Radiological insights into a voluminous left-sided Morgagni-Larrey hernia: A case report

Abstract

Morgagni-Larrey hernia is a rare condition, accounting for less than 5% of congenital diaphragmatic hernias, with a marked predominance on the right side. Left-sided localizations are encountered rarely due to the protection afforded by the heart and pericardium. We report the case of a 17-year-old patient admitted to the emergency department with acute abdominal pain and dyspnea. Chest X-ray revealed a left basithoracic opacity with air-fluid level, confirmed by thoracoabdominal-pelvic computed tomography as corresponding to a left sided Morgagni-Larrey hernia. The hernial contents were particularly extensive, including the stomach, spleen, transverse colon, omentum, and tail of the pancreas. The patient underwent surgical reduction of the viscera and closure of the diaphragmatic defect, with a favorable postoperative outcome. This case illustrates the rarity of large left-sided Morgagni-Larrey hernias and highlights the importance of imaging, particularly CT, for diagnosis and surgical planning.

Introduction

Morgagni-Larrey hernia was first described by Giovanni Battista Morgagni in 1769 [1]. It results from a congenital failure of the transverse septum of the diaphragm to fuse with the costal arches, thus forming the Morgagni foramen or sternocostal hiatus [2,3]. Larrey described surgical approach to the pericardial cavity through the anterior diaphragmatic defect on the left side in 1828. Being of similar anatomic origin, they are collectively referred to as “anterior diaphragmatic hernia of Morgagni–Larrey [4]. Most hernias are located on the right side, as the protection provided by the heart and pericardium makes left-sided locations particularly rare [5].

Anatomically, the Larrey variant specifically involves the left sternocostal triangle, a congenital weak point of the anterior diaphragm analogous to the right-sided Morgagni defect; in this space multiple abdominal viscera such as stomach, colon, spleen, and omentum may herniate, and this anatomical complexity contributes to the variable clinical presentations and underscores the importance of detailed imaging and timely surgical repair. They account for less than 5% of all congenital diaphragmatic hernias.

In adults, these hernias are often diagnosed late, as patients are asymptomatic or present with nonspecific respiratory, digestive, or cardiovascular symptoms [6]. Chest X-rays may suggest the diagnosis, but they remain nonspecific and depend largely on the hernia contents [5]. Computed tomography (CT) is the gold standard examination, providing accurate visualization of the diaphragmatic defect, identification of herniated organs, and detection of complications such as incarceration or strangulation [7].

Our observation is of particular interest because of its left-sided location and, above all, the extent of its hernial contents, including the entire stomach, spleen, transverse colon, omentum, and tail of the pancreas. This case illustrates the rarity of left sided Morgagni-Larrey hernias and highlights the importance of imaging in surgical planning [8].

Case presentation

We report the case of a 17-year-old patient, a chronic smoker and user of volatile solvents, admitted to the emergency department with sudden-onset abdominal pain and respiratory distress of 12 hours’ duration. Clinical examination revealed epigastric guarding and dullness over the left lung base.

A frontal chest X-ray, performed as a first-line investigation in the emergency department, revealed a large opacity occupying the left hemithorax, causing cranial displacement of the ipsilateral lung parenchyma (Fig. 1). Due to diagnostic uncertainty, a contrast-enhanced chest, abdominal, and pelvic computed tomography (CT) scan was performed. This confirmed the presence of a left anteromedial diaphragmatic defect (Fig. 2, Fig. 3), with intrathoracic herniation of several abdominal viscera: completely ascended and distended stomach, spleen, transverse colon, omentum, and pancreatic tail (Fig. 4). The CT scan allowed the defect to be precisely characterized and possible complications, such as volvulus, gastric perforation, or ischemia of the herniated organs, to be ruled out.

Fig. 1.

Frontal chest X-ray in standing position showing a large opacity in the left lower thoracic projection, with air fluid level, pushing the mediastinum to the right and the ipsilateral lung upward.

Fig. 2.

Computed tomography (CT) scan of the chest, abdomen, and pelvis (TAP) with intra-venous (IV) contrast at the portal phase, multiplanar reconstructions (MPR) showing the left anteromedial diaphragmatic defect.

Fig. 3.

Computed tomography (CT) scan of the chest, abdomen, and pelvis (TAP) with intra-venous (IV) contrast at the portal phase in the sagittal and coronal views: direct visualization of the left anteromedial diaphragmatic defect (blue arrows), site of intrathoracic herniation of the abdominal viscera, and the left diaphragm (red arrow).

Fig. 4.

