*2.3.1. Environmental causes*

No cases of CDH in humans have been unequivocally attributed to teratogenic or environmental exposures. Recently, a potential association with the immunosuppressive drug mycophenylate mofetil has been made, but the mechanism by which this drug could cause diaphragmatic defect is unknown [3].

**4.** Central hernia is rare; the diaphragm defect involves the central tendinous (amuscular) part of the diaphragm. In these cases, the entire rim of diaphragmatic musculature is found

**Found in this disorder Attributed to this disorder**

Very rare

Unknown

abnormality in prenatally diagnosed CDH

Congenital Diaphragmatic Hernia

189

http://dx.doi.org/10.5772/intechopen.74500

~30% ? < 5%

Trisomy 18 ?1–2% Rare among all CDH; most common chromosome

Rare Very rare

**6.** Diaphragmatic eventration is defined as an elevation or abnormal upward displacement of a part or entire normal diaphragm into the chest cavity. This rare type of CDH is caused by the existence of a thinner part of diaphragm which allows the upward displacement of

For practical reasons regarding the imaging approach and counseling, it was proposed to

Intrapleural hernias occur through defects in the muscular diaphragm, which may result from deficient fusion of the pleuroperitoneal membranes and abdominal wall musculature or absence of the pleuroperitoneal membranes. Intrapleural hernia contents cause compressions on intrathoracic visceras, causing pulmonary hypoplasia and contralateral mediastinal shift.

Mediastinal hernias can be classified into two types: retrosternal and central. Retrosternal hernias are categorized as Morgagni hernias, although a true Morgagni hernia is only a small anatomic located in the space between the sternal and costal heads of the diaphragm. True Morgagni hernia is considered to be a subtype of retrosternal mediastinal hernias, with larger

This category includes the traditionally classified Bochdalek hernias.

**Chromosome abnormality/locus Frequency of congenital diaphragmatic hernia**

Bochdalek hernias)

Trisomy 13 Rare Very rare

+der (22) t(11;22)(q23;q11) 5–10% Very rare

Del(1)(q41-q42) Unknown Unknown Del(8)(p23.1) ?30% Unknown

majority)

Trisomy 21 Rare (Morgagni hernias >

Del(15)(q26.2) Unknown (?but possibly

**Table 1.** Common chromosome anomalies associated with CDH.

**5.** Hiatal hernia, extremely rare, occurs through a congenitally large esophageal orifice.

to be present.

Pallister-Killian syndrome/ (isochromosome or tetrasomy 12p)

Del(4)(p16) (Wolf-Hirschhorn

syndrome)

abdominal organs.

classify CDH as intrapleural and mediastinal.
