Laparoscopic hepatectomy for hepatic angiomyolipoma with preoperative diagnosis of other malignancy: a report of 2 cases

BACKGROUND: Hepatic angiomyolipoma (HAML) is a rare liver tumor, and hepatectomy is the only effective treatment. Due to the difficulty of correct diagnosis of HAML before surgery by image studies, more than 36.6% of reported HAMLs are misdiagnosed as other malignant liver tumors before surgery. As there are only few reported cases in which HAMLs were removed using laparoscopic hepatectomy, the effectiveness of laparoscopic hepatectomy for such HAMLs in which are diagnosed as other malignant liver tumor before surgery has not been reported. Case presentation Case 1: a 58-year-old female with a history of treatment for autoimmune hepatitis was preoperatively diagnosed with hepatocellular carcinoma (size: 20 mm) in segment 7 (S7) of the liver. The tumor was removed by laparoscopic partial resection and was diagnosed as a HAML through a pathological examination. The patient’s postoperative course was good, and she was recurrence-free at 37 months after the hepatectomy. Case 2: a 29-year-old female with a history of surgery for a right mature cystic teratoma was referred to our department to receive treatment for a growing 20-mm liver tumor with some calcification, which arose in S3 of the liver. A metastatic liver tumor derived from the mature cystic teratoma was suspected, and laparoscopic left lateral sectionectomy was performed. The liver tumor was diagnosed as a HAML after a pathological examination. The patient’s postoperative course was unremarkable, and more than 54 months have passed since the hepatectomy without any recurrence. CONCLUSIONS: Two cases in which HAMLs were preoperatively diagnosed as other malignant liver tumor were successfully removed by laparoscopic hepatectomy with a correct postoperative diagnosis. Laparoscopic hepatectomy for the present 2 cases of HAML seemed to be effective for providing a correct diagnosis after the curative removement of liver tumor with a smaller invasion compared to open hepatectomy, and for denying risk of dissemination of the malignant tumor by needle biopsy that had to be considered before ruling out malignant tumor.