Diagnosis and treatment of hepatic angiomyolipoma

Hepatic perivascular epithelioid cell tumors: The importance of preoperative diagnosis

Accurate preoperative diagnosis is highly important for the treatment of perivascular epithelioid cell tumors (PEComas) because PEComas are mainly benign tumors and may not require surgical intervention. By analyzing the causes, properties and clinical manifestations of PEComas, we summarize the challenges and solutions in the diagnosis of PEComas.

Transcatheter arterial embolization followed by laparoscopic anatomic hepatectomy for spontaneous rupture of a giant hepatic angiomyolipoma: a case report

Hepatic angiomyolipoma is a rare and possibly cancerous mesenchymal tumor that consists of three components: blood vessels, smooth muscle cells, and adipose tissue. In this paper, we reported a case of a 36-year-old man who had a giant hepatic angiomyolipoma with spontaneous rupture and hemorrhage. The patient was admitted to our hospital with sudden upper abdominal pain for 3 h. A giant tumor was found in the left and caudate lobes of the liver, as well as significant blood collection around the liver and in the pelvis. Hemoglobin, liver function test results, and serum tumor maker levels were all within normal ranges. To prevent bleeding, emergency angiography and embolization were performed. During angiography, it was discovered that the tumor was supplied by the left hepatic artery and had a very rich internal blood supply. A massive left hepatic mass of about 11 cm in diameter was found bulging from the surface of the liver and rupturing there during laparoscopic exploration a week later. The rupture was strongly adhered to the smaller curvature of the stomach. The patient underwent laparoscopic left hemihepatectomy and caudate lobectomy, and the tumor specimen was brown, with clear boundaries with the surrounding normal liver parenchyma, and there were a large number of necrotic lesions inside the tumor. Histopathological results confirmed the mass as hepatic angiomyolipoma with negative resection margins. Immunohistochemical staining indicated that the tumor had positive homatropine methylbromide-45. After 13 months of follow-up, no tumor recurrence or metastasis occurred in the patient.

Hepatic angiomyolipoma, misdiagnosed as hepatocellular carcinoma

Perivascular epithelioid cell neoplasm (PEComa) is a rare type of tumor, and hepatic PEComa is even rarer. Its preoperative diagnosis is difficult, given the absence of specific clinical manifestations, often constituting an accidental finding, and the lack of a gold standard for identification using imaging studies. Instead, the diagnosis of hepatic PEComa is based on morphological and immunohistochemical features. We describe a case of an asymptomatic hepatic PEComa, angiomyolipoma type, which appeared in a middle-aged woman with chronic liver disease, during her follow-up and screening. Given the patient's context, human immunodeficiency virus-positive with chronic hepatitis C, and the similarities between the two tumors, the hepatic lesion was interpreted as hepatocellular carcinoma. The patient underwent surgical excision of the tumor, and the positive immunohistochemical staining for human melanoma black 45 and Melan A made the definitive diagnosis. In the absence of aggressiveness tumor markers, surveillance was decided. We also provide a literature review of these tumors.

Diagnosis and surgical treatment of a rare hepatic angiomyolipoma with internal hemorrhage

Although angiomyolipoma (AML) is commonly found in the kidney, its appearance in the liver is rare. The first hepatic AML was reported by Ishak in 1976. Since then, there have been various reports of AML. An AML is a tumour affecting adipocytes, muscle tissues, and blood vessels. Hepatic AML has been associated with tuberous sclerosis. Its spontaneous occurrence has also been noticed. It can have a varied presentation with some being asymptomatic, others presenting with a dull aching pain, while some with disastrous consequences due to rupture and torrential bleeding intra-abdominally. Herein, we present a case of a 47-year-old female with a large hepatic AML having an internal hemorrhage that caused changes in hepatic arteries. In our case, magnetic resonance imaging was unable to establish a diagnosis. Intraoperatively, AML caused dilatation and engorgement of vessels around the porta. Immediately post resection, vessel dilatation and engorgement were reduced on table. Another notable feature was that these changes caused no intra-operative or post-operative hemodynamic changes. We report a case of a huge hepatic AML with internal hemorrhage associated with perihepatic vascular changes having a successful surgical treatment.

Malignant perivascular epithelioid cell neoplasm in the liver: report of a pediatric case

Background

Perivascular epithelioid cell neoplasm (PEComa) in a child is very rare. We herein report the first malignant case of PEComa developing in the liver of a pediatric patient.

