Introduction 1 2 3 4 7 8 10 6 10 14 14 15 The purpose of this study is to retrospectively review the clinical, imaging, and pathological features of patients with hepatic AML treated at our hospital and to summarize our experience in the diagnosis and treatment of this disease. We also review the literature to highlight the important questions concerning hepatic AML: (1) Is hepatic AML a pure benign tumor? (2) What is the natural course of this tumor? Does the tumor size enlarge frequently during observation? (3) What difficulties exist in preoperative diagnosis with imaging studies and fine needle aspiration biopsy (FNAB)? (4) Is it proper for a hepatitis-carrier patient with hepatic AML to be treated with conservative management? (5) What are the criteria for patients with hepatic AML to be treated with surgical resection or conservative management? Materials and Methods The clinical, imaging, and pathological features of 10 patients with hepatic AML treated at the authors’ institute were retrospectively reviewed. The follow-up information was obtained in each case. All tumor tissue was paraffin-embedded for routine hematoxylin and eosin (H&E) staining. Immunohistochemical assays were performed using a three-step indirect peroxidase complex technique with the following antibodies: HMB-45 (DAKO, dilution 1:40), actin (DAKO, dilution 1:50), S-100 (DAKO, dilution 1:800), cytokeratin (Biogenix, dilution 1:80), vimentin (DAKO, dilution 1:50), and c-kit (MBL, dilution 1:200). Results Patients and Clinical Data 1 2 Table 1 Clinical Presentation of Hepatic Angiomyolipoma Clinical Feature No. of Patients Age 34–64 years (median 44 years) Gender (female: male) 9:1 Symptoms  No symptom 6  Abdominal pain 2  Abdominal fullness 2  Palpable mass 1  Body weight loss 2  Malaise 1  Fever 2 Tumor location  Right lobe 5  Left lobe 4  Caudate 1 Tumor size (cm)  <5 3  5–10 1  >10 6 Preoperative diagnosis Angiomyolipoma 4(40%)  Based on radiological images 2  Based on tumor biopsy 2 Hepatocellular carcinoma 3(30%) Angiosarcoma 1(10%) Hemangioma 1(10%) Metastasis 1(10%) Associated liver disease HBV carrier 2 Table 2 Clinical Profile of Patients with Hepatic Angiomyolipoma Case Sex/Age Tumor Size (cm)/lobe Symtoms/Signs Incidental Finding Treatment Outcome/F/U Months 1 F/34 18/R Nil H/C Atypical hepatectomy Well/39 mon 2 F/34 10/R Epigastralgia  Right lobectomy Well/59 mon 3 F/37 13/L Palpable mass, abdominal fullness, BW loss, fever  Extended left lobectomy Dead/14 mon recurrent, liver and lung mets 4 F/40 20/R Epigastralgia  Right lobectomy Well/109 mon 5 F/42 7/R Nil H/C FNAB and F/U Lost F/U/6mon 6 F/46 11/L Abdominal fullness, malaise, BW loss, fever  Left lateral segmentectomy Well/40 mon 7 F/49 15/R Nil Exam of appendicitis S56 segmentectomy Well/37 mon 8 F/51 3/C Nil H/C Caudate lobectomy Well/40 mon 9 F/53 2.5/L Nil F/U echo due to colon cancer s/p Left lateral segmentectomy Well/33 mon 10 M/64 4/L Nil H/C Left lobectomy Well/32mon H/C = health check-up, BW = body weight, F/U = follow-up, FNAB = fine needle aspiration biopsy, mon = month, mets = metastasis, s/p = postoperation Imaging Studies 1 1 Pathologic Study 1 2 Gross pathology identified all tumors as a well-circumscribed, nonencapsulated tumor masses consisting of soft to elastic tissue. The cut surface in tumors varied from yellow to dark brown. 3 Table 3 Immunohistochemical Study Case HMB-45 Actin S-100 Cytokeratin Vimentin c-kit 1 ++ − ++ − − + 2 ++ ++ + − + + 3 ++ − ++ − + − 4 ++ ++ − − + − 5 ++      6 ++ + ++ − + − 7 ++ − ++ − + − 8 ++ − − − + − 9 ++ − ++ − − − 10 ++ + + − + + ++: strongly staining, >30% positivity; +: weakly staining, 10∼30% positivity; − no staining, or <10% positivity Treatment and Follow-up 2 1 2 Figure 1 A 37-year-old woman (case 3) presented with fever and palpable abdominal mass. (a) The axial view of contrast-enhanced CT scans on portal venous phase shows a huge hepatic tumor at the left hepatic lobe with heterogeneous enhancement. Notice the engorged vessels within the tumor are vividly identified (arrow). (b) The MR coronal Tru FISP, fast imaging with steady-state precession. (TR/TE/FA = 4.3/2.1/72°) shows engorged vessels in the tumor. The right portal vein (arrow) is displaced by the tumor. (c) After 6 months of extended left lobectomy, the abdominal ultrasonography reveals a huge recurrent tumor (arrows) in the previous location of left hepatic lobe, and numerous smaller tumors in the right lobe. (d) Celiac angiography also demonstrates the recurrent huge tumor and other multiple smaller ones in the right lobe of liver. Note the early drainage vein (arrow).  Figure 2 Microscopic appearance of the hepatic angiomyolipoma in case 3. (a) The primary tumor is composed of polygonal to spindle cells arranged in solid sheets or trabecular pattern with endothelial lining. Some of the tumor cells have eosinophilic cytoplasm, and some have large fat vacuoles. Some of the nuclei are bizarre, and some have large eosinophilic nucleoli (H&E stain, original magnification ×100). (b) The tumor cells are strongly immunoreactive for HMB-45 (original magnification ×100). Recurrent tumor was noted 6 months later, and the patient received fine needle aspiration biopsy. (c) Microscopically, it shows tumor cells with clear to ample eosinophilic cytoplasm arranged in trabecular pattern (H&E stain, original magnification ×40). (d) Immunohistochemical staining shows the tumor cells are also positive for HMB-45 (original magnification ×200).  1 1 2 Discussion 8 9 10 8 10 13 16 16 Although hepatic AML seems slow-growing, the probability of tumor enlargement and hence an induced mass-compression effect is not uncommon in the long-term follow-up period. In the present series, the median age of patients was 44 years old, and 70% of patients were below 50 years. If all of these patients had received nonoperative management, the mass effect of tumor enlargement might have been presented during a long-term follow-up period, especially in younger patient groups with longer remaining years of life. Moreover, the difficulties and complications of operation at later years would increase when the tumor enlarges, especially for those patients with an original larger tumor (>5 cm). 12 14 11 12 17 4 5 17 18 6 10 15 15 10 3 19 14 20 21 Because of the small patient number, we could not get definitely conclusive management suggestions solely from the results of this retrospective study. But a combination of our experience and a review of the literature, we suggest all symptomatic patients should receive surgical resection for hepatic angiomyolipoma. Conservative management with close follow-up is suggested in patients with asymptomatic tumors and meet the following criteria: (1) tumor size smaller than 5 cm, (2) angiomyolipoma proved through fine needle aspiration biopsy, (3) patients with good compliance, and (4) not a hepatitis-virus carrier.