Spontaneous rupture of a hepatic angiomyolipoma: Report of a case

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.

[Angiomyolipoma of the liver]

Angiomyolipoma of the liver is an extremely rare neoplasm, the number of reported cases of this disease is only about 600 worldwide. Morphological criteria for neoplasm verification present difficulties due to low occurrence and complexity of differential diagnostic search. In this regard, this observation is of interest to pathologists and physicians. A special feature of this tumor is the presence of three components: adipose, vascular and muscular with characteristic epithelioid cells. The article presents the clinical and morphological characteristics of liver angiomyolipoma in a 40-year-old woman. The diagnosis was confirmed by immunohistochemical study: a positive reaction with HMB45, Melan A, SMA, desmin, CD31, CD34; proliferative index was more than 25%.

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: 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.

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.

Selecting a suitable surgical treatment for hepatic angiomyolipoma: a retrospective analysis of 92 cases

BACKGROUND

Hepatic angiomyolipoma (HAML) is a rare and difficult-to-diagnose liver tumour. The aim of this study was to summarize experiences in the management of HAML and to recommend a practical treatment strategy.

METHODS

We retrospectively studied 92 patients who were diagnosed with HAML and analysed the clinical presentation, histopathological features and treatment of the tumours encountered at our institute from May 2009 to June 2016.

RESULTS

The patients included 67 females and 25 males who underwent at least one radiographic examination. Sixty-eight patients underwent radical hepatectomy, two patients underwent liver biopsy, and 22 patients were treated with radiofrequency ablation after liver biopsy. The tumour cells correspondingly expressed both melanoma cell markers (HMB45, MART-1) and smooth muscle cell markers. Two patients were found to have tumour recurrence (2/92, 2.2%) after radical hepatectomy, and none of the patients died.

CONCLUSION

Diagnosis of HAML depends on pathological findings. The treatment strategy for HAML should be selected according to the tumour size, liver biopsy, location and clinical symptoms of HAML. Patients should be followed closely after surgery because of the malignant potential of HAML.