Cut section showing two halves of a nephroblastoma specimen. Note the prominent septa subdividing the sectioned surface and the protrusion of tumor into the renal pelvis, resembling botryoid rhabdomyosarcoma. Low magnification micrograph showing the characteristic triphasic pattern consisting of tubules, solid sheets of small round cells, and stroma. H&E stain. Wilms' tumor has many causes, which can broadly be categorized as syndromic and non-syndromic. Syndromic causes of Wilms' tumor occur as a result of alterations to genes such as the Wilms Tumor 1 (WT1) or Wilms Tumor 2 (WT2) genes, and the tumor presents with a group of other signs and symptoms. Non-syndromic Wilms' tumor is not associated with other symptoms or pathologies. Many, but not all, cases of Wilms' tumor develop from nephrogenic rests, which are fragments of tissue in or around the kidney that develop before birth and become<unk> ous after birth. In particular, cases of bilateral Wilms' tumor, as well as cases of Wilms' tumor derived from certain genetic syndromes such as Denys-Drash syndrome, are strongly associated with nephrogenic rests. Most nephroblastomas are on one side of the body only and are found on both sides in less than 5% of cases, although people with Denys-Drash syndrome mostly have bilateral or multiple tumors. They tend to be encapsulated and vascularized tumors that do not cross the midline of the abdomen. In cases of metastasis it is usually to the lung. A rupture of Wilms' tumor puts the patient at risk of bleeding and peritoneal dissemination of the tumor. In such cases, surgical intervention by a surgeon who is experienced in the removal of such a fragile tumor is imperative. Pathologically, a triphasic nephroblastoma comprises three elements: * blastema * mesenchyme (stroma) * epithelium Wilms' tumor is a malignant tumor containing metanephric blastema, stromal and epithelial derivatives. Characteristic is the presence of abortive tubules and glomeruli surrounded by a spindled cell stroma. The stroma may include striated muscle, cartilage, bone, fat tissue, and fibrous tissue. Dysfunction is caused when the tumor compresses the normal kidney parenchyma. The mesenchymal component may include cells showing rhabdomyoid differentiation or malignancy (rhabdomyosarcomatous Wilms). Wilms' tumors may be separated into two prognostic groups based on pathologic characteristics: * Favorable – Contains well developed components mentioned above * Anaplastic – Contains diffuse anaplasia (poorly developed cells) Molecular biology and related conditions Mutations of the WT1 gene which is located on the short arm of chromosome 11 (11p13) are observed in approximately 20% of Wilms' tumors, the majority of them being inherited from the germline, while a minority are acquired somatic mutations. In addition at least half of the Wilms' tumors with mutations in WT1 also carry acquired somatic mutations in CTNNB1, the gene encoding the proto-oncogene beta-catenin. This latter gene is found on short arm of chromosome 3 (3p22.1). Most cases do not have mutations in any of these genes. Syndrome Name Associated Genetic Variant Risk for Wilms tumor Description of Syndrome WAGR syndrome (Wilms tumor, aniridia, genital anomalies, retardation) Gene deletion that includes both WT1 and PAX6 45–60% Characterized by Wilms tumor, aniridia (absence of iris), hemihypertrophy (one side of body larger than the other), genitourinary abnormalities, ambiguous genitalia, intellectual disability. Denys-Drash syndrome (DDS) WT1 (exon 8 and 9) 74% Characterized by kidney diseases since birth leading to early-onset kidney failure, ambiguous genitalia (intersex disorders). Beckwith-Wiedemann Syndrome Abnormal regulation of chromosome 11p15.5 7% Characterized by macrosmia (large birth size), macroglossia (large tongue), hemihypertrophy (one side of the body is larger), other tumors in body, omphalocele (open abdominal wall) and visceromegaly (enlargement of organs inside abdomen). An association with H19 has been reported. H19 is a long noncoding RNA located on the short arm of chromosome 11 (11p15.5).
types of Kidney cancer
symptom of Kidney cancer
types of Bladder cancer
medical cause of Chronic kidney disease
complications of Kidney disease
medical cause of Neoplasm
types of Lung cancer
complications of Cirrhosis