Path Pediatric Disorders

Front 1

Malformation

Back 1

primary error of morphogenesis, intrinsic abnormality of the developmental process, multifactorial ex: congenital heart disease

Front 2

Distruption

Back 2

destruction of an organ following normal development of that organ, due to an extrinsic disturbance, can be caused by an environmental agent, nonheretible, not a 1° developmental problem.

Front 3

Deformation

Back 3

Localized or generalized compression of the growing fetus by abnormal force, ex: uterine constraint, not a 1° developmental problem

Front 4

Sequence

Back 4

multiple congenital anomalities resuling as 2° effects of a single, localized aberration in organogenesis. Ex: oligohydramnios sequence - ⇓ amniotic fluid causes many abnormalities of the infant

Front 5

Syndrome

Back 5

= presence of several defects that cannot be explained on the basis of a single initiating error

Front 6

o transplacenal spread of infection
what it is
examples

Back 6

crosses the placenta via chorionic villi, may happen at any time during gestation; TORCH – Toxoplasma, Other, Rubella, Cytomegalovirus, Herpes virus

Front 7

timing of fetal maturation

Back 7

- 1st 3 weeks of pregnancy – if an injurous agent occurs, baby will abort if there is a lot of damage or will recover fully if there is not enough damage to abort
- 3-9 weeks – embryo is extremely susceptible to teratogenesis – peak of sensitivity – btw 4th and 5th weeks, when organs are being made
- after 9 weeks = fetal period, in which the feus is susceptible to growth retardation or injury to already forme organs
- same teratogen can have different effects at different times

Front 8

premature infants are at higher risk for:

Back 8

- respiratory distress syndrome
- necrotizing enterocolitis
- intraventricular and germinal matric hemorrhage

Front 9

fetal growth restriction

Back 9

preterm infants have low birth weights, but when adjusted for their age, their weight is appropriate, unlike infants w/ fetal growth restriction; causes:
- fetal factors: chromosomal disorders, congenital abnormalities, fetal infections; when the causation is in the fetus, growth retardation is symmetrical (affects all organ systems equally)
- placental factors: low placental implantation, placenta seperates, placental infarction; asymmetric growth retardation
- maternal factors: vascular diseases (preeclampsia), chronic hypertension, narcotic use, alcohol intake, cig smoking, maternal malnutrition; asymmetric growth retardation

Front 10

RESPIRATORY DISTRESS SYNDROME

Back 10

- 1/24,000 infants
- mainly seen w/ premature infants, immature lung is unable to produce surfactant
- also seen w/ maternal diabetes - hyperinsulinemia can suppress surfactant production
- corticosteroids ⇑ surfactant production, released in labor, so also seen in c sections performed before labor
- surfactant is needed to ⇓ surface tension and keep alveoli open
- morphology: alveoli collapse, lung is airless, eosinophilic hyaline membranes line bronchioles w. necrotic epithelial cells and plasma proteins/ fibrin
- clinical: in premature infants, prophylactic administration of surfactant, O2 is required, prophylactic glucocorticoid therapy
- O2 administration can cause retrolental fibroplasia, bronchopulmonary dysplasia

Front 11

NECROTIZING ENTEROCOLITIS

Back 11

- 1/10 births under 1500 mg
- premature infant disease
- need intestinal ischemia, may be due to selective reduction in intestinal blood flow (favoring vital organs) or generalized hypoperfusion
- predisposition: bacterial colonization, formula feeds
- occurs in terminal ileum, cecum, or rt colon
- involved segment is distended, friable, congested, submucosal gas bubbles, coagulative necrosis, ulceration
- clinical: bloody stools, abdominal distention, gas in intestinal wall

Front 12

SUDDEN INFANT DEATH SYNDROME

Back 12

- sudden death of an infant under 1 yr of age which is unexplained after investigation
- baby dies while asleep, during “critical developmental period” ie btw 1 mo and a year
- infant has some sort of maldevelopment or delay in the area causing arousal and cardiorespiratory control
- ⇑ risk w/ prone (stomach) sleeping, sleeping on soft surfaces, thermal stress
- see multiple petechiae, lungs congested /w vascular engorgement

Front 13

FETAL HYDROPS

Back 13

= accumulation of edema fluid in fetus
immune hydrops – blood group incompatibility btw mom and baby (usually Rh group) causes Abs to form →hemolytic anemia→ tissue ischemia, intrauterine heart failure →edema
- IgM can’t cross the placenta, so Rh disease isn’t usually seen in 1st pregnancy
- Give anti Dglobin after delivery (when mom might be exposed to baby’s blood) and prevent mom from being sensitized and making Abs, so next pregnancy, mom won’t have any Abs agst baby either
- ⇑ circulating bilirubin
Nonimmune
Causes: cardiovascular defects, chromosomal abnormalities, anemia (can be caused by parvovirus B19, thalessmia)
2° to all of these disorders is heart failure which can lead to edema

most severe form of hydrops = hydrops fetalis; dysmorphic features suggest underlying chromosomal abnormalities; 2° to cardiac failure are enlarged liver and spleen; due to heart failure, there is compensatory hyperplasia of erythroid precursors in the bone marrow, and there extramedullary hematopoesis occurring in liver and spleen – this causes erythroblastosis fetalis (= increase in immature RBCs) (exception: parvovirus which causes the arrest of erythroblast precurors in the BM from maturing)

