Pediatric Pathology Flashcards
(164 cards)
1
Q
Define malformation
A
Primary error of morphogenesis (intrinsic abnormal developmental process)
2
Q
Examples of malformation
A
Syndactyly
Polydactyly
Cleft lip
Cleft palate
Congenital heart disease
3
Q
Define disruption
A
Secondary destruction of a previously normal organ or body region
4
Q
Example of disruption
A
Amniotic bands
5
Q
Define deformation
A
Structural anomalies secondary to abnormal mechanical forces
6
Q
Examples of deformation
A
Clubfoot due to bicornuate uterus
Oligohydramnios
7
Q
Define sequence
A
Cascade of anomalies triggered by 1 initiating aberration
8
Q
Describe Potter sequence
A
Chronic oligohydramnios causes:
1. Flattened facies with compressed nose and low set ears
2. Small chest circumference (pulmonary hypoplasia)
3. Clubfeet
4. Hip dislocation
9
Q
Most common cause of death in Potter sequence
A
Pulmonary hypoplasia
10
Q
Characteristic placental finding in oligohydramnios
A
Amnion nodosum
11
Q
Define malformation syndrome
A
Constellation of congenital anomalies believed to be pathologically related that cannot be explained on the basis of a single, localized, initiating effect
12
Q
Common causes of a large placenta
A
- Twin pregnancy
- Maternal DM
- Chronic intrauterine infections
- Severe maternal or fetal anemia
- Rh incompatibility
- Heavy smoking
- Placental chorangiomas
13
Q
Common causes of a small placenta
A
- IUGR
- Chromosomal abnormalities
- Intrauterine infection
- Pre-eclampsia
14
Q
Mechanisms of microorganism transmission via cervicovaginal route
A
- Infected birth canal
- Inhaling infected amniotic fluid
15
Q
Infections associated with plasma cells in placenta
A
- CMV
- Syphilis
16
Q
List chronologic sequence of ascending infection
A
- Involving only free membranes near cervical os
- Subchorionic intervillositis
- Chorionitis
- Chorioamnionitis
- With funisitis
17
Q
Type of placenta associated with twin-twin transfusion
A
Monochorionic
18
Q
Type of placenta associated with monozygotic twins
A
Monochorionic
19
Q
Clinical significance of velamentous cord insertion
A
Tearing during labor and delivery
20
Q
Clinical significance of complete circumvallate placenta
A
Increased frequency of:
1. LBW
2. Antepartum bleeding
3. Premature labor
4. Fetal hypoxia
21
Q
Type of seizures in eclampsia
A
Tonic-clonic seizures
22
Q
Define HELLP syndrome
A
Epigastric pain in pre-eclamptic patients:
1. Hemolytic anemia
2. Elevated liver enzymes
3. Low platelet
23
Q
Pathologic placental findings in pre-eclampsia
A
- Small placenta
- Multiple infarcts
- Decidual vasculopathy (smooth muscle presists, thrombosis, acute atherosis)
- Villous hypermaturity
24
Q
Types of extrachorial placenta
A
- Circumvallate
- Circummarginate
25
Example of malformation syndrome
Down syndrome
26
Define agenesis
Absence of organ primordium
27
Define aplasia
Failure of organ primordium to develop beyond primitive form
28
Define atresia
Abnormal absence or closure of an organ orifice or passage
29
Limitations of abortus tissue for cytogenetic analysis?
1. Contamination with maternal cells
2. Fetal cells must be viable (grown in culture for metaphase)
30
Estimate fetal death before delivery?
