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Ch10-Child - Diseases of Infancy& Childhood Diseases of...

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Unformatted text preview: Diseases of Infancy & Childhood Diseases of Infancy Diseases of Infancy and Childhood Congenital Anomalies Birth Weight and Gestational Age Birth Injuries Perinatal Infections Respiratory Distress Syndrome (RDS) Necrotizing Enterocolitis Intraventricular Hemorrhage Hydrops Inborn Metabolic/Genetic Errors Sudden Infant Death Syndrome (SIDS) Tumors INFANT MORTALITY INFANT MORTALITY USA 1970: 20 USA 2000: 7 USA WHITE: X USA BLACK: 2X SWEDEN 3 INDIA 82 Major Time Spans Major Time Spans Neonatal first period four weeks of life Infancy the Age first year of life 1 – 4 years (preschool) Age 5 – 14 years (school age) MORTALITY by TIME SPAN MORTALITY by TIME SPAN NEONATE (0-4 WEEKS): CONGENITAL, NEONATE PREMATURITY PREMATURITY UNDER ONE YEAR: CONGENITAL, PREMATURITY/WEIGHT, SIDS PREMATURITY/WEIGHT, 1-4 YEARS: ACCIDENTS, CONGENITAL, TUMORS TUMORS 5-14 YEARS: ACCIDENTS, TUMORS, HOMICIDES HOMICIDES 15-24 YEARS: ACCIDENTS, HOMICIDE, SUICIDE (NONE ARE “NATURAL” CAUSES) SUICIDE Cause of Death Related with Age Causes1 Rate 2 Under 1 Year: All 727.4 Causes 1–4 Years: All 32.6 Causes 5–14 Years: All 18.5 Causes 15–24 Years: All 80.7 Causes Rates are expressed per 100,000 population Excludes congenital heart disease 1 2 Congenital Anomalies Congenital Definitions Causes Pathogenesis • Malformations – primary errors of morphogenesis, usually multifactorial – e.g. congenital heart defect • Disruptions – secondary disruptions of previously normal organ or body region – e.g. amniotic bands • Deformations – extrinsic disturbance of development by biomechanical forces – e.g. uterine constraint • Sequence – a pattern of cascade anomalies explained by a single localized initiating event with secondary defects in other organs – e.g. Oligohydramnios (Or Potter) Sequence • Syndrome – a constellation of developmental abnormalities believed to be pathologically related – e.g Turner syndrome Malformations Polydactyly & syndactyly Cleft Lip Severe Lethal Malformation Disruption by an amniotic band Oligohydramnios (Or Potter) Sequence • Oligohydramnios (decreased amniotic fluid) – Renal agenesis – Amniotic leak • Fetal Compression – flattened facies – club foot (talipes equinovarus) • Pulmonary hypoplasia – fetal respiratory motions important for lung development • Breech Presentation The Oligohydramnios “Sequence” Infant with oligohydramnios sequence Organ Specific Anomalies • Agenesis: complete absence of an organ • Atresia: absence of an opening • Hypoplasia: incomplete development or under- development of an organ with decreased numbers of cells • Hyperplasia: overdevelopment of an organ associated with increased numbers of cells • Hypertrophy: increase in size with no change in number of cells • Dysplasia: in the context of malformations (versus neoplasia) describes an abnormal organization of cells Implantation and the Survival of Implantation and the Survival of Early Pregnancy Only 50-60% of all conceptions advance Only beyond 20 weeks beyond Implantation occurs at day 6-7 75% of loses are implantation failures and 75% are not recognized are Pregnancy loss after implantation is 25-40% NEJM 2001; 345:1400-1408 Approximate Frequency of the More Common Congenital “Malformations” in the United States Malformation Frequency per 10,000 Total Births Clubfoot without central nervous system anomalies 25.7 Patent ductus arteriosus 16.9 Ventricular septal defect 10.9 Cleft lip with or without cleft palate 9.1 Spina bifida without anencephalus 5.5 Congenital hydrocephalus without anencephalus 4.8 Anencephalus 3.9 Reduction deformity (musculoskeletal) 3.5 Rectal and intestinal atresia 3.4 Adapted from James LM: Maps of birth defects occurrence in the U.S., birth defects monitoring program (BDMP)/CPHA, 1970–1987. Teratology 48:551, 1993. #1 #2 #3 CAUSES OF ANOMALIES Genetic – karyotypic aberrations – single gene mutations • Environmental – infection – maternal disease – drugs and chemicals – irradiation • Multifactorial • Unknown Causes of Congenital Anomalies in Humans Frequency Cause (%) Genetic Chromosomal aberrations 10–15 Mendelian inheritance 2–10 Environmental Maternal/placental infections Maternal disease states Drugs and chemicals