Follow-up of asymptomatic adult diaphragmatic hernia: should patients with this condition undergo immediate operation? A report of two cases

BACKGROUND Asymptomatic diaphragmatic hernia is generally thought to be rare among adults. We present two different types of asymptomatic diaphragmatic hernia diagnosed with computed tomography (CT) and discuss treatment strategies. CASE PRESENTATION Case 1: A 37-year-old woman was diagnosed with catamenial pneumothorax in the right diaphragm. Partial resection of the diaphragm and lung was performed using a linear stapler. She was asymptomatic after the operation and gave birth 2 years later. After delivery, she experienced recurrent pneumothorax, and CT revealed a right diaphragmatic defect with herniation of a part of the liver into the thorax. An iatrogenic diaphragmatic hernia was diagnosed. There has been no change in the size of the hernia and no symptoms due to the diaphragmatic hernia for more than 3 years after it was diagnosed. Case 2: A 75-year-old woman was previously diagnosed with rectal cancer and had undergone surgery after chemoradiotherapy. One year after surgery, herniation of a 3 × 1.3-cm section of retroperitoneal fat tissue into the left thoracic cavity was observed incidentally at a follow-up CT and was diagnosed as an adult Bochdalek hernia (BH). We reviewed the patient's past CT findings and confirmed that the same finding had been present since the first scan. A wait-and-see approach was chosen because there had been no change in the size of hernia, there were no symptoms, the patient was elderly, and there was a high risk of recurrence of the rectal cancer. She has had no symptoms to date, and careful follow-up has been performed. CONCLUSIONS There are few reports of asymptomatic adult diaphragmatic hernia. Although symptomatic diaphragmatic hernia is generally treated surgically, there are cases in which a wait-and-see approach has been applied, such as our asymptomatic cases.