Case presentation

A 10-year-old boy visited a private clinic with prolonged fever of unknown etiology. Abdominal ultrasonography was performed to evaluate the fever’s origin, revealing a large tumor in the liver. He was thus referred to a nearby hospital to investigate the tumor further. Enhanced computed tomography (CT) showed a 6.8 × 5.9 × 10.5-cm solid lesion on S4 and S5. On magnetic resonance imaging (MRI), the tumor had a low signal intensity on T1 imaging and high signal intensity on T2 imaging, with partial diffusion restriction. ¹⁸F-fluorodeoxyglucose-positron emission tomography (FDG-PET) showed a marked uptake in the mass lesion with no evidence of metastasis. The patient was negative for all tumor markers, including AFP, CEA and PIVKA-II. The results of a needle biopsy suggested hepatocellular carcinoma. The tumor’s rapid growth suggested malignancy. Hepatic segmentectomy (S4 + S5 + S8) was performed. The tumor was resected en bloc with a margin. Microscopically, the tumor showed atypical spindle, polygonal or oval-shaped cells with a high nuclear grade, and vascular invasion. Immunohistochemistry was positive for alpha-smooth muscle antigen (α-SMA), human melanin black-45 (HMB-45) and melan A. The pathological diagnosis was malignant PEComa. In the 6 months after surgery, the patient complained of shoulder pain. MRI showed a dumbbell-shaped tumor at the 2nd thoracic vertebrae, which was confirmed to be bone metastasis of PEComa. After chemotherapy, including ifosfamide and doxorubicin, vertebrectomy was performed. Two years later, thoracoabdominal CT showed a 10-cm solid mass occupying the pelvis and a 15-mm nodule in the middle lobe of the right lung. Under a diagnosis of peritoneal and lung metastases, they were surgically removed and metastasis of PEComa was pathologically confirmed. Four months after the 2nd relapse, pelvic metastasis appeared again and mTOR (mammalian target of rapamycin) inhibitor was initiated. To our knowledge, this is the first report of malignant hepatic PEComa in a pediatric patient.

Conclusion

Although extremely rare, malignant hepatic PEComa can develop in a child.

Clinical characteristics and outcomes of patients with hepatic angiomyolipoma: A literature review

First reported in 1976, hepatic angiomyolipoma (HAML) is a rare mesenchymal liver tumor occurring mostly in middle-aged women. Diagnosis of the liver mass is often incidental on abdominal imaging due to the frequent absence of specific symptoms. Nearly 10% of HAMLs are associated with tuberous sclerosis complex. HAML contains variable proportions of blood vessels, smooth muscle cells and adipose tissue, which renders radiological diagnosis hazardous. Cells express positivity for HMB-45 and actin, thus these tumors are integrated into the group of perivascular epithelioid cell tumors. Typically, a HAML appears on magnetic resonance imaging (or computed tomography scan) as a hypervascular solid tumor with fatty areas and with washout, and can easily be misdiagnosed as other liver tumors, particularly hepatocellular carcinoma. The therapeutic strategy is not clearly defined, but surgical resection is indicated for symptomatic patients, for tumors showing an aggressive pattern (i.e., changes in size on imaging or high proliferation activity and atypical epithelioid pattern on liver biopsy), for large (> 5 cm) biopsy-proven HAML, and if doubts remain on imaging or histology. Conservative management may be justified in other conditions, since most cases follow a benign clinical course. In summary, the correct diagnosis of HAML is challenging on imaging and relies mainly on pathological findings.

Hepatic angiomyolipoma: A case report and literature review

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HAML is a rare mesenchymal liver tumour which belongs to the family of perivascular epithelioid cell tumours.

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HAML is typically composed of blood vessels, smooth muscle, and adipose cells.

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HAML is characteristically positive for HMB-45.

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In patients with symptoms, uncertain diagnosis, or tumour growth, surgical resection should be performed.

Introduction

Hepatic angiomyolipoma (HAML) is a rare mesenchymal liver tumour which belongs to the family of perivascular epithelioid cell tumours (PEComas). It is typically composed of blood vessels, smooth muscle, and adipose cells, and shows strong immunoreactivity for HMB-45.

Presentation of the case

A 57-year-old woman was referred to our hospital with an unclear liver lesion. A fine needle biopsy revealed a suspicion of hepatic angiomyolipoma with extramedullary haematopoiesis. Preoperative imaging revealed a tumour 17 cm in diameter in the left liver lobe segments II and III. A lobectomy of the left lobe segments II and III was performed. The pathological diagnosis of hepatic angiomyolipoma was obtained.

Discussion

Variations in the predominance of the tissue components in HAML impedes diagnosis based on imaging alone. The most promising evidence of HAML is the histological identification of lipomatous, myomatous, and angiomatous tissue combined with immunohistochemical positivity for HMB-45. Although the tumour is considered benign, some cases have been described with malignant behaviour. Surgical resection should be considered in case of symptoms, inconclusive biopsy, or growth in follow-up. Other surgical indications may include aggressive patterns such as vascular invasion, p53 immunoreactivity, or rapidly proliferating tumour cells.

