scan or skeletal survey is warranted only in the presence of symptoms.
Its true incidence in adults is difficult to determine since it is included with renal cell carcinoma in the epidemiological reports, and varying diagnostic criteria used in case reports. Currently, most experts use the following criteria to define adult WT (I) primary renal neoplasm, (ii) blastematous primitive spindle or round cell component, (iii) formation of the tubular structure or glomeruloid abortion or embryonic, (iv) any area of the tumor diagnosis of CRC, (v) a graphic confirmation of the histology, and (vi) age> 15 years. Approximately 1.2% of pediatric weights have a family background; however, this has not been reported in adults.
Pathology
In contrast to childhood turbines, which are often multicentric and bilateral, most adult cases are unincentric WEIGHT with multicentric and bilateral disease in 7 and 5% of patients, respectively. Horseshoe kidneys are associated with twice the incidence of WT. The macroscopic and microscopic appearance of WT adult it tends to resemble a pediatric weight. WT gross appearance is variable and reflects the proportion of stromal components and nonstromal. WT generally is pale gray or cream and has a soft, however, the predominant stromal tumors can be white and firm. cyst formation may be important in certain cases.
WEIGHT contains variable proportions of undifferentiated blast cells and differentiated cells of epithelial and stromal lineage. Blast cells are undifferentiated, small, active mitosis, rounded or oval, and densely populated, with little cytoplasm. Can occur in several distinctive growth patterns within individual tumors, including diffuse, nodular, serpentine, and basaloid. WT epithelial component may appear as rosette-shaped primitive tubules and occasional glomeruloid structures.
heterologous epithelial differentiation squamous epithelial components, mucinous, or hair can be detected. The stromal component may have great diversity, but is usually composed of spindle cells with a myxoid background. heterologous elements including skeletal muscle, cartilage, bone, fat and neural tissue may be present. WT histological diversity is a hallmark. Characteristically, it has a triphasic pattern with components called blast, epithelial and stromal. Chemotherapy can alter the morphology by inducing the maturation of the elements blast, epithelial and stromal that leads to a disproportionate reduction of actively proliferating cells compared with the sample prechemotherapy. WEIGHT Metastatic may comprise a single element or a combination of what is present in the primary tumor. WT-1 antigen is usually identified in the blast and epithelial elements, but not in differentiated epithelial and stromal components.
nuclear anaplasia associated with an adverse outcome has been recognized in 5% of pediatric cases and the increase in prevalence with age and in certain populations (eg African Americans). Anaplasia requires the presence of multipolar mitotic figures, marked nuclear enlargement (three times higher than that of anaplastic nuclei) and nuclear hyperchromasia. The prognostic significance is deeper in the diffuse anaplasia compared with focal anaplasia. Large blast cells have also been identified as an adverse prognostic factor.
Nephrogenic rests are abnormally persistent foci of embryonic kidney tissue are capable of becoming WT. The presence of diffuse or multifocal nephrogenic rests is
defined as nephroblastomatosis. There are two variants of nephrogenic rests perilobular called nephrogenic rests (PLNR) and intralobar nephrogenic rests (ILNR). Can be seen in 25-45% of WT were pediatric and adult patients seen in WT as well as in several ectopic sites outside the kidney.
Pediatric weight has been associated with a number of known syndromes and genetic mutations. WAGR (Wilms tumor, aniridia, genitourinary anomalies, mental retardation) and Denys-Drash syndrome (gonadal dysgenesis, nephropathy early onset) syndromes associated with deletion or mutations of the WT1 gene (11p13), a gene critical for development renal and gonadal. The Beckwith-Wiedemann syndrome (hemihypertrophy, macroglossia, omphalocele, and organomegaly) is associated with loss of imprinting of WT2 (11p15). Due to lack of enough cases, genetics and syndromic associations have not been well elucidated in adults.
Clinical Presentation
The most common clinical presentation of an adult WT flank pain, hematuria, abdominal mass or constitutional symptoms. Hypertension, which commonly occurs in pediatric WT has not been commonly reported in WT adult. While Kilton had described the 42% of patients have symptoms for more than a year before diagnosis, which has not been seen in other adult series. The tumors are often quite large on initial presentation. The varicocele may indicate an obstruction of the spermatic vein tumor thrombus secondary to renal vein or inferior vena cava. Acquired von Willebrand disease has been associated with pediatric WT proof is justified in adult patients with clinical bleeding tendency. CT scan of the chest and abdomen should be done before surgery to evaluate the metastasis and extrarenal WT. intravascular extension involving the renal vein and inferior vena cava can be seen. The most common sites of metastasis of WT are lung, lymph nodes and liver. The bone metastasis is rare and a bone scan or skeletal survey is warranted only in the presence of symptoms.
The classification system used by the Children's Oncology Group (COG), Société International d'Oncology Paeditrique / International Society of Pediatric Oncology (SIOP) and the National Wilms Tumor Study Group (NWTSG) has been accepted by most WEIGHT authorities’ adults in the staging of WT. The staging is based on both radiological and surgical pathology. WT's forecast is worse in adults than children, possibly due to a constellation of factors, including frequent advanced stage disease at presentation, increased incidence of nuclear anaplasia, increased incidence of recurrence, poorer tolerance of aggressive treatment, and poorer response to treatment.
to be continued in Treatment and Prognosis Wilms Tumor ADULT kidney tumors
to be continued in Treatment and Prognosis Wilms Tumor ADULT kidney tumors