0-1 day: red skin with slippage, peeling
2-7 days: red serous fluid, extensive peeling
>14 days: yellow-brown liver, mummification, FVM findings
31
Findings in Trisomy 13 (Patau syndrome)
CNS: absence of olfactory bulbs, microophthalmia
Face: Microcephaly, cleft lip and palate
Polydactyly
VSD, PDA, ASD
Single umbilical artery
32
Findings in Trisomy 18 (Edward)
Face: small mouth, micronagthia, low set ears
Hands/Feet: short dorsiflexed toe, index finger overlaps third finger
Valvular abnormalities
SGA, short sternum
33
Findings in Trisomy 21
CNS: open operculum in brain
Face: flat facies, oblique palpebral fissure, epicanthal folds
Hands/feet: Simian crease, sandal deformity
Heart: ASD, VSD
34
Findings in Monosomy X
Nuchal cystic hygroma
Marked edema of dorsal faces
Coarctation of the aorta
35
Genetic abnormalities in Turner syndrome
50% monosomy X
50% partial or complete deletion of small arm of X or mosaics
36
Manifestations of Turner in adolescent girls and young women
1. Short stature
2. Hypogonadism
3. Streak ovaries
4. Failure of development of secondary sex characteristics
5. Short webbed neck
6. Broad chest, widely spaced nipples
7. CHD
8. Melanocytic nevi
37
Genetic abnormalities in Down
95% Trisomy 21
3% translocations
2% mosaics
38
Risk factor for Down
Maternal age >45 years
39
Later manifestations of Down syndrome
1. Increased chances of acute leukemia (usually lymphoblastic)
2. Alzheimer changes in the brain
3. Diminished life expectancy
40
Main autopsy findings in congenital HSV
Microcephaly
Hydrocephaly
Microphthalmia
41
Main autopsy findings in congenital CMV
Microcephaly
Hydrocephaly
Microphthalmia
Giant cell hepatitis
Cholangitis
Viral inclusions in lung and kidneys
Arterial and periventricular calcification
42
Main autopsy findings in congenital toxoplasmosis
Usually asymptomatic
Severe: Hydrocephaly or microcephaly, intracranial calcifications, hepatosplenomegaly, jaundice, chorioretinitis, CSF pleocytosis
43
List 5 well documented teratogens
1. Thalidomide
2. Folate antagonists
3. Ethanol
4. Androgenic hormones
5. Warfarin
6. Retinoic acid
7. Valproic acid
44
Teratogen example and outcome
Valproic acid - homeobox protein transcription, important for limb, vertebrae, and craniofacial development
45
Fetal alcohol syndrome vs fetal alcohol spectrum disorders?
FASD - only subtle cognitive or behavioral defects
FAS - growth retardation, microcephaly, ASD, short palpebral fissures, maxillary hypoplasia
46
List the types of twin placentation
Dichorionic diamniotic twin placentas (2 discs).
Dichorionic diamniotic twin placenta (fused, 1 disc).
Monochorionic diamniotic twin placenta.
Monochorionic monoamniotic twin placenta.
47
Describe chronic histiocytic intervillositis (CHI)
Defined as an infiltrate of histiocytic-predominant mononuclear cells in the intervillous space
48
Clinical manifestations of preeclampsia
1. Pregnancy induced hypertension and proteinuria develop after 20 gestational weeks
2. Subcutaneous edema
3. Epigastric pain/liver tenderness
49
Placental gross and histologic findings of preeclampsia
1. Small
2. Multiple infarcts
3. Decidual vasculopathy: lack of physiologic conversion (smooth muscle persists), thrombosis, and acute
atherosis (fibrinoid necrosis plus macrophages)
4. Accelerated villous maturation
50
Excess exposure to retinoic acid?
Craniofacial defects (cleft lip and palate)
CNS defects
Heart defects
51
Deficiency of retinoic acid
Ocular, genitourinary, cardiovascular, pulmonary, and diaphragmatic malformations
52
Risk period for rubella
Until 16 weeks AOG
(especially first 8 weeks)
53
Tetrad of congenital rubella
1. Cataracts
2. Congenital heart defects (persistent ductus arteriosus, pulmonary artery stenosis, ventricular septal defect,
and tetralogy of Fallot)
3. Deafness
4. Mental retardation
54
Neonatal HSV findings at autopsy?
1. Hepatoadrenal necrosis
2. Vesicular skin rash
3. Vesicular/ulcerated stomatitis, esophagitis
4. Necrotizing pneumonitis
5. Chorioretinitis
55
Infection of parvovirus B19 in childhood
erythema infectiosum
56
Infection of parvovirus B19 in pregnancy
Usually normal
Can have congenital anemia, hydrops fetalis, and spontaneous abortion
Characteristic intranuclear viral inclusions can often be identified in
fetal nucleated red blood cells.