Irradiations Multifactorial (Multiple Genes ? Environment) Unknown 2–3 6–8 1 1 20–25 40–60 Adapted from Stevenson RE, et al (eds): Human Malformations and Related Anomalies. New York, Oxford University Press, 1993, p. 115. Embryonic Development Embryonic Development Embryonic period weeks 1- 8 of pregnancy organogenesis occurs in this period organogenesis Fetal period weeks 9 to 38 marked by further growth and maturation Critical Periods Of Development Genetic Causes Genetic Causes Karyotypic abnormalities 80-90% of fetuses with aneuploidy die in utero trisomy 21 (Down syndrome) most common trisomy karyotypic abnormality (21,18,13) karyotypic sex chromosome abnormalities next most sex common (Turner and Klinefelter) common autosomal chromosomal deletion usually lethal karyotyping frequently done with aborted karyotyping fetuses with repeated abortions fetuses Single gene mutations covered in separate chapters Maternal Viral Infection • Rubella (German measles) – at risk period first 16 weeks gestation – defects in lens (cataracts), heart, and CNS (deafness and mental retardation) – rubella immune status important part of prenatal workup • Cytomegalovirus – most common fetal infection – highest at risk period is second trimester – central nervous system infection predominates Drugs and Chemicals Drugs and Chemicals Drugs 13 cis-retinoic acid (acne agent) warfarin angiotensin converting enzyme inhibitors angiotensin (ACEI) (ACEI) anticonvulsants oral diabetic agents thalidomide Alcohol Tobacco Tobacco Teratogen Actions Teratogen Actions • Proper cell migration to predetermined locations that cell influence the development of other structures • Cell proliferation, which determines the size and form of Cell which embryonic organs • Cellular interactions among tissues derived from Cellular different structures (e.g., ectoderm, mesoderm), which affect the differentiation of one or both of these tissues • Cell-matrix associations, which affect growth and Cell-matrix which differentiation • Programmed cell death (apoptosis), which, as we have Programmed which, seen, allows orderly organization of tissues and organs during embryogenesis • Hormonal influences and mechanical forces, which Hormonal mechanical which affect morphogenesis at many levels affect Diabetes Mellitus Diabetes Mellitus Fetal Macrosomy (>10 pounds) maternal hyperglycemia increases insulin maternal secretion by fetal pancreas, insulin acts with growth hormone effects growth Diabetic Embryopathy most crucial period is immediately post most fertilization fertilization malformations increased 4-10 fold with malformations uncontrolled diabetes, involving heart and CNS uncontrolled Oral agents not approved in pregnancy Diabetics attempting to conceive should be Diabetics placed on insulin placed Birth Weight and Gestational Birth Weight and Gestational Age Appropriate for gestational age (AGA) between 10 and 90th percentile for gestational age Small for gestational age (SGA) , <10% Large for gestational age (LGA) , >90% Preterm born before 37 weeks (<2500 grams) born 37 Post-Term delivered after 42 weeks delivered 42 Prematurity Prematurity Defined as gestational age < Defined 37 weeks weeks Second most common cause of neonatal Second mortality (after congenital anomalies) mortality Risk factors for prematurity Preterm Premature Rupture Of fetal Preterm remature upture fetal Membranes (PPROM) Intrauterine infection Uterine, cervical, and placental abnormalities Multiple gestation Fetal Growth Restriction Fetal Growth Restriction At least 1/3 of infants born at term are < 2.5kg Undergrown rather than immature Commonly underlies SGA (small for gestational Commonly SGA age) age) Prenatal diagnosis: ultrasound measurements Classification Fetal Placental Maternal Fetal FGR Fetal FGR Chromosomal abnormalities 17% of FGR overall up to 66% of fetuses with ultrasound up malformations malformations Fetal Infection Infection: TORCH (Toxoplasmosis, Other, oxoplasmosis, ther, Rubella, Cytomegalovirus, Herpes) ubella, ytomegalovirus, Characterized by symmetric growth Characterized restriction – head and trunk proportionally involved involved Placental FGR Placental FGR Vascular umbilical cord anomalies (single artery, umbilical constrictions, etc) constrictions, thrombosis and infarction multiple gestation Confined placental mosaicism mutation in trophoblast trisomy is common Placental FGR tends to cause Placental asymmetric growth with relative sparing of the head Maternal FGR Maternal FGR Most common cause of FGR by far Vascular diseases preeclampsia (toxemia of pregnancy) hypertension Toxins ethanol narcotics and cocaine heavy smoking Organ Immaturity Organ Immaturity Lungs alveoli differentiate in 7th month surfactant deficiency Kidneys glomerular differentiation is incomplete Brain impaired homeostasis of temperature vasomotor control unstable Liver inability to conjugate and excrete bilirubin APGAR (Appearance, Pulse, Grimace, Activity, Respiration) Evaluation Of The Newborn Infant Sign Heart rate Respiratory effort Muscle tone 0 Absent Absent 1 Below 100 Slow, irregular Limp Response to catheter in nostril (tested after oropharynx is clear) Color No response Some flexion of Active motion extremities Grimace Cough or sneeze Blue, pale 2 Over 100 Good, crying Body pink, Completely extremities blue pink Data from Apgar V: A proposal for a new method of evaluation of the newborn infant. Anesth Analg 32:260, 1953. Apgar Score and 28 Day Apgar Score and 28 Day Mortality Score Score may be evaluated at 1 and 5 minutes minutes 5 minute scores 0-1, 50% mortality 4, 20% mortality ≥ 7, nearly 0% mortality 7, Perinatal Infection • Transcervical (ascending) – inhalation of infected amniotic fluid • pneumonia, sepsis, meningitis • commonly occurs with PROM – passage through infected birth canal • herpes virus– caesarian section for active herpes • Transplacental (hematogenous) – mostly viral and parasitic • HIV—at delivery with maternal to fetal transfusion • TORCH • parvovirus B19 (Fifth), erythema infectiosum – bacterial • Listeria monocytogenes Fetal Lung Maturation Neonatal Respiratory Distress Syndrome (RDS) • 60,000 cases / year in USA with 5000 deaths • Incidence is inversely proportional to gestational age • The cause is lung immaturity with decreased alveolar surfactant – surfactant decreases surface tension – first breath is the hardest since lungs must be expanded – without surfactant, lungs collapse with each breath RDS Risk Factors RDS Risk Factors 1) Prematurity by far the greatest risk factor affected infants are nearly always premature 2) Maternal diabetes mellitus insulin suppresses surfactant secretion 3) Cesarean delivery normal delivery process stimulates surfactant normal secretion secretion RDS Pathology RDS Pathology Gross solid and airless (no crepitance) sink in water appearance is similar to liver tissue* Microscopic atelectasis and dilation of alveoli hyaline membranes composed of fibrin and hyaline cell debris line alveoli (HMD former name) cell minimal inflammation V/Q Mismatch RDS Prevention and Treatment RDS Prevention and Treatment Delay labor until fetal lung is mature amniotic fluid phospholipid levels are useful in amniotic assessing fetal lung maturity assessing Induce fetal lung maturation with antenatal Induce corticosteriods corticosteriods Postnatal surfactant replacement therapy Postnatal with oxygen and ventilator support with Treatment Complications Treatment Complications Oxygen toxicity Retrolental fibroplasia hypoxia causes ↑ Vascular Endothelial Growth Factor hypoxia ascular ndothelial rowth actor oxygen derived free radicals damage tissue (VEGF) and angiogenesis Oxygen Rx suppresses VEGF and causes endothelial Oxygen apoptosis apoptosis Bronchopulmonary “dysplasia” oxygen suppresses lung septation at the saccular stage mechanical ventilation epithelial hyperplasia, squamous metaplasia, and peribronchial epithelial and interstitial fibrosis were seen with old regimens of ventilator usage and no surfactant use, but are now uncommon usage lung septation is still impaired Necrotizing Enterocolitis Necrotizing Enterocolitis Incidence is directly proportional to Incidence prematurity, like RDS prematurity, approaches 10% with severe prematurity 2000 cases yearly in USA Pathogenesis not fully understood intestinal ischemia inflammatory mediators breakdown of mucosal barrier Necrotizing Enterocolitis Hydrops Fetalis Hydrops Fetalis Chromosomal abnormalities Turner syndrome with cystic hygromas other Cardiovascular with heart failure anemia with high output failure immune hemolytic anemia hereditary hemolytic anemia (α-thalassemia) parvovirus B19 infection twin to twin in utero transfusion congenital