Published online May 28, 2016. doi: 10.3748/wjg.v22.i20.4908
Peer-review started: January 22, 2016
First decision: March 7, 2016
Revised: March 20, 2016
Accepted: March 30, 2016
Article in press: March 30, 2016
Published online: May 28, 2016
AIM: To improve the clinical diagnosis and recognition of hepatic epithelioid angiomyolipoma (HEAML).
METHODS: Four cases of primary HEAML were confirmed based on the pathology archive system in our hospital from January 2009 to November 2015. The general state, clinical symptoms, imaging manifestations, histological results and immunohistochemistry of these patients were retrospectively reviewed and analyzed. Studies of HEAML published in the last 15 years were collected from PubMed and MEDLINE to summarize the clinical symptoms, imaging characteristics, pathological features and management of HEAML.
RESULTS: Four cases of primary HEAML were retrieved from our archives. These included three female patients and one male patient, with a mean age of 41.8 ± 11.5 years (ranging from 31 to 56 years). The mean tumor size was 7.3 ± 5.5 cm (ranging from 3.0 to 15 cm). In the contrast-enhanced imaging, the tumor was obviously enhanced in the arterial phase, but enhanced continuously or exhibited a slow-density masse during the venous and delayed phases. Histologically, the tumors mainly consisted of epithelioid cells that comprised approximately 95% of the total neoplastic mass. Although no metastases occurred in our patients, pathological studies revealed necrosis, mitotic figures and liver invasion in two patients, which indicates aggressive behavior. Immunohistochemical staining revealed that human melanoma black 45 (HMB-45) and Melan-A were positive in 4 cases. We only identified 81 cases with primary HEAML, including our present patients, from 26 articles available from PubMed and MEDLINE. The majority of the papers were published as case reports. Only 5 (5/75, 6%) cases were associated with tuberous sclerosis complex (TSC). More than half (35/66) were discovered incidentally upon physical examination. Approximately 65% (22/34) of the patients were misdiagnosed with HCC or other tumors before surgery. Approximately 10% (8/81) of the patients with HEAML had recurrence or metastasis after surgery, which was a very high and alarming rate.
CONCLUSION: HEAML is a very rare primary hepatic tumor that is often misdiagnosed before surgery. Patients should be followed closely after surgery because of its malignant potential.
Core tip: Hepatic epithelioid angiomyolipoma (HEAML) is very rare tumor that is often misdiagnosed because of atypical symptoms and imaging manifestation. The diagnosis can be made based upon characteristic pathological and immunohistochemical criteria. Traditionally, it is thought to be a benign tumor and is therefore largely ignored. Thus, it is important to improve the recognition of HEAML. This is the first article to analyze the clinicopathological data and imaging results of HEAML comprehensively by combining our four patients with other cases reported worldwide. In fact, HEAML has malignant potential and should be followed closely after surgery.