57
Types of hydrops fetalis
Severe: hydrops fetalis, generalized edema
Less severe: pleural effusion, peritoneal effusion, cystic hygroma
58
Major causes of nonimmune hydrops
1. Infections other than parvovirus — CMV, syphilis, toxoplasmosis
2. Malformations — especially thoracic (e.g., congenital pulmonary airway malformation, diaphragmatic hernia)
or urinary tract.
3. Twin-twin transfusion.
4. Metabolic disorders
59
Define immune hydrops
Hemolytic disorder caused by blood group antigen incompatibility between mother and fetus
60
Why is Rh disease uncommon in the first pregnancy
Maternal exposure to fetal RBCs occurs in the last trimester when placental villi cytotrophoblasts are absent, or
during delivery. Exposure initially invokes an IgM antibody response and IgM, unlike IgG, does not cross the
placental barrier
61
Describe prophylaxis for immune hydrops
Rh negative mothers receive Rhesus immune globulin containing anti-D antibodies at 28 weeks gestation and
within 72 hours of delivery, as well as after abortions
62
Why does maternal-fetal ABO incompatibility not cause problems?
1. Most anti-A and anti-B antibodies are IgM and don’t cross the placenta.
2. Neonatal RBCs express A and B blood group antigens poorly.
3. Fetal cells other than RBCs express them and can absorb transferred antibodies.
63
Under what circumstances is ABO hemolytic disease of the newborn most likely to occur
Almost exclusively in blood group A or B infants born to group O mothers who possess preformed IgG
antibodies directed at group A and/or B antigens
Can happen in first pregnancies
64
2 common signs and symptoms of excessive destruction of red blood cells in neonates
1. Anemia
2. Jaundice
65
Define SIDS
Death of an infant < 1 year that cannot be explained by clinical
history, examination of the death scene, or autopsy
66
What is the distinction between SIDS and SUID?
SUID stands for sudden unexpected infant death — a subset of these are true SIDS cases
67
3 risk factors in triple-risk model of SIDS
(1) a vulnerable infant
(2) a critical developmental period in homeostatic control
(3) an
exogenous stressor
68
Risk factors
1. Young maternal age (< 20 years).
2. Maternal smoking during pregnancy.
3. Drug abuse in either parent.
4. Short intergestational intervals.
5. Late or no prenatal care.
6. Poverty.
7. Brainstem abnormalities with associated defective arousal and cardiorespiratory control.
8. Prematurity and/or low birth weight.
9. Male sex.
10. Product of a multiple birth.
11. SIDS in a prior sibling.
12. Germline polymorphisms in autonomic nervous system genes.
13. Antecedent respiratory infections.
14. Prone or side sleeping position.
15. Sleeping on a soft surface.
16. Co-sleeping in first 3 months of life.
17. Hyperthermia.
69
List causes of respiratory distress syndrome
1. Neonatal respiratory distress syndrome (hyaline membrane disease).
2. Excessive sedation of the mother.
3. Fetal head injury, or aspiration of blood or amniotic fluid, at delivery.
4. Cord accident causing intrauterine hypoxic insult
70
Gross features of RDS in newborns
1. Normal size, solid and not aerated
2. Poorly-aerated, do not float in water
3. Reddish purple color like normal liver
71
List at least 3 risk factors for neonatal hyaline membrane disease
1. Preterm delivery (but weight appropriate for gestational age).
2. Caesarean delivery.
3. Male infant.
4. Diabetic mother
72
Microscopic features of RDS
1. Poorly developed alveoli
2. Collapsed alveoli
3. Pink hyaline membranes
73
Infants who recover from RDS are at increased risk for what conditions
1. Patent ductus arteriosus.
2. Intraventricular hemorrhage.
3. Necrotizing enterocolitis.
4. Retinopathy of prematurity (retrolental fibroplasia).
5. Bronchopulmonary dysplasia
74
What lecithin/sphingomyelin ratio is protective
>2:1
75
List 2 serious complications of oxygen therapy
Retrolental fibroplasia (retinopathy of prematurity).
