Ectopic intrathoracic liver tissue is extremely rare. Studies are mainly limited to case reports. In the vast majority of reported cases, a diagnosis of intrathoracic liver tissue was made either after a thoracic surgery or during a postmortem examination. However, once included in differential diagnosis, surgical intervention or biopsy procedures may be avoided with optimal diagnostic approach. In the present study, we conducted a literature review and proposed a new classification method for accessory liver within the thoracic cavity. This approach may provide a better understanding of underlying pathophysiology and aid in determination of optimal diagnostic modality and clinical management of such cases. According to our literature review, type II ectopic liver is the most common subtype followed by types I and III. All types can be definitively diagnosed with imaging modalities. On the other hand, it is important to prevent patients, particularly children, from unnecessary radiation exposure during performance of sophisticated diagnostic imaging modalities. Ultrasound is a safe, low-cost and accessible imaging modality that has not been previously reported in diagnosis of this entity. With addition of Color Doppler Imaging, ultrasound may allow for diagnosis with high precision in types I and II, as demonstrated in the present study. Based on long-term follow-up of a case reported here, this study also illustrates the natural course of this entity via non-operative management. This approach may prevent an unnecessary surgical intervention.
Keywords: Accessory liver; Anatomical variation; Thorax; Ultrasound.