Congenital Diaphragmatic Hernia with Liver Herniation into the Pericardial Sac in a 30-Week Gestation Infant

Introduction

Congenital diaphragmatic defects comprise a spectrum of birth defects occurring in approximately 1 in 3000 live births. ¹ The most common and usually most severe are the defects of the posterolateral diaphragm, which include hernias that disrupt the lumbocostal triangle (Bochdalek hernia). Posterolateral hernias are more common on the left side, and the size of the hernia correlates with the degree of associated pulmonary hypoplasia. Less common and usually less severe hernias occur in the anterior diaphragm. These are usually not associated with pulmonary hypoplasia and occur in proximity to the sternum. Terminology varies for describing defects of the anterior diaphragm, but most often they are referred to as Morgagni Type hernias. While most anterior diaphragmatic defects are covered with a membrane or sac (non-communicating/eventration hernias), very rare types may allow direct communication of the liver with the thoracic cavity. Most congenital diaphragmatic defects are “isolated” and not associated with structural birth defects other than pulmonary hypoplasia. Rarely, a patient with congenital diaphragmatic defect also has multiple defects that comprise a recognized syndrome. Congenital heart disease (CHD), for example, is present in 10%–15% of non-syndromic CDH while CHD is present in 25%–40% of CDH cases with underlying syndromes or chromosomal anomalies. ² These syndromes include Fryns syndrome, Donnai–Barrow Syndrome, and Pentalogy of Cantrell.^1,3,4 The following case is of an unusual presentation of a rare type of anterior midline diaphragmatic defect that can be challenging to diagnose prenatally and can masquerade as a tumor.

Case Report

A 1360-g (45th percentile) baby girl was born at 30 2/7 weeks gestation via emergent caesarian section for concern of abruption. The pregnancy was complicated by preterm premature rupture of membranes (PPROM) at 23 weeks with oligohydramnios and intrauterine growth restriction. In addition, the baby was prenatally diagnosed with an atrioventricular septal defect (AVSD) with common atrioventricular valve and ventricular shunting, pericardial mass, and small pericardial effusion at 26 weeks gestation via ultrasound. The Apgar scores were 2, 5, and 8 at 1, 3, and 5 min, respectively, and she required immediate bag mask ventilation and chest compressions due to a drop in heart rate in the delivery room. She was intubated, received surfactant, and was transferred to our institution for evaluation of the pericardial mass.

Echocardiogram (Figure 1(a)) demonstrated a balanced AVSD (moderate atrial component with a small ventricular component), normal left and right ventricular systolic function, moderate atrioventricular valve regurgitation, and persistent patency of the arterial duct (patent ductus arteriosus) with bidirectional shunting. There was a large pericardial mass and a moderate pericardial effusion without definite features of tamponade. Due to rapidly evolving cardiopulmonary instability at 10 h of life, urgent needle pericardiocentesis was performed yielding 5 mL of straw-colored fluid. The patient’s blood pressure and perfusion temporarily improved; however, she still required significant cardiopulmonary support (high frequency ventilation, vasopressors, and fluid resuscitation). Repeat echocardiogram showed no residual pericardial effusion. The large pericardial mass (reported to be roughly half the size of the heart) persisted, abutting the right atrial and right ventricular free walls but not attached to either, and not obstructing ventricular inflow or outflow. The mass was fairly homogenous in appearance, with echotexture reminiscent of hepatic parenchyma, although continuity with the intra-abdominal liver could not be demonstrated echocardiographically or on subsequent abdominal ultrasound dedicated to this question. Chest and abdominal radiographs demonstrated hypoexpanded lungs with diffuse reticulogranular opacities, generously sized cardiothymic silhouette, and normal diaphragmatic contours (Figure 1(b)). The patient was too unstable to leave the NICU for CT or MRI imaging.

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Figure 1.

