The estimated rate of occurrence of congenital diaphragmatic hernia varies from 1:2000 to 1:4000 live births. Though thousands of such cases are reported during infancy, few reports describe adult patients diagnosed with Bochdalek hernia. Usually, these hernias become evident during the neonatal period, through symptoms and signs of respiratory distress. However the most frequent symptoms found in adult patients are slight respiratory and digestive symptoms. It is also possible for these hernias to be asymptomatic. Here we report a case of mild dyspnea within a congenital posterolateral diaphragmatic hernia.

Bochdalek hernias, first described by Bochdalek in 1848, are characterized by a congenital defect on the posterolateral region of the diaphragm without hernia sac. They are generally discovered in neonates, but is rarely reported in adults. The aetiology factor of Bochdalek hernias is unknown, but we know that the occurrence of this disease is due to the failure of closure of the pleuroperitoneal canal during the ninth to tenth week of gestation [1]. According to reported literatures, Bochdalek hernias are associated with other congenital anomalies in 25-57% of cases and with chromosomal disorders in 10-20% of cases. In our case, the patient has a pair of supernumerary breasts and the pulmonary hypoplasia of the lower-left lobe. The diagnosis of a Bochdalek hernia in adults is not easy and it is commonly misdiagnosed. Unlike infants who show with respiratory distress early, the most frequent symptom in adults is mild discomfort and 25% of adult patients are asymptomatic. Consequently, many patients are merely treated according to their symptoms. No more diagnostic investigation is pursued due to the lack of awareness of the disease. Our patient also had an experience of misdiagnosis and she was treated for bronchitis for one year until she was admitted to our hospital. Thus it is important for us to keep the disease in mind. When clinical suspicion of Bochdalek hernia is produced, multiple imaging modalities are available. X-rays are the most general imaging study performed to evaluate the diaphragm and thoracic cavity. When chest radiographs are indeterminate, Spiral CT and MPRs are a good choice to offer us more information. The differential diagnosis of a huge mass in the left thoracic cavity is congenital diaphragmatic eventration. Diaphragmatic eventration is characterized by the displacement of all or a part of the intact diaphragm. By contrast, the diaphragm of a patient with a Bochdalek hernia is interrupted and has a defect on it. On the other hand, diaphragmatic eventration does not always need surgical therapy. However for congenital diaphragmatic hernia, surgical repair should be performed as soon as the diagnosis is confirmed in order to avoid serious complications. The principal management of Bochdalek hernias include reducing the abdominal organs and repairing the defect. It is controversial as to which approach is the best. Scholars who choose thoracotomy praise the convenience of separating adhesions between thoracic contents and the hernia sac, although 62% to 90% of Bochdalek hernias do not have hernial sac, however the presence of sac is not the rule [2]. Those who advocate a laparotomy claim that the abdominal approach is better than thoracotomy for dealing with possible complications such as malrotation, obstruction, strangulation and perforation of abdominal viscera [3]. Minimal invasive surgeries including thoracoscopic repair and laparoscopic repair of Bochdalek hernia are also reported [4]. Our patient underwent a thoracotomy in consideration of the presence of adhesions between thoracic contents and pleura.

For Bochdalek hernias, correct diagnosis and early treatment is significant to avoid the occurrence of serious complications. To improve the quality of medical treatment for Bochdalek hernias in adults, more cases will need to be reported and long-term follow up should proceed.

Written informed consent was obtained from the patient for publication of this case report and any accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal.