Heterotopic supradiaphragmatic livers are rare. A total of 23 cases of primary supradiaphragmatic livers have been reported in the literature. The clinical presentations of heterotopic supradiaphragmatic liver are variable. The simultaneous detection of intrathoracic accessory liver and pulmonary sequestration is extremely rare, and only one case has previously been reported. It is difficult to make a correct diagnosis preoperatively. We presented a 53-year-old woman with complaints of an intermittent, productive cough and dyspnea for two months that was refractory to medical treatment. She had no previous history of trauma or surgery. A chest radiograph only showed a widening of the mediastinum. Contrast-enhanced computed tomography of the chest revealed a well-circumscribed homogenous soft-tissue mass, approximately 4.35 cm × 2.5 cm × 6.14 cm in size, protruding through the right diaphragmatic crura to the right pleural cavity, attached to the inferior vena cava, esophagus and liver. There was no conclusive diagnosis before surgery. After the operation, we discovered that this patient was the first case of a supradiaphragmatic heterotopic liver, which passed through the inferior vena cava foramen and was coincidentally combined with an intralobar pulmonary sequestration that was found intraoperatively. We discussed its successful management with surgical resection via a thoracic approach and reviewed the published literature.

Heterotopic supradiaphragmatic livers are exceedingly rare. Abnormally positioned liver tissues have been described, but these are more commonly observed in the abdominal cavity than in the thoracic cavity. This is one of the first examples of a supradiaphragmatic heterotopic liver in the literature[1]. The clinical presentations of heterotopic supradiaphragmatic livers are variable. The simultaneous detection of an intrathoracic accessory liver and pulmonary sequestration was reported as the first and only one case in 2008[2]. The etiology of an introthoracic liver coinciding with pulmonary sequestration is not well known. Herein, we describe the first case of a supradiaphragmatic heterotopic liver passing through the inferior vena cava foramen and coincidentally combined with intralobar pulmonary sequestration.

A 53-year-old woman was referred to our center from an outside clinic complaining of intermittent productive cough and dyspnea over the previous 2 mo that was refractory to medical treatment. She denied any previous history of trauma or surgery. There were no positive findings on the physical examination. A chest roentgenogram only showed a widening of the mediastinum. Despite adequate medical treatment, her symptoms persisted. Contrast-enhanced computed tomography (CT) of the chest revealed a well-circumscribed homogenous soft-tissue mass, approximately 4.35 cm × 2.5 cm × 6.14 cm in size, protruding through the right diaphragmatic crura to the right pleural cavity attached to inferior vena cava (IVC), esophagus and liver (Figure 1). There was no pulmonary consolidation or other abnormalities of the bilateral lungs in imaging studies. In addition, the esophagram showed no submucosal lesions. Based upon these imaging findings, the tumor at middle mediastinum and right pleural cavity provoked discussion of a surgical resection.

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Figure 1 Computed tomography of the patient’s chest showing a well-circumscribed soft-tissue mass (white arrow), approximately 4. 35 cm × 2.5 cm × 6.14 cm in size, over the middle mediastinum, with mild compression on the esophagus. A: Sagittal view; B: Transverse view.

Video-assisted thoracoscopic surgery (VATS) through the right chest wall was performed initially, and the operative findings revealed hypoplasia and regional hyperemic changes at the pleural surface of the right lower lobe (RLL) of the lung, with two obvious aberrant vessels from the right hemidiaphragm. After dissecting the visceral pleura and the tense capsule, the inferior pulmonary vein was identified, and a well-defined, red-brown, 7 cm × 4.5 cm × 2 cm solid mass abutting the IVC from the cardiophrenic angle of the right hemidiaphragm was found (Figure 2). Due to the limited area of the sequestrated lung of RLL, a wedge resection with an Endo-GIA staple instrument was performed. Due to the indeterminate nature of the mass and the location close to the IVC, we converted the operation to a right limited thoracotomy. The tumor was biopsied, and the frozen section showed reactive liver tissue with cirrhotic change. Therefore, we resected the tumor, which was extruding from the right pleural cavity, and then repaired the foramen of the IVC. The pathologic report showed liver tissue with chronic inflammation and cirrhotic changes (Figure 3). The patient had a good recovery after the surgery and was discharged home one week later. CT-angiography of the chest was conducted after the surgery to retrospectively evaluate the pulmonary sequestration (Figure 4). The aberrant arteries were identified from the abdominal aorta.

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Figure 2 Intraoperative picture. Intraoperative picture showing the exposure of the abnormal lung with hypervascularity at the posterior basal segment (A) (short arrow) and aberrant vessels (B) (long arrow) passing through diaphragm. The mass (C) (dotted arrow), covered by the sac, abutted the inferior vena cava (IVC), posterior chest wall and diaphragm. After dissecting the covering sac, a herniated liver (D) (dotted arrow) was impressed.

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Figure 3 Cutting surface of the resected specimen showed liver tissue with cirrhotic changes.

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Figure 4 Postoperative computed tomography angiography confirmed the cutting end of the aberrant vessels. A-D: Showed the trend of the aberrant vessel. The remnant aberrant vessel from abdominal aorta (long arrow), engorged aberrant vessels (short arrow).

