Clinico-pathological correlation of hepatic angiomyolipoma: a series of 23 resection cases.

BACKGROUND: Angiomyolipomas are rare neoplasms of mesenchymal origin and are derived from perivascular epithelioid cells. They usually develop in the kidney and rarely in the liver. Due to their rarity, most hepatic angiomyolipomas have been misinterpreted as hepatocellular carcinoma (HCC) or other hypervascular liver tumours on imaging studies. We aimed to assess the clinico-pathological correlation of hepatic angiomyolipoma.

METHODS: We identified 23 patients with hepatic angiomyolipoma through an institutional database search.

RESULTS: Of 5680 cases of primary liver tumours, 23 (0.4%) had angiomyolipomas (mean age, 43.6 ± 12.4 years; 16 female patients). Hepatitis B virus infection was noted in four patients, whereas a liver mass was incidentally detected on routine health screening in 13 patients. The preoperative diagnoses, before liver biopsy, included HCC in 14, angiomyolipoma in six, focal nodular hyperplasia in two and hepatic adenoma in one patient. Eventually, the preoperative diagnoses were changed to HCC in 12 and hepatic angiomyolipoma in 11 patients. The tumour size was 5.3 ± 4.6 cm, and 22 patients had a single tumour. All tumours exhibited positive findings for human melanoma black-45 and smooth muscle actin staining. During a follow-up period of 52.2 ± 23.7 months, none of the patients exhibited tumour recurrence or mortality.

CONCLUSIONS: Hepatic angiomyolipoma is a rare form of primary liver tumour and is often misdiagnosed as other hypervascular tumours. Although angiomyolipoma is benign in nature, it also has malignant potential; hence, resection is indicated if the tumour grows or malignancy cannot be excluded. Surgical resection is a definitive curative treatment of hepatic angiomyolipoma.