Bronchopulmonary dysplasia
76
Complication of NEC after survival
Fibrotic structures
77
Clinical signs of NEC
1. Bloody stools
2. Abdominal distention
3. Circulatory collapse
4. X-ray: Gas in intestinal wall (pneumatosis intestinalis)
78
Gross findings in NEC
Distended, friable, congested bowel
Usually in TI, cecum, ascending colon
79
Etiology of NEC
1. Alteration of the microbiome associated with enteral feeding seems likely.
2. Infectious agents (none uniformly cultured) may also contribute.
3. Increased mucosal permeability due to elevated inflammatory mediators such as platelet activating factor
(PAF) permits migration of gut bacteria
80
Genetics of Gaucher
1. Autosomal recessive
2. Mutations in gene encoding glucocerebrosidase
3. Results in glucocerebrosides (from dying RBCs, WBCs) accumulate in cels
81
Types of Gaucher disease
1. Type 1 = chronic nonneuronopathic, with reduced but detectable enzyme levels, Ashkenazi, splenomegaly
2. Type 2 - acute neuronopathic with hepatosplenomegaly and progressive CNS involvement
3. Type 3 - systemic involvement, like Type 1, subacute neuronopathic
82
Genetics of phenylketonuria
1. Autosomal recessive
2. PAH gene mutation
3. Cannot convert phenylalanine to tyrosine, have hyperphenylalaninemia
83
Consequences of PKU
Normal at birth but severe mental retardation at 6 months
Brain - decreased weight, defective myelination, gliosis
84
Clinical presentation of PKU
1. Seizures and other neurologic abnormalities.
2. Decreased pigmentation of hair and skin (due to a deficiency of tyrosine, a precursor of melanin).
3. A musty odor.
4. Eczema.
85
How is PKU diagnosed in a newborn
Neonatal screening of a blood spot
86
Other problem with PKU (not PAH)
Enzyme cofactor tetrahydrobiopterin (BH4)
2% of cases
Cannot be treated by dietary restrition
87
Uncontrolled maternal PKU in pregnancy?
Metabolites can cross placenta and cause:
1. Microcephaly
2. Mental retardation
3. CHD
88
Genetics of galactosemia
1. Autosomal recessive
2. From accumulation of galactose-1-phosphate because not converted to glucose
3. Either deficiency of galactokinase or galactose-1-phosphate uridyl transferase (GALT, severe)
89
Consequences of GALT deficiency
1. G1P in liver, eyes, brain
2. Failure to thrive from birth
3. Vomiting and diarrhea on milk
4. Jaundice, hepatomegaly
5. Cataracts
6. Mental retardation
7. Aminoaciduria due to impaired kidney function
8. Hemolysis and coagulopathy
9. E. coli septicemia due to impaired neutrophilic bactericidal activity
10. If older - speech disorder, gonadal failure, ataxia
90
Describe the locations of first, second, and third branchial cleft cysts
1: Adjacent to EAC, pinna, or parotid
2. From persistence of cervical sinus
3. Rare, lateral neck
91
Embryogenesis of thyroglossal duct
Vestigial remnant of the tubular development of the thyroid gland
92
Histologic findings
1. +/- thyroid follicles
2. midline neck, anterior to trachea
3. may have squamous or respiratory columnar epithelium
93
Pulmonary histology of CF
1. Bronchioles distended with thick mucous.
2. Marked hyperplasia and hypertrophy of mucous secreting cells lining the respiratory tract.
3. Chronic bronchitis, bronchiectasis, and abscesses.
94
3 most common infectious organisms for CF patients and a fourth group of highly problematic
organisms
1. S. aureus
2. H. influenzae
3. P. aeruginosa
4. Burkholderia cepacia - cepacia syndrome, necrotizing pneumonia
95
Most common causes of CF death in North America
1. Chronic lung infections, obstructive pulmonary disease, and cor pulmonale (80% of deaths).
2. Complications post lung transplantation.
3. Liver disease (adults).
96
Classification of CF mutations
Class I — defective protein synthesis (null mutations).
Class II — abnormal protein folding, processing, and trafficking (processing mutations).
Class III — defective regulation (gathering mutations).
Class IV — decreased conductance (conduction mutations).
Class V — reduced abundance (production mutations).
Class VI — decreased membrane CFTR stability (instability mutations)
97
Prognosis of CF mutations (based on classifications)
1-3: severe, pancreatic insufficiency, sinopulmonary infections, GI symptoms
4-6: mild
98
Explain the role of genetic and environmental modifiers in the pulmonary manifestations of CF
Genetics - can affect neutrophil function
Environmental - bacteria producing alginate use gel for protection against cellular or humoral immune response
99
Gene and chromosome number in CF
cystic fibrosis transmembrane conductance regulator (CFTR) gene
Chromosome 7
100
Function of CFTR protein
Forms a chloride channel
Also regulates other channels
101
Relevance of bicarbonate ion transport in CF
If affected: in pancreas, epithelial secretions are too acidic, pancreatic ducts are plugged with mucin, and exocrine pancreas become atrophic
102
Pathogenesis of Hirschsprung
Submucosal (Meissner) plexus and myenteric (Auerbach) plexus ganglion cells develop from neural crest cells
that migrate to and populate the bowel wall during development
Proximal dilated colon
103
Genetic abnormality in Hirschsprung?
1. Sporadic
2. LOF mutation in RET
104
Incidence of Hirschsprung
1 in 5000 births, increased in Down's
105
2 major histologic features in colonic resections with Hirschsprung disease
1. Ganglion cells are absent in submucosal (Meissner) plexus and myenteric (Auerbach) plexus.
2. Hypertrophic nerve fibers in submucosa are usually present
106
Name an immunohistochemical stain that can help diagnose Hirschsprung disease
Calretinin
- reactive small fibers in LP and MM in normal bowel
107
Define heterotopia or choristoma
Microscopically normal cells or tissues present in abnormal locations
108
Examples of heterotopia
1. Pancreatic tissue in the wall of the small intestine.
2. Pancreatic or gastric tissue in a Meckel diverticulum.
3. Adrenal cortical rests in a variety of sites, such as adjacent to a gonad.
4. Thymic rest adjacent to the thyroid.
109
Clinical significance of heterotopia
Can give rise to a primary
neoplasm in an unexpected site
110
Define hamartoma
Focal overgrowth of normal, mature cells or tissues native to an organ, but not reproducing the
normal architecture of the surrounding normal tissue
111
List 3 types of benign tumors in infancy and childhood
1. Hemangioma
2. Lymphangioma
3. Fibromatosis/congenital-infantile fibrosarcoma
112
Strange features of hemangioma in infancy vs childhood
1. Capillary hemangiomas can be more cellular
2. Hemangiomas can be due to an underlying hereditary disorder
3. Infantile hemangioma can regress spontaneously
113
Prognosis of fibromatosis/congenital-infantile fibrosarcoma
Good prognosis
114
Chromosomal translocation in fibromatosis/congenital-infantile fibrosarcoma
t(12;15)
ETV6-NTRK3
Constitutively active through PI3/AKT pathway
115
Teratomas can be mixed with what other GCT
YST
Embryonal carcinoma
116
Sacrococcygeal teratomas are often associated with what?