Conclusion

HAML is a rare liver tumour. In patients with symptoms, uncertain diagnosis, or tumour growth, surgical resection should be performed according to oncological criteria.

[Angiomyolipoma of the liver-a case report and review of the literature]

We report the case of a 70-year-old female patient with an unclear liver mass after clinical and radiological evaluation. In histopathological evaluation, we diagnosed a hepatic angiomyolipoma, which is a rare entity and belongs to the perivascular epithelioid group of tumours (PEComa). In this report, we illustrate the typical histomorphology, immunohistochemical profile and molecular changes based on the case presentation and discuss and review the current literature on hepatic angiomyolipomas. In addition, typical differential diagnostic problems are highlighted.

A huge hepatic angiomyolipoma with growth during 5 years of follow-up

A 45-year-old woman was referred to our hospital with a huge liver tumor that had been diagnosed as a hepatic angiomyolipoma (HAML) 5 years previously. At the time of referral, it had enlarged from 12 to 20 cm within the previous 5 years and become symptomatic. Enhanced computed tomography revealed a very large, well-defined, low-density mass occupying the entire right lobe of the liver. The patient underwent right hemi-hepatectomy. The resected specimen weighed 1620 g and measured 20 × 14 × 8 cm. The pathological diagnosis was confirmed as benign HAML. The estimated growth rate of this tumor was 44% per year with a doubling time of 826 days. Although the majority of HAMLs are stable lesions, resection should perhaps be considered when the tumor is known to be growing and exceeds 6 cm in diameter, even if it has been diagnosed as benign.

Hepatic angiomyolipoma: an international multicenter analysis on diagnosis, management and outcome

BACKGROUND

Hepatic angiomyolipoma (HAML) may easily be misdiagnosed as a malignancy. The study aim was to assess diagnostic dilemmas, clinical management and outcome of this rare tumor.

METHODS

This retrospective international multicenter study included all patients with pathologically proven HAML diagnosed between 1997 and 2017. Data on patient characteristics, diagnostic work-up, management and follow-up were analyzed.

RESULTS

Thirty-eight patients were included, 32 female. Median age was 56yrs (i.q.r. 43-64) and median HAML-diameter was 57.5 mm (i.q.r. 38.5-95.3). Thirty patients had undergone CT and 27/38 MRI of the liver, diagnostic biopsy was performed in 19/38. Initial diagnosis was incorrect in 15/38 patients, of which 13 were thought to have malignancy. In 84% biopsy resulted in a correct preoperative diagnosis. Twenty-nine patients were managed with surgical resection, 4/38 with surveillance and 3/38 with liver transplantation. Recurrence after resection occurred in two cases. No HAML related deaths or progression to malignancy were documented.

CONCLUSION

HAML diagnosis proved problematic even in hepatobiliary expertise centers. Biopsy is indicated and may provide valuable additional information when HAML diagnosis is considered on cross-sectional imaging, especially when surgical resection imposes a risk of complications. Conservative management with regular imaging follow-up might be justified when biopsy confirms (classic type) HAML.

Identification of a specific ultrasonographic finding for differentiating hepatic angiomyolipoma from hepatocellular carcinoma

OBJECTIVE

To identify specific ultrasonographic features that differentiate hepatic angiomyolipoma (HAML) from hepatocellular carcinoma (HCC).

METHODS

Twelve patients with HAML and 73 patients with HCC, whose diagnosis were pathologically confirmed at a single center in Japan between 2006 and 2016, were included in this study. The HAML and HCC cases were histologically evaluated and their histological growth patterns were compared. Using ultrasonographic data, we evaluated the imaging features representing the distinct histological differences. Ultrasonographic findings, reviewed by two examiners, were compared via interobserver variability analysis. This retrospective study was approved by the institutional ethics committee at our institute (No. 2017-1004).

RESULTS

The enrolled patients were carefully divided into two case sets: discovery case set (6 HAML patients and 37 HCC patients) and validation case set (6 HAML patients and 36 HCC patients). In the discovery case set, half of the HAML cases had intratumoral regions showing a reticular growth pattern. None of the HCC cases appeared as a region with the reticular growth pattern. The regions with the reticular growth pattern present as an intratumoral hyper echoic foci on ultrasound images. The presence of the intratumoral hyper echoic foci was significantly associated with HAML (P < .01). In the validation case set, the intratumoral hyper echoic foci predicted HAML at a specificity of 100% and a sensitivity of 50%.

