Patients typically present with a palpable abdominal mass, which may extend across the midline and down into the pelvis. Less often, the presenting features are fever and abdominal pain, hematuria or, occasionally, intestinal obstruction as a result of pressure from the tumor. The prognosis for Wilms tumor generally is very good, and excellent results are obtained with a combination of nephrectomy and chemotherapy. Anaplasia is a harbinger of adverse prognosis, but only if it is diffuse. If the anaplasia is focal and confined within the resected nephrectomy
Wilmstumoristhemostcommonrenalneoplasmofchildhood.
PatientswiththreesyndromesareatincreasedriskforWilmstumors:Denys-Drash,Beckwith-Wiedemann,andWilmstumor,aniridia,genitalabnormalities,andmentalretardation(WGAR)syndrome.
WAGRsyndromeandDDSareassociatedwithWT1inactivation,whereasBeckwith-WiedemannarisesthroughimprintingabnormalitiesattheWT2locus,principallyinvolvingtheIGF2 gene.
ThemorphologiccomponentsofWilmstumorincludeblastema(small,roundbluecells)andepithelialandstromalelements.
NephrogenicrestsareprecursorlesionsofWilmstumors.
specimen, the outcome is no different from that for tumors without evidence of anaplasia.
In the era predating the ready availability of molecular diagnostic assays, rendering the diagnosis of a genetic disorder depended on the identification of abnormal gene products (e.g., mutant hemoglobin or abnormal metabolites) or their clinical effects, such as mental retardation (e.g., in PKU). Several factors have since enabled the rapid expansion of molecular diagnostics from the realm of research to an almost ubiquitous presence in both academic and commercial pathology laboratories. These include (1) the sequencing of the human genome and the deposition of these data in publicly available databases; (2) the availability of numerous “off-the-shelf” polymerase chain
Fig.7.37 (A)Wilmstumorwithtightlypackedbluecellsconsistentwiththeblastemalcomponentandinterspersedprimitivetubules,representingtheepithelialcomponent.(B)FocalanaplasiawaspresentinotherareaswithinthisWilmstumor,characterizedbycellswithhyperchromatic,pleomorphicnuclei,andanabnormalmitosis(centeroffield).Predominanceofblastemalmorphologyanddiffuseanaplasiaareassociatedwithspecificmolecularlesions(seetext).
http://ebooksmedicine.net reaction (PCR) kits tailor-made for the identification of specific genetic disorders; (3) the availability of high-resolution microarrays (“gene chips”) that can interrogate both DNA and RNA on a genomewide scale using a single platform; and, finally, (4) the emergence of automated, high-throughput, next-generation (“NextGen”) sequencing technologies. The last two advances have been especially useful in the context of new research to elucidate the genetic basis for both mendelian and complex disorders. Although a detailed discussion of molecular diagnostics is beyond the scope of this book, some of the better-known approaches are highlighted in the ensuing paragraphs. Irrespective of the technique used, the genetic aberration being queried can be either in the germline (i.e., present in each and every cell of the affected person, as with a CFTR mutation in a patient with CF) or somatic (i.e., restricted to specific tissue types or lesions, as with MYCN amplification in neuroblastoma cells). This consideration determines the nature of the sample (e.g., peripheral blood lymphocytes [PBLs], saliva, tumor tissue) used for the assay.