Congenital anomalies (sacral body defect, in hindgut or cloacal region)
117
Most common type of leukemia in kids
Acute lymphoblastic leukemia
118
Differentials of small round blue cell tumors in head
medulloblastoma
atypical teratoid/rhabdoid tumors (AT/RT)
neuroblastoma
retinoblastoma
olfactory
neuroblastoma (esthesioneuroblastoma)
rhabdomyosarcoma
119
Differentials of small round blue cell tumors in thorax
Askin tumor (malignant small cell tumor of thoracopulmonary origin, Ewing family of tumors)
rhabdomyosarcoma lymphoma
pleuropulmonary blastoma
120
Differentials of small round blue cell tumors in abdomen
neuroblastoma
rhabdomyosarcoma
lymphoma
Wilms tumor
Ewing sarcoma
desmoplastic small
round cell tumor
121
Molecular prognosticators for neuroblastoma
MYCN amplification
1p deletion
11q deletion and/or 17q gain
DNA index
122
Molecular prognosticators for Burkitt
c-MYC gene (chromosome 8)
translocations
t(2;8), t(8;14), or t(8;22)
123
Molecular prognosticators for alveolar rhabdomyosarcoma
PAX3/FOXO1 fusion gene, t(2;13)
PAX7/FOXO1 fusion gene, t(1;13) - better prognosis
124
Molecular prognosticators for Ewing sarcoma
EWSR! gene on chr 22 and FLI1 (chr 11)
ERG - chr 21
125
Fusion for desmoplastic small round blue cell tumor
EWS/WT1 fusion
126
List 3 histologic features of neuroblastoma
1. Nesting pattern: usually ill-defined organoid nests with thin fibrovascular septa.
2. Neuroblasts — various differentiation:
Nucleus: from small blue round to progressively enlarged, vesicular.
Cytoplasm: from scanty to abundant.
Neurofibrillary processes (neuropil).
Differentiation toward ganglion cells.
Homer-Wright pseudorosettes.
3. Schwannian stroma: < 50% of the tumor
127
The INPC distinguishes between 2 prognostic groups of untreated neuroblastoma?
Favorable histology (FH)
Unfavorable histology (UH)
128
Basis of INPC classification
Schwannian stroma
Ganglionic differentiation
Mitotic and
karyorrhectic index (MKI)
Patient age
129
INPC classifications
Neuroblastoma Schwannian stroma poor (undifferentiated, poorly-diff, differentiating)
Ganglioneuroblastoma, nodular (composite, Schwannian stroma-rich/dominant, stroma-poor)
Ganglioneuroblastoma, intermixed (Schwannian stroma-rich)
Ganglioneuroma (Schwannian stroma dominant)
130
Tumor stage (International Neuroblastoma Risk Group Staging System [INRGSS]) parameters for neuroblastoma
Pretreatment imaging
Patient age
Clinical extent of disease
131
Tumor stage INRGSS
Stage L1— localized tumor not involving vital structures as defined by the list of image-defined risk factors
and confined to 1 body compartment.
Stage L2 — locoregional tumor with presence of ≥ 1 image-defined risk factors.
Stage M — distant metastatic disease (except stage MS).
Stage MS — metastatic disease in children < 18 months with metastases confined to skin, liver, and/or bone
marrow with minimal marrow involvement
132
Prognostic parameters of low-risk or intermediate-risk neuroblastoma
<18 months of age
Hyperdiploid chromosomes
133
Prognostic parameters of high-risk neuroblastoma
>18 months of age
Segmental chromosome abnormalities (gains/losses)
MYCN gene amplification
134
Key genomic characteristics of neuroblastic tumors
1. MYCN
2. ALK - familial predisposition
3. ATRX - older children
4. DNA index - near diploid/tetraploid is unfavorable
5. Hemizygous deletion of distal short arm of chromosome 1
6. Segmental chromosome aberrations - 1p deletion, 11q del, 17q gain
7. Alterations in numbers of whole chromosomes (lower risk tumors)
135
Positive IHC in rhabdomyosarcoma
Desmin, MSA, myoD1, myogenin
136
Positive IHC in neuroblastoma
PGP9.5, NB84, synaptophysin, NSE
137
List 2 biochemical markers for neuroblastoma
1. vanillylmandelic acid (VMA)
2. homovanillic acid (HVA)
Urine/blood
Catecholamines may not be increased in undifferentiated neuroblastomas
138
3 key syndromes associated with Wilms tumor
1. WAGR
2. Denys-Drash
3. Beckwith-Wiedemann syndrome (BWS)
139
Characteristics of WAGR syndrome
Wilms, aniridia, genitourinary anomalies, mental retardation (intellectual disability)
140
Mutations in WAGR
Germline deletion of WT1 and PAX6 (aniridia)
141
Characteristics of Denys-Drash syndrome
Wilms tumor
Gonadal dysgenesis
Early-onset nephropathy (diffuse mesangial sclerosis)
142
Syndrome with Wilms and high risk for gonadoblastoma
Denys-Drash syndrome
143
Mutation in Denys-Drash
Germline dominant–negative missense mutation in the zinc-finger region of WT1
- interferes with the function of the other normal allele
144
Characteristics of Beckwith-Wiedemann syndrome (BWS)
Macrosomia
Organomegaly
Macroglossia
Hemihypertrophy
Omphalocele
Adrenal cytomegaly
145
Affected genes in Beckwith-Wiedemann syndrome
WT2 locus, IGF-2 in this region
146
Imprinting in BWS
1. Re-expression of maternal allele of IGF-2 (loss of imprinting)
2. Duplication of transcriptionally active paternal allele (uniparental paternal disomy)
147
Presence of anaplasia in Wilms correlates with?