(a), Echocardiogram on day of life 1, prior to pericardiocentesis: The inferior pericardial border is not well demonstrated on this image but the anticipated position extrapolated from adjacent frames is indicated for clarity. The echo-dark area outside the pericardium is due to acoustic shadowing, not intra-abdominal fluid (E: effusion; LA: left atrium; LV: left ventricle; M: mass; P: pericardium; RA: right atrium; RV: right ventricle). (b), Chest radiograph on day of life 1, prior to pericardiocentesis: Lungs are somewhat hypoexpanded with diffuse reticulogranular opacities noted throughout. Cardiothymic silhouette is at the upper limit of normal. ET tube is above the thoracic inlet. Umbilical vascular catheter terminates at T7–T8.

The hospital course was complicated by persistent pulmonary hypertension, felt to be secondary to premature prolonged rupture of membranes and oligohydramnios. Ultimately, the patient’s cardiopulmonary status worsened despite maximal medical therapy and she died at 8 days of life.

Autopsy findings showed a midline anterior congenital diaphragmatic defect measuring 1.5 × 1.2 cm in greatest dimension with liver parenchyma extending 1.0 cm through the diaphragm and into the pericardial sac (Figures 2(a) and (b)). In addition, the previously known AVSD was identified with conjoined leaflets of the tricuspid and mitral valves across the ventricular septal defect. Other findings included left lower limb atrophy, bilateral posteriorly rotated ears and absence of inner helices, and a midline cleft in the gumline (Figure 2(c)). No features associated with oligohydramnios (equinovarus, broad hands, or low-set ears) were identified. Microscopically, there were bilateral lung cystic changes and intra-alveolar hemorrhage most consistent with iatrogenic ventilatory injury. The placenta was examined for pathology at the referring hospital and showed a 14-cm long trivascular umbilical cord, with acute umbilical phlebitis, and early acute chorioamnionitis.

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Figure 2.

(a), Anterior view of thorax and upper abdomen at the time of autopsy: a small nodule of liver (designated by *) is present above the diaphragm and in the pericardial sac (D: diaphragm; H: heart; L: liver; LL: left lung; P: pericardium; RL: right lung). (b), Superior view of the thorax at autopsy with the liver nodule (designated by *) protruding through the diaphragm into the pericardial sac (D: diaphragm; H: heart; L: liver; P: pericardium; RL: right lung). (c), Partial cleft in mid gumline. (d), Atrioventricular septal defect seen from the heart base looking down at the septal defect with the right and left ventricular free walls sectioned and splayed laterally (LV: left ventricular free wall; P: posterior heart; RV: right ventricular free wall; SD: septal defect; TV: tricuspid valve; arrow indicates tricuspid valve spanning through septal defect into left ventricle). (e), Atrioventricular septal defect seen from the left side of the heart (LVS: left ventricular septal wall; S: septum; SD: septal defect; TV: tricuspid valve; two-headed arrow indicates tricuspid valve spanning across septal defect into left ventricle).

Discussion

Congenital diaphragmatic hernias can exist either in isolation (50%–60% of cases), or in association with other anomalies within a syndrome. Anterior defects are uncommon (5% mainly of the Morgagni type),⁵ and intrapericardial diaphragmatic hernias are extremely rare. Very few reports of prenatally or perinatally diagnosed herniation of the liver into the pericardial sac have been reported in the literature (Table 1).^5–12

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Table 1.

Selected literature regarding CDHs involving liver herniations into the pericardium.

