Management of Benign Tumors
The management of BLT is still evolving because of several advances: the improvement in diagnostic radiological imaging, which should reduce the prevalence of unnecessary liver resections; recent histopathological and biomolecular findings, particularly concerning adenomas; the widespread use and safety of laparoscopic surgery; and improved identification and knowledge of the multiple lesions. The main challenge is to determine the indications for surgery, considering as usual, the risk-benefit ratio.
In fact, four types of surgery can be identified: life-saving surgery for emergency situations, symptomatic surgery for patients with pain or discomfort, preventive surgery for tumors presenting a high probability of complications, and diagnostic surgery for when the diagnostic workup fails to distinguish benign from malignant tumors. In the first two situations, the discussion concerns the modality of surgery; in the last two situations, the discussion focuses on clear indications.
Indications for Surgery
Bleeding Tumors This clinical feature consists of an acute onset of abdominal pain related to a subcapsular giant hematoma and/or hemoperitoneum with hemorrhagic shock, generally caused by spontaneous rupture of an adenoma, or in exceptional cases, a hemangioma.
The first step is appropriate resuscitation in a monitored setting. Usually, the patient can be stabilized and a CT scan performed to make the diagnosis. If there is no evidence of continued bleeding on imaging or based on clinical improvement, the indication for selective arterial embolization is controversial. Bleeding may sometimes spontaneously stop, and delayed surgery may be performed under nonacute conditions after resorption of the hemoperitoneum or the subcapsular hematoma. If the patient remains hemodynamically unstable, arterial embolization is the initial treatment of choice as emergent operative exploration is highly morbid with high rates of mortality. In cases of misdiagnosis or clinical instability, a laparotomy may be emergently performed and the ruptured tumor intraoperatively discovered. In this situation, surgical resection should be performed only if a minor hepatectomy can be performed such as a left lateral sectionectomy or resection of a pedunculated tumor. Otherwise, perihepatic packing may be performed, followed by arterial embolization, as a major hepatectomy is not recommended because of a mortality rate of near 8%.
Some authors recommend embolization to support the delayed surgery because embolization reduces the size of the adenoma so that hepatectomy may be minimized in extent, or avoided altogether because of major or complete regression of the tumor.
Solitary Symptomatic Tumors The symptomatic tumors are usually large lesions. The indications for surgery, which include complete removal of the solid lesion, should be discussed based on the severity of symptoms and the risks of surgery.
For cystic tumors, percutaneous aspiration may serve as a "diagnostic tool" proving that the symptoms are commensurate with the cyst; however, this procedure is not a valid treatment. Laparoscopic fenestration or deroofing of the cyst is the gold standard. This technique involves wide excision of the roof of the cystic wall so that the cyst is opened into the peritoneum. Omentoplasty is useful to avoid closure of the cyst. Resection might be indicated in selected cases such as the atrophy of a lobe or the doubtful diagnosis of cystadenoma. Histological examination of the cystic wall is mandatory for excluding the presence of a rare cystadenoma. Alternative surgical treatment consists of aspiration-sclerotherapy with alcohol under US guidance. After removal and analysis of the fluid, excluding bile staining and (for some authors) a contrast cystogram, instillation of ~30% of the cyst volume with alcohol is performed, and kept in place for 2 hours. For medium-large cysts, this procedure appears to be efficient and minimally invasive; however, not as effective as laparoscopic deroofing.
Solitary Asymptomatic Tumor Hemangioma, FNH, and cysts, if diagnosed with certainty by imaging, must be managed conservatively regardless of their size. No follow-up is recommended because even if the tumor size increases, surgery will not be indicated if the patient remains asymptomatic. Unwarranted and prolonged follow-up may induce anxiety and symptoms in the patient. No change in lifestyle is necessary for any of these lesions, such as refraining from contact sports or terminating OC use. The only condition to be discussed is the desire for pregnancy in a woman presenting with a large subcapsular hemangioma. Some investigators advocate preventive surgical resection because of the rare risk of rupture during pregnancy.
For asymptomatic adenomas, surgery must be discussed in terms of a preventive strategy because of the risks of bleeding and malignancy. Indeed, routine surgery for adenomas is controversial, and conservative management may be recommended in many cases. Much data are currently available concerning the genetic and pathological characterization of these BLT and the real risk of complications. It has been shown that the risk of hemorrhage (20-40%) is greater than the risk of malignancy (10%).[84,85] There is a clear relationship between these risks and two types of data: the size of the tumor and the genetic and pathological type of HCA. The latter may be determined by MRI or diagnosed by biopsy. The risk of hemorrhage is higher for HCA > 5 cm and inflammatory HAs, and the probability of malignancy is higher in HCA > 5 cm, and linked to the β-catenin mutation.
Nonetheless, it should be stressed that some small adenomas bleed (12%), and it may be difficult to distinguish between adenoma and HCC on imaging and even in histological specimens. Therefore, treatment recommendations can be summarized as follows: For small adenomas (< 5 cm) in females, discontinue OP and attempt to characterize the tumor (as steatotic or inflammatory) based on MRI. If the tumor is steatotic, then follow-up is justified (every 6 months, by US). If the tumor is inflammatory or if it increases in size, then discuss surgery with the patient. Otherwise, observation appears to be justified. If pregnancy is planned, discuss surgery or radiofrequency ablation. For patients with large adenomas (> 5 cm), surgery should be scheduled. For adenomas of any size in males, surgery should be proposed.
