Nontraumatic Liver Herniation Mimicking a Lower Lobe Lung Mass

Abstract

INTRODUCTION: Spontaneous diaphragmatic herniation is a rare type of acquired diaphragmatic hernia without any history of trauma. (1) We describe a case where a non-traumatic liver herniation through diaphragm was observed mimicking a lower lobe lung mass. CASE PRESENTATION:A 54-year-old female without prior thoraco-abdominal trauma was seen in the clinic because of growth of 2 right lower lobe lung nodules. These nodules were initially noted incidentally on CT scan in August 2009 and measured 1.5 cm x 2.8 cm and 0.9 cm x 1.3. They remained stable on CT scan and PET performed in 2010. Patient was lost follow-up after that until she had a CT scan in March 2019 because of concern of pneumonia and it was noted that the lung nodules have increased in size to 2.8 cm x 4.1 cm and 1.1 cm x 1.4 cm. The patient was otherwise asymptomatic. A PET scan was obtained which showed hypermetabolic nodules with maximum SUV of 3.29 and 1.4 for the larger and smaller nodule respectively. Radiographic appearance as well as the growth pattern was consistent with low-grade malignancy like carcinoid tumor. We performed robotic thoracoscopy with plan for wedge resection and possible completion lobectomy. Gross inspection of the thoracic cavity revealed abnormal mass on the dome of the diaphragm with appearance like liver. It was noted to be lying in the oblique fissure and corelated with the position of larger nodule seen on CT scan. There was a second area of thinned-out area of the diaphragm where a small nodule was noted pushing on the diaphragm with appearance like liver consistent with location of smaller lesion on CT scan. A Tru-Cut needle biopsy showed that it was benign liver tissue. The decision was made not to proceed with any diaphragmatic repair or reinforcement with mesh as this was an asymptomatic herniation through diaphragm and the liver was fibrosed to the diaphragm protecting from any intestinal herniation.DISCUSSION: A review of literature revealed that there are 28 reported cases spontaneous diaphragmatic rupture (SDH) and of those only 10% had liver herniation. SDH is caused by events that increase intra-abdominal pressure like complicated labor, intense physical exercise, psychiatric illness, and cough secondary to pertussis. Another predisposing factor for SDH is congenital diaphragmatic defect which creates an area of weakness and increases the likelihood of herniation secondary to increased intra-abdominal pressure. SDH has also been described in association with other conditions like Ehler-Danlos Syndrome (EDS) and endometriosis because of weakness of diaphragmatic tissue. CONCLUSIONS: Our case was unique because the patient had asymptomatic SDH presenting as a lung mass without any history of etiologies leading to increased intra-abdominal pressure or weakness of diaphragm. Liver herniation through diaphragm can be managed without surgical repair if liver if fibrosed to diaphragm.