heart defects Hydrops Fetalis Immune Hydrops Immune Hydrops Fetus inherits red cell antigens from the Fetus father that are foreign to the mother father Mother forms IgG antibodies which cross Mother the placenta and destroy fetal RBCs the Fetus develops severe anemia with CHF Fetus and compensatory ↑ hematopoiesis (frequently extramedullary) (frequently Most cases involve Rh D antigen mother is Rh Neg and fetus is Rh Pos Neg ABO and other antigens involved less often Pathogenesis of Sensitization Pathogenesis of Sensitization Fetal RBCs gain access to maternal Fetal circulation largely at delivery or upon abortion abortion Since IgM antibodies are involved in Since primary response and prior sensitization is necessary, the first pregnancy is not usually affected usually Maternal sensitization can be prevented in Maternal most cases with Rh immune globulin (Rhogam) given at time of delivery or abortion (spontaneous or induced) abortion Treatment of Immune Hydrops Treatment of Immune Hydrops In utero iidentification of at risk infants via blood typing dentification by amniocentesis, (Chorionic Viilli Sampling) by horionic lli ampling) CVS, or fetal blood sampling CVS, fetal transfusions via umbilical cord early delivery Live born infant monitoring of hemoglobin and bilirubin exchange transfusions Kernicterus Pathogenesis of Immune Hydrops Inborn Errors of Metabolism Inborn Errors of Metabolism (Genetic) PhenylKetonUria (PKU) Galactosemia Cystic Fibrosis (CF) ystic (Mucoviscidosis) (Mucoviscidosis) PHENYLKETONURIA (PKU) • Ethnic distribution – common in persons of Scandinavian descent – uncommon in persons of African-American and Jewish descent • Autosomal recessive • Phenylalanine hydroxylase deficiency leads to hyperphenylalaninemia, brain damage, and mental retardation • Phenylananine metabolites are excreted in the urine • Treatment is phenylalanine restriction • Variant forms exist GALACTOSEMIA • Autosomal recessive • Lactose → glucose + galactose • Galactose-1-phosphate uridyl transferase (GALT) – GALT is involved in the first step in the transformation of galactose to glucose – absence of GALT activity → galactosemia • Symptoms appear with milk ingestion – liver (fatty change and fibrosis), lens of eye (cataracts), and brain damage involved (mechanism unknown) • Diagnosis suggested by reducing sugar in urine and confirmed by GALT assay in tissue • Treatment is removal of galactose from diet for at least the two first years of life Cystic Fibrosis Cystic Fibrosis Normal Gene Mutational Spectra Genetic/Environmental Modifiers Morphology Clinical Course Cystic Fibrosis (Mucoviscidosis) Cystic Fibrosis (Mucoviscidosis) Autosomal recessive Most common lethal genetic disease Most affecting Caucasians (1 in 3,200 live births in the USA) in 2-4% of population are carriers Uncommon in Asians and African-Americans Uncommon Widespread disorder in epithelial chloride Widespread transport affecting fluid secretion in exocrine glands epithelial lining of the respiratory, epithelial gastrointestinal, and reproductive tracts gastrointestinal, Abnormally viscid mucus secretions Cellular Metabolism Of The Cystic Fibrosis Transmembrane Regulator (CFTR) Harrison’s Internal Med, 16th Ed CFTR Gene: Normal CFTR Gene: Normal Cystic Fiibrosis Transmembrane Conductance ystic brosis ransmembrane Regulator (CFTR) CTFR → epithelial chloride channel protein Sweat gland agonist induced regulation of the chloride channel interacts with epithelial sodium channels (ENaC) CTFR activation increases luminal Cl− resorption resorption ENaC increases Na+ resorption sweat is hypotonic Respiratory and Intestinal epithelium CTFR activation increases active luminal secretion of CTFR chloride chloride ENaC is inhibited CFTR Gene: Cystic Fibrosis CFTR Gene: Cystic Fibrosis Sweat gland CTFR absence decreases luminal Cl− resorption resorption ENaC decreases Na+ resorption sweat is hypertonic Respiratory and Intestinal epithelium CTFR absence decreases active luminal secretion of CTFR chloride chloride llack of inhibition of ENaC is opens sodium channel with ack active resorption of luminal sodium active secretions are decreased but isotonic Chloride Channel Defect and Effects CFTR Gene: Mutational Spectra CFTR Gene: Mutational Spectra More than 800 mutations are known These are grouped into six classes mild to severe Phenotype