CONCLUSIONS

Intratumoral hyper echoic foci, representing reticular growth pattern, can be a promising ultrasonographic finding to help differentiate HAML from HCC.

Imaging hepatic angiomyolipomas: key features and avoiding errors

Hepatic angiomyolipomas (HAMLs) are rare mesenchymal neoplasms, which have highly variable imaging appearances, often leading to misdiagnosis. They belong to the family of perivascular epithelioid cell neoplasms (PEComas). HAMLs have a wide spectrum of imaging appearances due to variable amounts of smooth muscle cells, adipose tissue, and blood vessels in their makeup. Although typically sporadic, they are also associated with tuberous sclerosis. Sporadic lesions tend to be solitary whilst patients with tuberous sclerosis often have multiple HAMLs invariably accompanied by renal AMLs. Having been originally considered benign hamartomas, increasing reports of complications, including malignant behaviour, has also resulted in uncertainty in regard to their optimal management. Typically described imaging characteristics are of a hypervascular fat-containing lesion with prominent intratumoural vessels and an early draining vein; however HAMLs commonly demonstrate a paucity of fat or wash-out on contrast-enhanced imaging, and not all HAML lesions are hypervascular. HAMLs can therefore easily be misdiagnosed as other hepatic lesions, in particular hepatocellular carcinoma. This review describes the imaging characteristics of HAMLs, illustrating the wide variety of potential appearances across ultrasound, contrast-enhanced ultrasound, computed tomography, and magnetic resonance imaging, and highlights the challenges and potential errors that can be made. This review will aid radiologists in avoiding potentially major pitfalls when faced with this rare but important liver pathology.

Giant hepatic angiomyolipoma: a case report

Hepatic angiomyolipoma (AML) is a rare mesenchymal tumour with an undetermined malignant potential. Clinical symptoms are non-specific. The radiological hallmarks are high vascularization of lesion and presence of macroscopic fat. The proportion of fatty tissue varies significantly and discrepancies between pre-operative imaging and histological findings are observed in more than 50% of cases. Visualization of the draining vein may aid in differentiation between AML and hepatocellular carcinoma with abundant fatty component. Biopsy is indicated in ambiguous cases. Presence of clinical symptoms warrants surgical treatment. We present a clinical case of giant hepatic AML, discuss its typical features and treatment options.

Malignant potential of epithelioid angiomyolipomas of the liver: A case report and comprehensive review of the literature

Hepatic epithelioid angiomyolipoma (HEAML) is a rare mesenchymal tumor that has been reported to have malignant potential. We herein describe a rare case of atypical HEAML. A 43-year-old Caucasian male patient visited his general practitioner due to a productive cough persisting for >2 months. During evaluation with several imaging tests, a chest computed tomography (CT) incidentally revealed a well-demarcated lesion in the caudate lobe of the liver, sized 7 cm. An abdominal magnetic resonance imaging examination confirmed the findings of the CT. The possibility of hepatocellular carcinoma at that time could not be excluded. Due to inconclusive cross-sectional imaging, the patient underwent left hepatectomy with additional resection of segment I. The patient's postoperative course was uneventful. A diagnosis of 'atypical' HEAML was established in the present case. The majority of HEAMLs are considered to be benign, although there are several reported cases exhibiting malignant behavior, such as tumor growth, presence of atypical cells, recurrence after surgical resection, metastasis and invasive growth into the liver parenchyma and alongside the vessels. From 2000 onwards, 19 cases of malignant hepatic AML have been reported. Malignant transformation is considered to occur mostly in the epithelioid subtype. To that end, when epithelioid or atypical characteristics are identified on preoperative biopsy, resection is indicated due to the high probability of malignancy.

Management of hepatic angiomyolipoma: A systematic review

Hepatic Angiomyolipoma (HAML) is a rare mesenchymal liver tumour assumed to be predominantly benign, although incidental cases with malignant behaviour such as invasive growth, recurrence after resection and metastases have been reported. The aim of this systematic review was to assess the biological behaviour, estimate the risk of HAML related mortality and recommend on a justifiable management strategy. We performed a systematic literature search in Embase, Medline, Web-of-Science, Scopus, Pubmed Publisher, Cochrane and Google Scholar. We included all articles published from inception until March 2016 which reported on follow-up of various treatment strategies. We included 18 articles reporting on 292 patients. Male:female ratio was estimated at 1:3 with gender not reported in 31 cases. Of 292 patients 247 were treated with surgery, including one liver transplant, seven with chemotherapy or Sirolimus, three with embolization, and 35 conservatively. Recurrence after resection was described in 6/247 (2.4%) with pathologically proven HAML resulting in metastases and death in 2/247 (mortality rate 0.8%). Progression was described in 6/35 patients treated conservatively (21.4%). Two of 12 patients with malignant behaviour of HAML had an epithelioid-type HAML, of the remaining 10 histological subtype was undefined. With a risk estimate of 0.8% in surgically treated patients HAML related mortality is very low. Biopsy is indicated when imaging is inconclusive. In case of certain HAML diagnosis on imaging conservative management with annual imaging is justified. Resection should be considered in case of symptoms, inconclusive biopsy or growth in follow-up.