Multiple Lesions Management of the multiple forms of benign tumors is difficult because surgical clearance is often impossible and because no clear recommendations are available.
In cases of hemangiomatosis, the same rules as for solitary hemangiomas are applied: only symptomatic forms require surgery and follow-up is unnecessary. Multiple FNHs are usually asymptomatic and also require no follow-up. The most delicate issue is the management of adenomatosis. Surgical management depends on the type of adenomatosis (large adenomas or diffuse adenomatosis presenting as multiple small nodules), the histological subtype, the symptoms, and the patient. Resection of the largest or most complicated adenomas may be performed, with or without intraoperative radiofrequency ablation, while small, uncomplicated lesions may be surveyed. Arterial embolization has been applied to progressive adenomatosis with good results. In the rare cases of iterative complications or proven malignant transformation, liver transplantation should be discussed.
In PCLD patients, the indications for surgery depend only on the severity of symptoms. The surgical options consist of fenestration, liver resection, and liver transplantation. The procedure depends on the type of the disease based on the Gigot classification and the presence of renal dysfunction. Before considering resection or transplantation, which are potentially morbid procedures, alternative medical management should also be discussed for Gigot type II and III disease (e.g., somatostatin, mTOR inhibitors, or hepatic embolization). Despite the absence of liver dysfunction, transplantation is often the cure especially for patients with end-stage renal disease.
Principles of Surgery
Which Approach Should Be Used? The development of laparoscopic surgery has changed the approach to treatment of benign liver tumors. Currently, laparoscopic liver resection is feasible and safe when performed by experienced surgeons. The trend is moving from limited hepatectomy involving the anterior segments to major hepatectomy and resection of any segments of the liver.
The most beneficial aspect of laparoscopy is a reduction of the invasiveness of liver resection in terms of postoperative pain and cosmetic outcomes, which is important in the population that is usually affected. However, there is a dangerous and unjustifiable trend toward resecting an increasing number of BLT since the introduction of laparoscopy, and some series report a questionably high rate of diagnostic surgery or preventive surgery. Nonetheless, the first rule of surgical management is the safety of the patient, regardless of the approach.
In appropriate hands, laparoscopy is the gold standard for the management of hepatic cysts, small benign tumors located in the left lobe, or in anterior segments of the liver (< 5 cm) or pedunculated masses. Laparoscopy is also an excellent approach for multiple benign lesions: it allows complete exploration of the parenchyma, and multiple biopsies of various nodules and of the nontumorous liver. In large tumors requiring major hepatectomies, some authors have demonstrated the feasibility of laparoscopy. However, open surgery remains the gold standard, especially if the tumors are closely adherent or adjacent to major vessels. Major laparoscopic hepatectomy should be reserved for trained surgeons in specialized centers.
Which Procedure Should Be Employed? Surgery for large, benign, solid tumors may be difficult because of the size of the tumor, the peripheral vascularization, or compression of the hepatic veins or vena cava. A right subcostal incision is usually appropriate, but for massive tumors located close to hepatic veins, there should not be any hesitation to perform a larger incision, including a right thoraco-abdominal approach. Intraoperative US is mandatory to detect small lesions and to study the limit of the tumor, thus guiding the surgical plan. The Pringle maneuver or selected devascularization of the tumor must be performed to reduce the blood inflow so that the tumor is more easily mobilized and enucleated—which is obvious in cases of large hemangiomas or FNHs. Enucleation of adenomas may be hazardous because it can be difficult to identify the limits of the tumor; indeed, a margin is preferable in cases of focal malignant transformation. In some cases, total vascular exclusion is mandatory to control subhepatic bleeding. Nonetheless, in benign disease, removal of the normal liver parenchyma must be kept to a minimum.
The Role of Liver Transplantation Benign liver tumors constitute a rare indication for liver transplantation, which is understandable given the usual excellent prognosis of these tumors compared with the complexities of transplantation. Moreover, liver function is always preserved. Therefore, transplantation should be discussed in terms of preventive or symptomatic surgery for extreme cases. Concerning solid tumors, the indications include a solitary, giant, unresectable, solid tumor with severe symptoms[93,94] or with underlying liver disease; and multiple benign tumors with serious untreatable complications, such as iterative hemorrhage or the high suspicion or occurrence of malignant transformation in adenomatosis. These indications are anecdotal and should remain so. For example, in Europe, less than 50 transplantations have been performed for adenomatosis (unpublished data). A larger body of experience exists regarding liver transplantation for polycystic liver disease because of the associated kidney disease. Approximately 45% of these patients undergo a combined liver kidney transplant with good—but not excellent—results: 5-year survival of 68.7% in LT and 75.5% in CLKT.
Transplantation is technically difficult in these cases, especially if the patient has undergone previous surgical procedures; therefore, some authors advocate early consideration of LT in a selected group of patients.
Semin Liver Dis. 2013;33(3):236-247. © 2013 Thieme Medical Publishers