Hepatic angiomyolipoma: two case reports of caudate-based lesions and review of the literature.
ABSTRACT Two case reports of hepatic angiomyolipoma, both originating in the caudate lobe, are reported with a review of the literature. The liver is the second most common site of angiomyolipoma, an uncommon benign tumor of mixed mesenchymal origin. It is commonly diagnosed following abdominal pain or as an asymptomatic mass discovered on abdominal ultrasound or computed tomography scan. Of 74 cases reported, the lesions ranged from 0.3 to 36 cm in diameter and are noted between the first and eighth decade, with predominant female predilection. The right lobe is the most common site, with lesions arising in the caudate lobe comprising only five cases. The natural history of the hepatic lesion is unknown. Malignant invasion or metastatic disease has not been documented. Hepatic and renal angiomyolipoma can occur concurrently (13 of 60 cases), although the majority are not biopsy proven. Multicentric hepatic disease occurs. The correlation between tuberous sclerosis and hepatic angiomyolipoma is not confirmed histologically and occurs rarely. These lesions have a characteristic radiographic appearance due to high fat content. Histologically, angiomyolipoma are characterized by an admixture of adipose tissue, blood vessels, and smooth muscle cells. These lesions cannot reliably be differentiated from a malignant lesion based on clinical history, radiologic examination, and/or pathologic interpretation. If clinical suspicion for malignancy is low, then careful observation with serial radiologic follow-up is performed. The treatment for a symptomatic or suspicious lesion is resection, if feasible. Liver transplantation may be considered for large or centrally located lesions not amenable to resection.
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ABSTRACT: Angiomyolipoma (AML) is a benign mesenchymal tumor that has been frequently reported in the kidney but rarely in the liver. Hepatic AML may be clinically, radiologically and morphologically difficult to distinguish from hepatocellular carcinoma or other hepatic lesions, even though the number of cases has been increasing recently due to improved imaging techniques. Histologically it consists of smooth muscle cells, adipose cells and abnormal blood vessels. It is commonly diagnosed following abdominal pain but may also be asymptomatic, has a predominant female predilection, highly variable size and occurs in subjects with a wide age range. The right lobe is the most common site, and multicentricity has been reported. Here we report a case of the myomatous variant of AML, accidentally discovered in a young woman with no clear features on radiographic examination, which was diagnosed by means of fine needle aspiration biopsy (FNAB) and then surgically removed. Although careful observation with serial radiological follow-up is an option in these cases, we chose the surgical approach because of the risk of rupture due to the large size of the lesion and the risk of malignant behavior or transformation. In case of the myomatous variant composed of irregular cells with epithelioid appearance, hepatocellular carcinoma with fatty changes or the possibility of other malignant tumors must be ruled out by immunohistochemistry (HMB-45), even in biopsy specimens.Tumori 90(1):139-43. · 0.86 Impact Factor