Uncommon liver tumors: Case report and literature review

BACKGROUND

Beside hepatocellular carcinoma, metastasis, and cholangiocarcinoma, the imaging findings of other relatively uncommon hepatic lesions are less discussed in the literature. Imaging diagnosis of these lesions is a daily challenge. In this article, we review the imaging characteristics of these neoplasms.

METHODS

From January 2003 to December 2014, 4746 patients underwent liver biopsy or hepatic surgical resection in our hospital. We reviewed the pathological database retrospectively. Imaging of these lesions was reviewed.

RESULTS

Imaging findings of uncommon hepatic lesions vary. We discuss the typical imaging characteristics with literature review. Clinical and pathological correlations are also described. Primary hepatic lymphoma consists only of 1% of the extranodal non-Hodgkin lymphoma, and is defined as the one involving only the liver and perihepatic lymph nodes within 6 months after diagnosis. Combined hepatocellular and cholangiocarcinoma (cHCC-CC) shares some overlapping imaging characteristics with both HCC and cholangiocarcinoma because of being an admixture of them. Angiosarcoma is the most common hepatic mesenchymal tumor and is hypervascular in nature. Inflammatory pseudotumor is often heterogeneous on ultrasonography and with enhanced septations and rims in the portovenous phase after contrast medium. Angiomyolipoma (AML) typically presents with macroscopic fat components with low signal on fat-saturated magnetic resonance imaging (MRI) and presence of drainage vessels. Intraductal papillary neoplasm of the bile duct (IPNB) is thought of as a counterpart to the pancreatic intraductal papillary mucinous neoplasm. Most of the IPNBs secrete mucin and cause disproportional dilatation of the bile ducts. Mucinous cystic neoplasm (MCN) contains proteinaceous and colloidal components without ductal communication and characterizes with hyperintensity on T1-weighted imaging. Other extremely rare lesions, including epithelioid hemangioendothelioma and inflammatory pseudotumor-like follicular dendritic cell sarcoma, are also discussed. Hepatoblastoma and mesenchymal hamartoma, mostly in children, are also briefly reviewed as well.

CONCLUSION

It is important for radiologists to be familiar with the typical imaging features of the uncommon hepatic neoplasms. If imaging findings are not typical or diagnostic, further biopsy is required.

Malignant hepatic epithelioid angiomyolipoma with recurrence in the lung 7 years after hepatectomy: a case report and literature review

Angiomyolipoma (AML) arising in the liver is rare and usually benign, but it occasionally has malignant potential. A 58-year-old man with a liver tumor identified by a previous doctor with features suggestive of hepatocellular carcinoma on computed tomography (CT) underwent anterior segmentectomy of the liver in 2006. Microscopically, the tumor was composed of exclusively epithelioid cells that were scatteredly positive for human melanoma black 45 on immunohistochemistry. Accordingly, primary hepatic epithelioid AML (eAML) was diagnosed. The patient was subsequently referred to our hospital for follow-up after hepatectomy. He had event-free survival for nearly 7 years. In 2013, two well-defined round nodules were detected in the right lung field by chest CT, and partial pneumonectomy was performed for diagnosis and treatment. Histological examination of the resected lung tissue showed that it was morphologically and immunohistochemically identical to his primary hepatic eAML, leading to the diagnosis of pulmonary metastasis. This paper demonstrates a rare case of malignant hepatic eAML with late recurrence in the lung after hepatectomy.

Differentiation of lipid poor angiomyolipoma from hepatocellular carcinoma on gadoxetic acid-enhanced liver MR imaging

PURPOSE

To investigate magnetic resonance (MR) findings of angiomyolipoma (AML) on gadoxetic acid-enhanced MR imaging, and to identify features that differentiate AML from hepatocellular carcinoma (HCC) in patients with a low risk of HCC development.

METHODS

This retrospective study was institutional review board approved, and the requirement for informed consent was waived. Twelve patients with hepatic AML who underwent gadoxetic acid-enhanced MRI with no risk factors for HCC development were recruited. Twenty-seven patients with HCC under the same inclusion criteria were recruited as control. Two radiologists analyzed the images in consensus for morphologic features, enhancement patterns, and hepatobiliary phase (HBP) findings. All results were analyzed using the Mann-Whitney test, two-tailed Fisher exact test, and chi-square test.