Supradiaphragmatic, intrathoracic liver tissue is very rare. A total of 23 cases of intrathoracic liver have been reported in the literature[1-23]. We introduced a rare case of an accessory liver lobe herniation from the IVC foramen to the right pleural cavity, combined with an intralobar sequestration of the RLL. This is the second case of a simultaneous detection of intrathoracic liver and pulmonary sequestration. The first case was reported in 2008, and the multiple cystic lesions in the right upper lobe, which were thought to constitute a congenital cystic malformation, were in fact an intralobar pulmonary sequestration[2]. However, the sequestrated lung of the above case was not typically located at the lower lobe, and the aberrant vessels were not visible. We found the sequestrated lung during the operation and then followed up with CT angiography to identify the feeding arteries of the sequestrated lung. Table 1 showed that seven cases (7/24, 29%) had diaphragmatic defects, and only the present supradiaphragmatic liver passed through the IVC foramen. There were 18 cases (18/24, 75%) associated with right-side intrathoracic livers. The majority of the intrathoracic ectopic or accessory liver lobes were connected to the orthotopic liver by means of a small pedicle that pierced the diaphragm or passed through a small hiatus[1,9,12,15-17,19,21]. In the presenting case, the caudate liver connected with the main portion of the liver just beneath the IVC. However, the pre-operative CT scan of the chest was not able to demonstrate this clearly, and it was difficult to make appropriate diagnosis before the operation.

Such events are most often found in the vicinity of the liver, such as in the gallbladder, spleen, pancreas, umbilicus, adrenal gland, or omentum, and usually some connective tissue or mesenteric attachment to the liver remains[10]. Very rare cases involving the thoracic cavity can be found. Of those cases reported in the literature, almost all were misdiagnosed, most often as a pulmonary tumor and sometimes as pulmonary sequestration or hydatid cyst[12,21]. The misdiagnosis of such cases often leads to potentially unnecessary or inappropriate thoracotomies and the resection of the ectopic liver tissue. Although heterotopic liver tissue may be acquired secondary to trauma or diaphragmatic hernia repair, previous reports have speculated that this condition mostly represents a developmental defect of the septum transversum[10]. The most probable explanation is the development of an accessory liver lobule, with atrophy or regression of the original connection to the abdominal liver[10]. Retrospectively re-examining the clinical evidence, we found at least two signs implying the possibility of an accessory liver lobe in the thoracic cavity. First, the mass was homogeneous, with a density similar to that of a normal liver. Second, the mass was adjacent to the hemidiaphragm and connected to caudal lobe of liver through a defect of the right crus. An intrathoracic ectopic or accessory liver lobe is rarely of clinical significance[12,16]. Surgery is not always required for such a condition. However, the cases reported were almost always respected because of their inappropriate diagnoses. There were a few cases that did have symptoms, such as chest pain, hemoptysis, or dry cough[12,21], that may or may not have been related to the underlying condition. Such abnormal tissue could lead to further liver pathologies, such as cancer, hepatitis, and tissue ischemia secondary to torsion[21]. To avoid malignant changes in this loco-regional cirrhosis of the liver[24], surgical resection was the first choice for treatment.

Because heterotopic supradiaphragmatic livers are extremely rare and occur at tricky anatomic locations, it is difficult to make an appropriate diagnosis preoperatively. In our case, we also misdiagnosed the liver as a pulmonary sequestration before surgery. The intralobar pulmonary sequestration was found incidentally at the time of the operation because of the engorged aberrant vessels from systemic circulation; it was then divided by stapled Endo-GIA due to the small area of the sequestrated lung of the RLL. The pathological report of the sequestrated lung showed inflammation, mucus accumulation, microcystic changes and dilated lymphatic channels. Pulmonary sequestration is a rare congenital malformation of the lower respiratory tract[25] that consists of a nonfunctioning mass of lung tissue that lacks normal communication with the tracheobronchial tree and receives its arterial blood supply from the systemic circulation[26]. There are intralobar and extralobar forms, the former of which is embedded in a normal lung and the latter, separated from the adjacent lung by its own visceral pleural investment[27]. Misdiagnosis or delayed diagnosis of such pulmonary malformations results in unnecessary treatments and hospitalizations, as well as in frequent, recurrent infectious complications. The definitive treatment for sequestrated lung diseases is surgical resection, which is curative and has low morbidity and mortality rates[28].

In addition, a multi-detector spiral CT scan with multi-planar reconstruction and magnetic resonance imaging can also reveal the location of the mass and its relation to the normal liver parenchyma[19]. Furthermore, with enhanced scanning and hepatic angiography, if the hepatic vessels extend to the mass, the diagnosis of an accessory liver lobe is more definitive[19]. Thoracoscopy is also effective in the diagnosis of the intrathoracic accessory liver lobes in suspected patients, and conveniently, the lesion might be resected with minimally invasive procedures under thoracoscopy, if the connecting pedicle is not too large in size[22]. If an intrathoracic mass is suspected to be a pulmonary or chest wall benign tumor, abnormal liver tissue should enter the scope of a differential diagnosis to avoid potentially unnecessary or inappropriate surgical interventions[22]. Table 1 revealed that 19 cases underwent thoracotomy, and only two had laparotomy. We attempted to use VATS with the removal of the mediastinal tumor at first, but we finally converted to thoracotomy because of the unclear anatomic view and our diminished confidence.

We presented a very interesting case of supradiaphragmatic heterotopic liver coincidentally combined with intralobar pulmonary sequestration. The ectopic liver was the first case to pass through IVC foramen. To our knowledge, these two anatomic abnormalities are congenital and developmental problems and may constitute a specific type of syndrome.