Iatrogenic injury accounts for the second most common cause of acquired diaphragmatic hernias after penetrating trauma. An increased incidence of these hernias has been observed with the widespread use of laparoscopic surgery. We present the case of a 65-year-old woman who initially underwent sigmoid resection for an adenocarcinoma and a subsequent liver resection for metastasis. She was noted to have a left lower lobe pulmonary nodule on surveillance computed tomography, for which she underwent a mini-thoracotomy for a planned resection. At the time of surgery, the pulmonary nodule was discovered to be a diaphragmatic hernia, most probably of iatrogenic origin. We discuss the difficulty in diagnosis given her history and the location of such a lesion. Iatrogenic diaphragmatic hernias are becoming increasingly common given the increased use of laparoscopy. The majority of them are left-sided owing to the liver protecting the right hemidiaphragm. We present the case of a 65-year-old woman who was referred to our service for consideration for resection of a solitary pulmonary nodule in the left lower lobe. She had previously undergone anterior resection for a sigmoid adenocarcinoma and laparoscopic liver resection for metastasis. At the time of surgery, no lesion was identified in the lung and the suspected pulmonary nodule was noted to be a diaphragmatic hernia. We discuss the challenges of diagnosing a small diaphragmatic hernia.
Case HistoryA 65-year-old woman was referred with a completely asymptomatic pulmonary nodule, discovered on surveillance computed tomography (CT). This was performed as part of her routine follow-up review for a previous sigmoid adenocarcinoma, for which she had undergone anterior resection in October 2012. Subsequently, in January 2013, she had undergone a laparoscopic partial left hepatic lobectomy for metastasis.CT of the chest in September 2013 revealed a suspected pulmonary nodule (17mm  21mm) in the left lower lobe just above the diaphragm (Fig 1A). CT ten months later showed no significant change in this lesion. The positron emission tomography (PET) showed a lesion in the left lower lobe abutting the diaphragm with a maximum standardised uptake value of 1.9 (Fig 1B). Despite the low uptake, this could still represent a pulmonary metastasis and she therefore underwent a left mini-thoracotomy for removal of this suspected nodule.At the time of surgery, the lung was thoroughly palpated but no pulmonary mass was identified. However, a small lesion on the diaphragmatic surface was noted. It measured approximately 2cm  2cm and appeared cystic in nature (Fig 2). Following further inspection, a defect of 0.5cm  0.5cm could be demonstrated in the diaphragm, directly underlying the lesion, and the mass was deemed to be a diaphragmatic hernia, most likely related to the previous abdominal surgery. The hernia sac was opened to reveal omental fat. A small phrenotomy was performed and the sac content was repositioned in the peritoneal cavity. The hernia sac was excised and the diap...