p53 mutations
chemotherapy resistance
148
Histologic features in Wilms
Blastemal (sheets of small blue cells)
Stromal (fibroblastic, myxoid, occasionally skeletal muscle)
Epithelial (abortive tubules and glomeruli)
149
Precursor of Wilms
Nephrogenic rests
150
Significance of nephrogenic rests
Increased risk of developing Wilms in contralateral kidney
151
Site of Ewing sarcoma in bone
Medullary cavities
152
Sites of predilection
Long bones
Pelvis
153
Radiologic findings of Ewing
1. Destructive lytic tumor extending to soft tissue
2. Elevation of periosteum
3. Onionskin layering
154
Histologic findings of Ewing sarcoma
Sheets of uniform small round blue cells.
Homer-Wright rosettes.
Sparse intercellular stroma.
Few or no mitoses.
Intracytoplasmic glycogen (clear cytoplasm).
CD99+
155
List tumors with involvement of EWSR1 gene
Ewing sarcoma family of tumors.
Desmoplastic small round cell tumor.
Angiomatoid fibrous histiocytoma.
Clear cell sarcoma of soft parts.
Extraskeletal myxoid chondrosarcoma.
Extraskeletal chondrosarcoma.
Myoepithelioma
156
Clinical presentation of ABC
1. First 2 decades of life
2. Rapid onset of pain and swelling
157
Where does ABC most commonly arise?
Long bones (metaphysis)
158
Radiologic findings in ABC
X-ray: sharply defined, expansile osteolytic lesion with thin sclerotic borders.
CT: fluid-fluid levels.
159
Differential diagnosis of ABC
1. Telangiectatic osteosarcoma.
2. Giant cell tumor.
3. Non-ossifying fibroma
4. Fracture
160
Genetic basis of ABC
Rearrangements of chromosome 17p13 lead to USP6 overexpression
161
What type of virus is ABC
Herpes-type virus
162
Pathogenesis of EBV
Infects B lymphocytes and epithelial cells
viral glycoprotein gp350 and CD21 on lymphocytes
163
EBV gene products in EBV infected cells
EBV nuclear antigens (EBNA-1, EBNA-2, EBNA-3).
Latent membrane proteins (LMP1, LMP2) localized in the plasma membrane of infected B cells.
Nonpolyadenylated nuclear RNAs, EBER1 and EBER2 (which are often used to detect the presence of EBV
within a cell)
164
5 diseases associated with EBV infection
Infectious mononucleosis (100%).
Burkitt lymphoma (endemic > 90%, nonendemic 15%–20%).
Nasopharyngeal carcinoma (100%).
Chronic active EBV infection (100%).
Hodgkin lymphoma (mixed cellularity 70%, lymphocyte-rich 40%, nodular sclerosis usually EBV negative).
Primary CNS lymphoma (> 90%).
Posttransplant lymphoproliferative disorder.
Oral hairy leukoplakia (100%).
EBV-associated smooth muscle tumor (100%).
Extranodal NK/T cell lymphoma, nasal type.
Angioimmunoblastic T cell lymphoma.
EBV-associated gastric carcinoma.