Front 14

CYSTIC FIBROSIS

Back 14

- 1/3200, most common lethal genetic disease affecting Caucasians, autosomal recessive
- abnormal epithelial Cl- channel, transport disorder in which epithelial membranes are impermeable to Cl- ions
- ⇓H2O content of fluids coating the respiratory and intestinal epithelium
- → dehydration in lungs causes defective mucociliary function → repeated infection, usually cause of death
- →can have SI obstruction in infants = meconium ileus
- viscous secretions in pancreatic ducts plug the pancreas, causing atrophy of the glands & pancreatic insufficiency → malabsorption of protein, fat, fat soluble vitamins - ⇓ vit A, D, K (severe form of disease); in mild form of disease – pancreatic sufficient, have normal growth
- ⇑ NaCl in sweat
- due to a deletion at AA position 508
- infertility in males
- bile duct may be plugged by mucus → hepatic steatosis, cirrhosis

Front 15

- hemangiomas

Back 15

– area of elevated or flat skin, usually on face or scalp that is composed of irregular red or blue masses, usually spontabeoulsy regresses

Front 16

- lymphangiomas

Back 16

cystic, cavernous spaces surrounded by lymph aggregates on skin, neck, axilla, mediastinum, retroperitineum

Front 17

- sacrococcygeal teratoma

Back 17

most common germ cell tumor of childhood; sometimes seen w/ other congential abnormalities, most are benign
looks like baby is sitting on a ball

Front 18

NEUROBLASTOMA
- how do they present
-where
- prognosis/ what makes it better or worse

Back 18

- tumors arising in the adrenal medulla or the sympathetic ganglia derived from the primordial neural crest cells
- many spontaneously regress, or have spontanesous or therapy induced maturation, leaving a focus of calcification in adult
- morphology: small, primitive appearing cells w/ dark nuclei, scant cytoplasm, poorly defined cell borders growing in solid sheets, background is faintly eopsinophilic, rosettes (=homerwright pseudo rosettes) can be found in which the tumor cells are concentrically arranged about a central space filled w/ neutrophil
- prognosis: depents on the stage of the tumor and age of the patient – lower stage w/o mets usually better, except stage 4S which has mets but still has a very good prognosis; pts under 1yr have a better prognosis; amplifications of MYCN oncogene indicate a poor prognosis, more amplifications – worse prognosis.
- Pts under 2 present w/ abdominal mass, fever, weight loss; older children may not present until mets cause hepatomegaly, ascites, and bone pain; in neonates – neuroblastomas may present w/ multiple cutaneous mets w/ deep blue discoloration of the skin
- These tumors often produce catecholamines, ⇑ blood levels impt in d/x

Front 19

RETINOBLASTOMA

Back 19

- congenital tumor, familial cases develop multiple tumors that are bilateral, these pts are also at ⇑risk of developing osteosarcoma and other soft tissue tumors
- seen w/ mutation in RB1 gene, tumors arise from a cell of neuroepithelial origin, usually in the posterior retina
- pt presents~2 yrs of age, poor vision, strabismus, whitish hue to pupil, pain and tenderness in eye
- if untreated, could be fatal, can be t/x w/ chemo – good prognosis, may regress on their own; most common mets are to the CNS, skull, distal bones, lymph nodes
- morphology: tumors usually nodular masses, small round cells w/ large hyperchromic nuclei and scant cytoplasm, can see Flexner wintersteiner rosettes of cuboidal cells arranger around a central lumen

Front 20

WILMS’ TUMOR

Back 20

- most common 1° tumor of the kidney in children, btw 2-5 yrs
- associated w/ congenital malformations:
o people w/ WAGR syndrome (genital abnormalities, mental retardation) have ⇑⇑ risk of wilm’s tumor
o DenysDrash syndrome (gonadal dysgenesis and renal abnormalities) have ⇑⇑risk of wilm’s tumor
→ both of these conditions are associated w/ abnormalities of wilms tumor gene 1 (WT1) on chromosome 11, this gene is critical to normal renal and gonadal dvmpt
o Beckwith-wiedemann syndrome (BWS) (enlarded body organs, enlarged adrenal cortical risk of wilms tumor, this disease is a disorder of genetic imprinting, this affects the WT2 locus
o Congenital malformations and tumors represent related manifestations of genetic damaged affecting 1 gene or closely linked genes
- Morphology: stromal component – spindle shaped cells, less cellular area, epithelial component – immature tubule, blastemal component - tightly packed blue cells
- Clinical: palpable abdominal mass, t/x w/ nephrectomy and chemo, good prognosis; worst prognosis is for those w/ diffuse anaplasia w/ extra renal spread