RESULTS

Patients with AML were younger than those with HCC (48.8 ± 15 years for AML vs. 62.7 ± 14.2 years for HCC, p = 0.008) with female predominance, while most HCC patients were male (75% (9/12) vs. 15% (4/27), p < 0.001). The most prevalent enhancement pattern was arterial enhancement followed by hypointensity at portal or transitional phases for both AMLs (58% (7/12)) and HCCs (74% (20/27)) (p = 0.455). However, during the HBP, AMLs frequently showed more homogeneous hypointensity than HCCs (83% (10/12) vs. 41% (11/27), p = 0.018). When compared with the signal intensity of the spleen, the mean relative signal intensity of the AML was 91.2 ± 15.4%, while in HCCs, it was 128.7 ± 40% (p < 0.001).

CONCLUSIONS

Although AMLs showed similar enhancement patterns to HCCs during the dynamic phases of gadoxetic acid-enhanced MRI, using characteristic MR features of AML during the HBP and demographic differences, one can better differentiate AML from HCC.

Granulomatous reaction in hepatic inflammatory angiomyolipoma after chemoembolization and spontaneous rupture

A 77-year-old Japanese woman was transported to a nearby hospital due to sudden abdominal pain and transient loss of consciousness. Abdominal computed tomography (CT) suggested hemoperitoneum and hepatic nodule. She was conservatively treated. Contrast-enhanced CT two months later revealed an increased mass size, and the enhancement pattern suggested the possibility of hepatocellular carcinoma (HCC). Under a clinical diagnosis of HCC, transcatheter arterial chemoembolization (TACE) was performed. A subsequent imaging study revealed that most of the lipiodol used for the embolization was washed out. Therefore, surgical resection was performed. Histologically, the nodule contained numerous inflammatory cells including small lymphocytes, plasma cells and macrophages. Notably, epithelioid granulomatous features with multinucleated giant cells were observed in both the nodule and background liver. Some of the multinucleated giant cells contained oil lipid. Among the infiltrating inflammatory cells, spindle-shaped, histiocytoid or myoid tumor cells with eosinophilic cytoplasm were found. The tumor cells were positive for Melan A and HMB45. The nodule contained many IgG4-positive plasma cells; these were counted and found to number 72.6 cells/HPF (range: 61-80). The calculated IgG4:IgG ratio was 33.2%. The nodule was finally diagnosed as previously ruptured inflammatory angiomyolipoma modified by granulomatous reaction after TACE.

Hepatocellular carcinoma with concomitant hepatic angiomyolipoma and cavernous hemangioma in one patient

The risk of developing hepatocellular carcinoma (HCC) is strongly associated with hepatitis B virus infection. Hepatic angiomyolipoma (AML), a rare benign tumor, is composed of a heterogeneous mixture of adipose cells, smooth muscle cells and blood vessels. Here, we report the case of a 44-year-old man who developed HCC with a concomitant hepatic AML and a cavernous hemangioma, in the absence of cirrhosis. To our knowledge, based on an extensive literature search using the www.pubmed.gov website, this is the first report of an HCC case with both concomitant AML and cavernous hemangioma at the same position in the liver. The presence of the hepatitis B surface antigen was detected, but the liver function was normal. Clinical and pathological data were collected before and during the treatment. Hepatic AML was diagnosed based on the typical histological characteristics and immunohistochemical staining, which revealed, a positive staining with a melanocytic cell-specific monoclonal antibody. There was no evidence of tuberous sclerosis complex in this patient. Although the HCC was poor- to moderately-differentiated, the characteristics of the AML and the cavernous hemangioma in this patient did not match any criteria for malignancy. Hepatectomy followed by transarterial chemoembolization treatment were effective therapeutic methods for the adjacent lesions in this patient. This case is an interesting coincidence.

Hepatic angiomyolipomas: ultrasonic characteristics of 25 patients from a single center

Twenty-five pathologically proven hepatic angiomyolipomas (AMLs) were included in the study. Ultrasonic features of hepatic AMLs were reviewed. Three types of echogenicity were observed on ultrasound examination: (i) strong hyper-echogenicity, (ii) moderate hyper-echogenicity and (iii) hypo-echogenicity. Vascular signals within tumors could be detected in 22 (88.00%) tumors as multiple punctiform, filiform or dendriform signals by color Doppler flow imaging. Based on the enhancement patterns in the arterial, portal and late phases, the features of hepatic AMLs on contrast-enhanced ultrasound were divided into four subtypes: (i) "fast in slow out" (68.00%, n = 17); (ii) "fast in same out" (16%, n = 4); (iii) "fast in fast out" (12.00%, n = 3); and (iv) "fast in uneven out" (4.00%, n = 1). Contrast-enhanced ultrasound diagnosed 22 (88.00%) tumors as benign tumors and 13 (52.00%) as hepatic AMLs. Four cases were misdiagnosed as hepatic hemangioma, five cases as focal nodular hyperplasia (total = 36.00%). The rate of correct diagnosis of hepatic AMLs increased significantly from 24.00% for ultrasound alone to 52.00% for contrast-enhanced ultrasound. Therefore, information obtained from ultrasound, color Doppler flow imaging and contrast-enhanced ultrasound should be combined to improve diagnosis.

Hepatic angiomyolipoma mimicking hepatocellular carcinoma: magnetic resonance imaging and clinical pathological characteristics in 9 cases

Hepatic angiomyolipoma (HAML) is a rare mesenchymal tumor of the liver with marked histological diversity. The present study was to review the magnetic resonance imaging (MRI) and clinical pathological features of HAML resembling hepatocellular carcinoma (HCC). Nine patients who underwent surgical resection and had pathological diagnosis of HAML were retrospectively analyzed. All of 9 patients (5 males and 4 females) had a solitary hepatic mass with a median size of 4 cm (from 1.4 cm to 15.3 cm). Seven cases were identified as incidental liver tumors during health screening and 2 patients were diagnosed for hepatic mass when visited hospitals with unspecific abdominal discomfort. Before resection, 6 cases were diagnosed as HCC on MRI. MRI on chemical shift imagings showed a large amount of lipids in 5 cases. The enhancement pattern of MRI was classified into 2 types: in 2 cases, lesions with small or no vessels that demonstrated prolonged enhancement (1 mixed subtype and 1 myomatous subtype) and in 7 cases, lesions with abundant central vessels that show rapid washout (3 mixed subtypes and 4 myomatous subtypes) in the portal venous/delayed phase. All patients underwent resection of hepatic tumor and no recurrence was observed during follow-up (range: 2-24 months) of median 10 months. By immunohistochemistry, the tumor cells demonstrated positive immunostaining for human melanoma black-45, smooth muscle actin, and CD34. In conclusion, all of 9 patients with HAML presented with none or nonspecific clinical manifestations. The diagnosis of HAML relies on disease and immunohistochemistry, but not MRI due to its resemblance to HCC.

Diagnosis and treatment of hepatic angioleiomyolipoma: A case report and literature review

AIM: To investigate the clinical features, imaging manifestations, pathological characteristics, differential diagnosis, treatment and prognosis of hepatic angiomyolipoma (HAML).

METHODS: A case of HAML diagnosed at our hospital is reported. A review of the literature was performed to retrospectively analyze 540 cases reported in China between 1987 and 2014.

RESULTS: HAML was more frequently found in females (2.7:1). Most of the patients (66.7%) presented no significant symptoms, and tumor marks were negative in all the patients. CT performed better for preoperative diagnosis than MRI (CT vs MRI: χ² = 11.321, P = 0.001) and ultrasound. Immunohistochemical analyses revealed that the positive expression rates of human melanoma black-45 antigen (HMB-45), smooth muscle actin (SMA), Vimentin, CD34 and CD117 in HAML were 97.8% (357/365), 93.7% (207/221), 62.5% (30/48), 40.5% (51/126) and 39.0% (48/123), respectively. The expression of HMB-45 was considered to have great significance in confirming the diagnosis. Of all the patients, 521 (96.3%) underwent surgical intervention, and recurrence or metastasis was found in only 3 patients during follow-up.

CONCLUSION: HAML lacks specific symptoms or signs, has diverse imaging manifestations, and can be easily misdiagnosed. Pathological and immunohistochemical analyses are essential for diagnosis, and surgical treatment has a good prognosis.

Immunohistochemical character of hepatic angiomyolipoma: for its management

Hepatic angiomyolipoma (AML) is notoriously difficult to diagnose without an invasive surgery even with the recent development of the various imaging modalities. Additionally, recent reports showed its malignant behavior after the surgery; it is important to diagnose the character of each tumor including the possible malignant potential and determine the postoperative management for each case. For this purpose, we have reviewed reports and focused on the immunohistochemical staining with p53 and ki67 of the tumors showing the representative case of 60-year-old female. The imaging study of her tumor showed the character similar to the hepatocellular carcinoma, and she underwent the hepatectomy. The resected tumor stained positive for HMB-45 that is a marker of the AML, and 30–50% of the tumor cells were positively stained with Ki67 that is a mitotic marker. Also, the atypical epithelioid cells displayed p53 immunoreactivity. These results suggest the malignant potential of our tumor based on the previous reports; therefore the careful followup for this case is necessary for a long period whether it shows metastasis, sizing up, and so forth.