	Gestational age at time of fetal diagnosis (weeks)	Time of diagnosis	Size of herniation/intrapericardial mass	Clinical Course	Congenital heart disease	Pericardial effusion
Antinolo et al. 5	21	In utero	Liver filling right hemithorax	Surgery; survived	None	Yes
Aré et al. 6	33	In utero	3.5 × 3 cm intracardial mass	Survived	None	Yes
Robnett-Filly et al. 7	37	In utero	Approximately, half the volume of the liver was within the pericardium	Surgery; survived	VSD	Yes
Kanamori et al. 8	n/a	Postpartum four days	Segments 2, 3, and 4 (left lobe of liver)	Surgery; survived	None	Yes
Stevens et al. 9	37	In utero	6 × 6 cm defect in the pericardium	Surgery; survived	None	Yes
Einzig et al. 10	n/a	Postpartum three days	Not described	Surgery	None	Yes
Shely et al. 11	n/a	Postpartum 14 days	3 cm defect in right anterior diaphragmatic area	Surgeries × 2	ASD	No
deFonseca et al. 12 Case 1	n/a	At birth	Not described	Surgery; died due to nosocomial Klebsiella septicemia	None	Yes
deFonseca et al. 12 Case 2	n/a	At birth	Not described	Surgery	None	Yes
deFonseca et al. 12 Case 3	n/a	At autopsy	Not described	Died due to respiratory distress	None	Yes
Current case	26	In utero	1.5 × 1.2 cm	Died at eight days of life	AVSD	Yes

Although it is unusual for congenital diaphragmatic defects to involve the pericardium, a rare entity known as Pentalogy of Cantrell has been reported to include a midline diaphragm defect, cardiac anomalies (such as ventricular septal defect [VSD], atrial septal defect [ASD], or tetralogy of Fallot [TOF]), defects in the pericardium or sternum, omphalocele, and ectopia cordis. Our patient had three of the five features of this syndrome (an anterior midline diaphragmatic defect, pericardial defect, and AVSD) and therefore may represent a case of incomplete Pentalogy of Cantrell. Our patient also had a midline dental cleft, which has been previously reported in cases of Pentalogy of Cantrell. ¹³ Of note, ectopia cordis (exteriorization of the heart), which is defined as an abnormal position of the heart outside the thorax, ¹⁴ was not seen in our patient. However, the three other midline defects are still suggestive of a midline ventral developmental field defect that lies within the spectrum of Pentalogy of Cantrell that has been proposed by previous authors. ¹⁵ It has also specifically been suggested that defects in the transverse septum may cause the diaphragmatic defect associated with Pentalogy of Cantrell. ¹⁶ While all but one of the reported cases in Table 1 presented with pericardial effusion, few^7,11 had associated congenital heart disease. Our patient and 2 of 10 patients in the summarized literature with anterior diaphragmatic hernia and pericardial involvement did not survive. Our patient was too unstable for cross-sectional imaging, which would have likely revealed the herniation of the liver into the pericardium. The combination of prematurity and PPROM (with oligohydramnios and likely chorioamnionitis) put this infant at significant risk for persistent pulmonary hypertension (PPHN). Although the lung volume did not appear to be reduced on the right side secondary to the diaphragmatic defect, CDH has been associated with lung developmental defects, which may have contributed to the severity of the PPHN.^3,4 Although the patchy cystic change seen in the lungs bilaterally was attributed to iatrogenic causes (hyperventilation), these changes may have obscured an underlying congenital process, such as congenital pulmonary emphysema. The pattern of cystic change is not consistent with either congenital pulmonary airway malformation or congenital lymphangiectasia.

In summary, this patient had multiple prenatal ultrasounds showing a mass in the pericardial space and concurrent pericardial effusion. Although pericardial tumors such as fibromas, rhabdomyomas, and hemangiomas can also have this initial presentation, anterior diaphragmatic hernia with herniation of visceral organs into the pericardium should also be considered in the differential diagnosis. Since herniation of liver is more difficult to appreciate on prenatal ultrasound than that of stomach or intestine, most of these defects are not diagnosed until late gestation or after birth.^4,5 Early recognition of herniated liver as the etiology of a pericardial mass is essential for recognition of potential Pentalogy of Cantrell. A thorough screen for associated anomalies may provide insight into risk assessment and further management in these patients. When other anomalies are identified, such as congenital heart defects, sternal clefts, omphalocele, or ectopia cordis, the diagnosis of Pentalogy of Cantrell should be considered. In addition, the importance of discussing the value of autopsy with families is highlighted in this case. Without autopsy, this relatively small defect would likely not have been identified. Since CDH can have a genetic predisposition, genetic counseling might be indicated prior to future pregnancies in similar cases.