Computed tomography (CT) scan of the chest, abdomen, and pelvis (TAP) with intra-venous (IV) contrast at the portal phase, multiplanar reconstructions (MPR) highlighting the intrathoracic hernia contents consisting of multiple abdominal viscera, including the stomach (S), tail of the pancreas (P), transverse colon (C), and spleen (R) situated above the diaphragm (green arrow).

Given the size of the hernia and the risk of progression, emergency surgery was performed. Intraoperative exploration via median laparotomy combined with anterolateral thoracotomy confirmed the imaging findings, allowing complete reduction of the herniated viscera and primary closure of the diaphragmatic defect.

The postoperative course was uneventful, with complete resolution of symptoms.

Discussion

Morgagni-Larrey hernia is the rarest form of congenital diaphragmatic hernia, accounting for less than 5% of cases [9]. Left-sided localization is extremely unusual due to the protection afforded to the heart and pericardium [5]. Large forms, which simultaneously include hollow viscera and solid organs, are even rarer, making our observation particularly notable [8]. Although some patients present symptomatically, Morgagni hernias are often diagnosed incidentally on cross-sectional imaging performed for unrelated reasons, underscoring the importance of vigilance and accurate radiologic interpretation even in asymptomatic individuals [10].

Morgagni-Larrey hernias, particularly when identified in infancy or early childhood, exhibit a high frequency of association with other congenital anomalies, with the incidence ranging between 34% and 50%. The most frequently reported associations include cardiac defects (25%-60%) and trisomy 21 (15%-71%). The specific link with trisomy 21 is hypothesized to involve defective dorso-ventral migration of rhabdomyoblasts, caused by increased cellular adhesiveness, which may also explain the higher risk of recurrence after surgical repair in these patients. Other identified malformations include intestinal malrotation, anorectal anomalies, omphalocele, skeletal defects, and pentalogy of Cantrell [2].

Imaging plays a central role in diagnosis and management. Chest X-rays may reveal opacity of the hemithorax or air-fluid levels, but their specificity is limited [5]. Computed tomography (CT) is the gold standard examination, providing accurate visualization of the diaphragmatic defect, identification of herniated organs, and detection of complications such as incarceration or strangulation [7]. In our case, the CT scan confirmed the presence of all herniated organs, including solid organs such as the spleen and tail of the pancreas, which was essential information for planning the surgical procedure. MRI may be considered in certain situations, but its usefulness is limited compared to CT, especially in acute presentations [11]. Early diagnosis is particularly valuable because even asymptomatic hernias carry a risk of future complications such as strangulation, obstruction, or cardiopulmonary compromise, which are major indications for surgical intervention [12].

The differential diagnosis for a late-presenting congenital diaphragmatic hernia is extensive due to its varied clinical and radiological appearances. When a bowel loop is visible in the thoracic cavity on a chest radiograph, the differential includes a pericardial cyst, loculated pneumothorax, or a hiatal hernia. If the hernia contents appear as solid structures, such as omentum or liver, alternative diagnoses like atelectasis, pneumonia, a pericardial fat pad, intrathoracic lipoma, bronchial carcinoma, or an atypical mediastinal tumor must be considered. Computed tomography remains the examination of choice, offering a correct identification rate of 100% by accurately distinguishing fat densities and vascular patterns [2]. Ultimately, the Morgagni-Larrey entity should be systematically included in the differential diagnosis for any patient presenting with a combination of gastrointestinal disturbances and respiratory distress [4].

Surgery remains the treatment of choice, even in the absence of symptoms, in order to prevent complications from developing. The approach (laparotomy, laparoscopy, or thoracotomy) is chosen based on the size of the defect, the complexity of the hernia contents, and the preferences of the surgical team [12]. Symptomatic patients (with pain, respiratory symptoms, or signs of obstruction) and those with evidence of organ compromise on imaging are universally recommended for repair, while incidental lesions may also be repaired electively due to the documented risk of future life-threatening events [13].

In our observation, surgical exploration confirmed the radiological data and allowed complete reduction of the hernial contents and closure of the diaphragmatic defect. This case highlights the rarity of large Morgagni-Larrey hernias and underscores the crucial importance of imaging, particularly CT, for diagnosis, surgical planning, and prevention of serious complications. It also illustrates the need for multidisciplinary management and high clinical vigilance.

Conclusion

Morgagni-Larrey hernia, especially when located on the left side and containing voluminous visceral contents, remains an uncommon entity. Imaging, particularly computed tomography, is essential for making the diagnosis, accurately characterizing the hernia contents, and guiding the therapeutic strategy. Surgical management remains the standard treatment, even in the absence of complications, in order to prevent the risks of incarceration or strangulation. This case highlights the importance of early recognition and appropriate management of these uncommon conditions.

Patient consent

Written informed consent was obtained from the patient’s family for the writing and publication of this article and accompanying images.