is correlated with the Phenotype combination of these alleles combination correlation is best for pancreatic disease genotype-phenotype correlations are less genotype-phenotype consistent with pulmonary disease consistent Other genes and environment further Other modify expression of CFTR modify Clinical Manifestations Of Mutations In The Cystic Fibrosis Gene Organ Pathology Organ Pathology Plugging of ducts with viscous mucus and loss of Plugging ciliary function of respiratory mucosa ciliary Pancreas Liver plugging of bile canaliculi with portal inflamation biliary cirrhosis may develop Genitalia atrophy of exocrine pancreas with fibrosis islets are not affected Absence of vas deferens and azoospermia Sweat glands normal histology Lung Pathology in CF • More than 95% of CF patients die of complications resulting from lung infection • Viscous bronchial mucus with obstruction and secondary infection – S. aureus – Pseudomonas – Hemophilus • Bronchiectasis – dilatation of bronchial lumina – scarring of bronchial wall Cystic Fibrosis Clinical Manifestations CF Diagnosis CF Diagnosis Clinical criteria sinopulmonary gastrointestinal pancreatic intestinal salt loss male genital tract Sweat chloride analysis Nasal transepithelial potential difference DNA Analysis gene sequencing gene Clinical Course and Treatment Clinical Course and Treatment Highly variable – median life expectance is Highly 30 years 30 7% of patients in the United States are 7% diagnosed as adults Clearing of pulmonary secretions and Clearing treatment of pulmonary infection treatment Transplantation lung liver-pancreas Sudden Infant Death Syndrome (SIDS) Epidemiology Morphology Pathogenesis Sudden Infant Death Syndrome Sudden Infant Death Syndrome NIH Definition sudden death of an infant under 1 year of age sudden which remains unexplained after a thorough case investigation, including performance of a complete autopsy, examination of the death scene, and review of the clinical history scene, Crib death another name based on the fact that most die another in their sleep in Epidemology of SIDS Epidemology of SIDS Leading cause of death in USA of infants Leading between 1 month and 1 year of age between 90% of deaths occur ≤ 6 months age, 90% mostly between 2 and 4 months mostly In USA 2,600 deaths in 1999 (down from In 5,000 in 1990) 5,000 Risk Factors for SIDS • • • Parental – Young maternal age (age <20 years) – Maternal smoking during pregnancy – Drug abuse in either parent, specifically paternal marijuana and maternal opiate, cocaine use – Short intergestational intervals – Late or no prenatal care – Low socioeconomic group – African American and American Indian ethnicity (? socioeconomic factors) Infant – Brain stem abnormalities, associated defective arousal, and cardiorespiratory control – Prematurity and/or low birth weight – Male sex – Product of a multiple birth – SIDS in a prior sibling – Antecedent respiratory infections Environment – Prone sleep position – Sleeping on a soft surface – Hyperthermia – Postnatal passive smoking Morphology of SIDS Morphology of SIDS exclusion exclusion SIDS is a diagnosis of SIDS Non-specific autopsy findings Multiple petechiae Multiple Pulmonary congestion ± pulmonary edema These may simply be agonal changes as they These are found in non-SIDS deaths also are Subtle changes in brain stem neurons Autopsy typically reveals no clear cause of Autopsy death death Pathogenesis of SIDS Pathogenesis of SIDS Generally accepted to be multifactorial Triple risk model Vulnerable infant Critical development period in homeostatic Critical control control Exogenous stressors Brain stem abnormalities, associated Brain defective arousal, and cardio-respiratory control control Prevention of SIDS Prevention of SIDS Maternal factors attention to risk factors previously mentioned redress problems in medical care for underprivileged Environmental avoid prone sleeping Avoid sleeping on soft surfaces back to sleep program: infant should sleep in supine position no pillows, comforters, quilts, sheepskins, and stuffed toys no Sleeping clothing (such as a sleep sack) may be used in Sleeping place of blankets. Avoid hyperthermia no excessive blankets set thermostat to appropriate temperature avoid space heaters Diagnosis of SIDS Diagnosis of SIDS exclusion exclusion SIDS is a diagnosis of SIDS Complete autopsy