F. Gülen et al. / Open Journal of Pediatrics 1 (2011) 75-78 77
aldi classification and is of third degree according to
Boyden.
There are primary (idiopathic) and secondary causes
in the etiology of the pulmonary hypoplasia. It usually
occurs secondary to the intrauterine diseases impairing
normal lung development. Deformities of the chest wall,
pleural effusion associated with hydrops fetalis, cystic
adenomatoid malformation, and diaphragmatic hernia
physically limits the development of the lung. Further-
more, conditions leading to oligohydramnios such as
early rupture of the membranes or fetal renal insuffi-
ciency also impair development of the lungs [1]. Hy-
poplasia may be bilateral in thoracic dystrophies and
oligohydramnios. In such cases, development of the air-
ways and arterial truncation is inhibited and th u s, surface
area required for alveolo-capillary gas exchange be-
comes limited [1,7].
Isolated pulmonary hypoplasia is rare; it is generally
accompanied by anomalies in other systems, especially
in the cardiovascular, gastrointestinal, musculoskeletal
and urogenital systems. Severity of the clinical symp-
toms and timing of their occurrence is related to the de-
gree of hypoplasia [14]. It usually presents with respira-
tory distress or pulmonary hypertension in the newborn
period. Respiratory distress in the first five minutes fol-
lowing birth is typical for these patients, and they usu-
ally require mechanical ventilation. Apgar scores are
usually found to be lower, although babies with com-
pletely normal Apgar scores may also be seen [11,
15-19]. However, as in our patient, patients who remain
asymptomatic until pub erty have also be en reported [7,9 ,
10]. Total atelectasia, pleural effusion, pneumonia, dia-
phragmatic elevation, diaphragmatic hernia, pulmonary
aplasia, and pneumonectomy should be considered in
differential diagnosis of these patients. Postero-anterior
chest radiograph, thoracic CT, CT angiography, MR an-
giography and bronchoscopy may be used for diagnosis
[14]. Some pathologists suggested that radial alveolar
counting (RAC) might be used for confirming the diag-
nosis of hypoplasia [20]. In this method, number of the
alveoli taken from a region between the respiratory
bronchiole and the closest connective tissue is compared
to a normal control sample in the same laboratory. This
rate was found to be reduced in two published studies
[11,15,21-24], although another study did not support
this assumption [18].
Life-span of the patients depends on severity of
anomalies of other systems and degree of the pulmonary
hypoplasia [1]. Mortality has been reported to be high
(71% - 95%) especially in those cases manifesting in the
newborn period [11,25]. Membrane rupture earlier than
25th week of the gestation, presence of severe oligohy-
dramnios (amniotic fluid index < 4) for more than 2
weeks, and preterm labor have been reported to be con-
ditions increasing mortality [25]. Some prenatal inter-
ventions may be attempted to increase fetal lung capac-
ity or to provide lung development, depending on the
underlying etiologic reason. Tocolitics for early mem-
brane rupture, antibiotics, steroids, use of fibrin glue to
correct the lesion transcervically, and consecutive use of
amnio-infusions are methods used currently in several
centers and of which benefits have been reported in
some references [25]. Additionally, other methods in the
postnatal period include mechanical ventilation, provid-
ing ECMO (extracorporeal membrane oxygenation) and
surfactant support, and early initiation of dialysis to
support renal function. No method with proven efficacy
has been found although some surgical techniques are
being tried [25].
Unilateral hypoplasia is a congenital ano maly causing
a wide spectrum of clinical manifestations from mild,
non-specific findings to severe respiratory symptoms.
Our case was presented with nonspecific findings, who
remained asymptomatic until puberty, which is a rare
clinical presentation of pulmonary hypoplasia. In pa-
tients with unilateral hypolucen t lung, although it is seen
rarely, pulmonary hypoplasia should always be kept in
mind.
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