Hepatic angiomyolipoma: clinical, imaging and pathological features in 178 cases

The aim of the study was to review the main clinical, imaging and pathological features of hepatic angiomyolipoma (HAML). We retrospectively analyzed the imaging, pathological and clinical features of 178 patients who underwent surgical resection for HAML. Forty-three males and 135 females with a median age of 43.5 years (range: 17-76 years) were enrolled in the study. Routine blood tests, including those for α-fetoprotein, carcinoembryonic antigen, and carbohydrate antigen determinant, were normal. Liver function was classified as Child-Pugh A for all patients. Twenty-one patients were positive for hepatitis B surface antigen (HBsAg), while two had liver cirrhosis. Seventy-five lesions were located in the right hepatic lobe, 42 in the left hepatic lobe, 12 in the hepatic caudal lobe, and 49 in both left and right lobe. All patients underwent examination by ultrasound sonography (US), and additional examinations by computed tomography (CT) and magnetic resonance (MR) were carried out for 115 and 81 patients, respectively. Various diseases including HAML, liver cancer, liver hemangioma, hepatic lipoma, hepatic hamartoma, focal nodular hyperplasia and liver adenoma were diagnosed before operation. CT and MRI are more conclusive than US (US vs CT: χ(2) = 17.72, P = 0.00; US vs MRI: χ(2) = 12.14, P = 0.00), but for the sensitivity of these three imaging modalities, MRI performs the best (US vs MRI: χ(2) = 5.938, P = 0.015; CT vs MRI: χ(2) = 2.544, P = 0.111). All the patients underwent liver resection (96 right hepatic lobectomy, 41 left hepatic lobectomy and nine caudal lobe hepatic lobectomy). Several sampled tissues were positive for HBsAg (21/168, 12.5 %), β-catenin (4/41, 9.8 %), CD-34 (119/165, 72.1 %), HMB-45 (162/169, 92.9 %), SMA (145/158, 91.8 %) and vimentin (20/27, 74.1 %). The diagnosis of HAML remains difficult and mainly relies on pathological findings. For the imaging modalities, we recommend MRI examination because of its better definition and sensitivity. Although HMB-45 is considered the main histopathological biomarker for HAML, SMA may be also helpful in the diagnostic process (HMB-45 vs SMA: χ(2) = 2.37, P = 0.123). When the diagnosis of HAML is suspicious or hypothesized, surgical resection remains the recommended strategy due to the difficulty in diagnosis preoperatively and the potentially invasive growth of the lesion.

Hepatic angiomyolipoma: diagnostic findings and management

Angiomyolipoma (AML) is a benign mesenchymal tumor that is frequently found in the kidney and, rarely, in the liver. The natural history of hepatic AML has not been clarified, and, because of the similar patterns in imaging studies, such as ultrasonography, computed tomography, and magnetic resonance imaging, some of these tumors have been overdiagnosed as hepatocellular carcinoma in the past. With an increase in the number of case reports showing detailed imaging studies and immunohistochemical staining of the tumor with human melanoma black-45, the diagnostic accuracy is also increasing. In this paper, we focused on the role of noninvasive imaging studies and histological diagnosis showing distinctive characteristics of this tumor. In addition, because several reports have described tumor progression in terms of size, recurrence after surgical resection, metastasis to other organs, and portal thrombosis, we summarized these cases for the management and discussed the indications for the surgical treatment of this tumor.

Preoperative radiological characterization of hepatic angiomyolipoma using magnetic resonance imaging and contrast-enhanced ultrasonography: a case report

Introduction

A hepatic angiomyolipoma is a rare benign tumor of the liver composed of a mixture of smooth muscle cells, blood vessels and a variable amount of adipose tissue. Differentiating them from malignant liver tumors can often be very difficult.

Case presentation

We report the case of a 43-year-old Caucasian man presenting with a large liver mass in the right lobe. The results of magnetic resonance imaging and contrast-enhanced ultrasonography were consistent with a well-demarcated adipose tissue- containing tumor, showing prolonged hyperperfusion in comparison with the surrounding liver tissue. Surgery was performed and the diagnosis of hepatic angiomyolipoma was made with histopathology.

Conclusion

Preoperative radiological characterization using magnetic resonance imaging and contrast-enhanced ultrasonography may improve diagnostic accuracy of hepatic angiomyolipoma. Identification of smooth muscle cells, blood vessels and adipose tissue with a positive immunohistochemical reaction for HMB-45 is the final evidence for an angiomyolipoma.