Examination of the death scene Review of the clinical history Differential diagnosis child abuse intentional suffocation TUMORS TUMORS Benign Malignant BENIGN BENIGN Hemangiomas Lymphatic Tumors Fibrous Tumors Teratomas (also can be Teratomas malignant) malignant) Hemangioma Hemangioma Benign tumor of blood vessels Are the most common tumor of infancy Usually on skin, especially face and scalp Regress spontaneously in many cases Congenital Capillary Hemangioma At birth At 2 years After spontaneous regression Teratomas Teratomas Composed of cells derived from more than Composed one germ layer, usually all three one Sacrococcygeal teratomas most common childhood teratoma frequency 1:20,000 to 1:40,000 live births 4 times more common in boys than girls Aproximately 12% are malignant often composed of immature tissue occur in older children Sacrococcygeal Teratoma MALIGNANT MALIGNANT Neuroblastic Tumors Wilms Tumor Incidence and Types TABLE 10-9 -- Common Malignant Neoplasms of Infancy and Childhood 0 to 4 Years 5 to 9 Years Leukemia Leukemia Retinoblastoma Retinoblastoma Neuroblastoma 10 to 14 Years Neuroblastoma Wilms tumor Hepatoblastoma Hepatocarcinoma Soft tissue sarcoma (especially Soft tissue sarcoma rhabdomyosarcoma) Hepatocarcinoma Soft tissue sarcoma Teratomas Central nervous system tumors Central nervous system tumors Ewing sarcoma Lymphoma Osteogenic sarcoma Thyroid carcinoma Hodgkin disease Round Blue Small Cell Tumors Small Frequent in pediatric tumors Differential diagnosis Lymphoma Neuroblastoma Wilms tumor Rhabdomyosarcoma Ewings tumor Diagnostic procedures immunoperoxidase stains electron microscopy chromosomal analysis and molecular markers Neuroblastomas Neuroblastomas Second most common malignancy of Second childhood (650 cases / year in USA) childhood Neural crest origin adrenal gland – 40 % sympathetic ganglia – 60% In contrast to retinoblastoma, most are In sporadic but familiar forms do occur sporadic Median age at diagnosis is 22 months Neuorblastoma Morphology Neuorblastoma Morphology Small round blue cell tumor neuorpil formation rosette formation immunochemistry – neuron specific enolase EM – secretory granules (catecholamine) Usual features of anaplasia high mitotic rate is unfavorable evidence of Schwann cell or ganglion evidence differentiation favorable differentiation Other prognostic predictors are used by Other pathologists and oncologists pathologists Neuorblastoma ** * *Neuropil **Homer-Wright Rosettes Clinical Course and Prognosis Clinical Course and Prognosis Hematogenous and lymphatic metastases to liver, Hematogenous lungs and bone lungs 90% produce catecholamines, but hypertension is 90% uncommon uncommon Age and stage are most important prognostically Amplification of N-myc oncogene < 1 year age: good prognosis regardless of stage present in 25-30% of cases and is unfavorable up to 300 copies on N-myc has been observed Risk Stratification low risk: 90% cure rate high risk 20% cure rate Wilms Tumor Wilms Tumor Most common primary renal tumor of Most childhood childhood Incidence 10 per million children < 15 years Usually diagnosed between age 2-5 5 – 10 % are multi-focal, i.e., bilateral synchronous metachronous Clinical Features Clinical Features Most children present with a large Most abdominal mass abdominal Treatment nephrectomy and combination chemotherapy two two year survival up to 90% even with spread beyond the kidney beyond Pathogenesis of Wilms Tumor Pathogenesis of Wilms Tumor 10% of Wilms tumors arise in one of three 10% congenital malformation syndromes with distinct chromosomal loci distinct Familial disposition for Wilms is rare, and most Familial of these patients have de novo mutations de Nephrogenic rests of adjacent parenchyma present in 40% of unilateral tumors, 100% of present bilateral tumors bilateral if found in one kidney, these rests predict an if increased risk for tumor in the contralateral kidney kidney Pathology of Wilms Tumor Pathology of Wilms Tumor Gross well circumscribed fleshy tan tumor areas of hemorrhage and necrosis Microscopic: triphasic appearance Blastema: small blue cells Epithelial elements: tubules & glomeruli Stromal elements Anaplasia correlates with p53 mutation and poor correlates prognosis and resistance to chemotherapy prognosis Wilms Tumor ...
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