1
PEDIATRIC SCIENCE MSK/RHEUM -
PATHOPHYSIOLOGY
Pectus excavatum results from failed growth
and fusion of the costal cartilages, leading to
What is the posterior displacement of the sternum.
pathophysiology of
This causes a decreased anteroposterior
Pectus Excavatum?
thoracic
diameter. In severe cases, this reduces lung capacity
and
compresses the right heart (atrium and
ventricle), lowering stroke volume, especially
during exertion.
A 14-year-old Pectus Excavatum
athletic boy
presents with
fatigue during
exercise and
shortness of
breath. On exam, he has
a visible sunken
sternum with a
noticeable chest
depression.
Pectus carinatum occurs due to overgrowth of
costal cartilages, which pushes the sternum
What is the
pathophysiology of anteriorly. The deformity is often
,2
Pectus Carinatum? symmetrical and may result from abnormal
ossification of the costal cartilage. Unlike
excavatum, it does not usually impair
cardiopulmonary function.
A 13-year-old girl Pectus Carinatum
presents with concerns
about her chest
protruding outward.
On exam, the
sternum is
symmetrically
protruding like a
keel, with no
respiratory
compromise.
Poland syndrome results from disruption
of blood flow in the subclavian artery or its
What is the branches during embryogenesis (around
pathophysiology of
week 6). This vascular disruption leads to
Poland Syndrome?
hypoplasia or absence of the pectoralis
major muscle and sometimes adjacent
chest wall structures. It may also involve
ipsilateral upper limb anomalies like
syndactyly.
,3
A 7-year-old boy Poland Syndrome
presents with
asymmetry of the
chest and absence of
the right nipple.
Exam shows
underdevelopment of
the right pectoralis
major and fused
fingers on the same
side.
Cleft sternum occurs due to failure of
What is the midline fusion of the paired sternal bars
pathophysiology of
during the eighth week of embryogenesis.
Cleft Sternum?
The result is a partial or complete defect in
the sternum, which can expose the heart
beneath the skin in severe cases.
A newborn presents Cleft Sternum
with a visible midline
chest gap where the
sternum should be.
A soft, pulsating
bulge is seen under
the skin.
Thoracic ectopia cordis results from severe failure of
What is the ventral
pathophysiology of body wall closure during embryogenesis. The
Thoracic Ectopia Cordis? defect involves the sternum, diaphragm, and
pericardium, causing the heart to develop
partially or fully outside the thoracic cavity.
, 4
A neonate is delivered Thoracic Ectopia Cordis
via
emergency C-section
and has a visible heart
beating outside of the
chest. Immediate
surgery is required.
Cantrell’s Pentalogy arises from defective
What is the migration of lateral mesoderm during
pathophysiology of embryogenesis, resulting in five midline
Thoracoabdominal defects: a lower sternum defect, anterior
Ectopia Cordis (Cantrell’s diaphragmatic defect, absence of the
Pentalogy)? diaphragmatic pericardium, omphalocele
(abdominal wall defect), and intracardiac
anomalies like VSD.
A newborn Thoracoabdominal Ectopia Cordis (Cantrell’s Pentalogy)
presents with an
omphalocele,
visible heart
beneath a thin
membrane, and an
absent sternum.
Echocardiogram shows a
ventricular septal defect.
Jeune syndrome is caused by mutations in
ciliary genes (such as IFT80 or DYNC2H1),
What is the
pathophysiology of leading to defective endochondral
Jeune Syndrome? ossification. This results in a narrow, bell-
shaped thoracic cage, shortened ribs, and
restrictive pulmonary disease due to
reduced lung volume.
PEDIATRIC SCIENCE MSK/RHEUM -
PATHOPHYSIOLOGY
Pectus excavatum results from failed growth
and fusion of the costal cartilages, leading to
What is the posterior displacement of the sternum.
pathophysiology of
This causes a decreased anteroposterior
Pectus Excavatum?
thoracic
diameter. In severe cases, this reduces lung capacity
and
compresses the right heart (atrium and
ventricle), lowering stroke volume, especially
during exertion.
A 14-year-old Pectus Excavatum
athletic boy
presents with
fatigue during
exercise and
shortness of
breath. On exam, he has
a visible sunken
sternum with a
noticeable chest
depression.
Pectus carinatum occurs due to overgrowth of
costal cartilages, which pushes the sternum
What is the
pathophysiology of anteriorly. The deformity is often
,2
Pectus Carinatum? symmetrical and may result from abnormal
ossification of the costal cartilage. Unlike
excavatum, it does not usually impair
cardiopulmonary function.
A 13-year-old girl Pectus Carinatum
presents with concerns
about her chest
protruding outward.
On exam, the
sternum is
symmetrically
protruding like a
keel, with no
respiratory
compromise.
Poland syndrome results from disruption
of blood flow in the subclavian artery or its
What is the branches during embryogenesis (around
pathophysiology of
week 6). This vascular disruption leads to
Poland Syndrome?
hypoplasia or absence of the pectoralis
major muscle and sometimes adjacent
chest wall structures. It may also involve
ipsilateral upper limb anomalies like
syndactyly.
,3
A 7-year-old boy Poland Syndrome
presents with
asymmetry of the
chest and absence of
the right nipple.
Exam shows
underdevelopment of
the right pectoralis
major and fused
fingers on the same
side.
Cleft sternum occurs due to failure of
What is the midline fusion of the paired sternal bars
pathophysiology of
during the eighth week of embryogenesis.
Cleft Sternum?
The result is a partial or complete defect in
the sternum, which can expose the heart
beneath the skin in severe cases.
A newborn presents Cleft Sternum
with a visible midline
chest gap where the
sternum should be.
A soft, pulsating
bulge is seen under
the skin.
Thoracic ectopia cordis results from severe failure of
What is the ventral
pathophysiology of body wall closure during embryogenesis. The
Thoracic Ectopia Cordis? defect involves the sternum, diaphragm, and
pericardium, causing the heart to develop
partially or fully outside the thoracic cavity.
, 4
A neonate is delivered Thoracic Ectopia Cordis
via
emergency C-section
and has a visible heart
beating outside of the
chest. Immediate
surgery is required.
Cantrell’s Pentalogy arises from defective
What is the migration of lateral mesoderm during
pathophysiology of embryogenesis, resulting in five midline
Thoracoabdominal defects: a lower sternum defect, anterior
Ectopia Cordis (Cantrell’s diaphragmatic defect, absence of the
Pentalogy)? diaphragmatic pericardium, omphalocele
(abdominal wall defect), and intracardiac
anomalies like VSD.
A newborn Thoracoabdominal Ectopia Cordis (Cantrell’s Pentalogy)
presents with an
omphalocele,
visible heart
beneath a thin
membrane, and an
absent sternum.
Echocardiogram shows a
ventricular septal defect.
Jeune syndrome is caused by mutations in
ciliary genes (such as IFT80 or DYNC2H1),
What is the
pathophysiology of leading to defective endochondral
Jeune Syndrome? ossification. This results in a narrow, bell-
shaped thoracic cage, shortened ribs, and
restrictive pulmonary disease due to
reduced lung volume.
