Two case reports and literature review for hepatic epithelioid angiomyolipoma: Pitfall of misdiagnosis

Abstract

BACKGROUND Hepatic epithelioid angiomyolipoma (HEAML) is a rare liver disease and is easily misdiagnosed. Enhanced recognition of HEAML is beneficial to the differential diagnosis of rare liver diseases. CASE SUMMARY We presented two cases of HEAML in Changzheng Hospital, Naval Medical University, and then collected and analyzed all reports about HEAML recorded in PubMed, MEDLINE, China Science Periodical Database, and VIP database from January 2000 to March 2018. A total of 409 cases of HEAML in 97 reports were collected, with a ratio of men to women of 1:4.84 and an age range from 12 years to 80 years (median 44 years). Among the patients with clinical symptoms mentioned, 61.93% (205/331) were asymptomatic, 34.74% (115/331) showed upper or right upper quadrant abdomen discomfort, while a few of them showed abdominal mass, gastrointestinal symptoms, low fever, or weight loss. The misdiagnosis rate of HEAML was as high as 40.34% (165/409) due to its nonspecific imaging findings. Most of the tumors were solitary and round in morphology, with clear boundaries. Ultrasound scan indicated low echo with internal nonuniformity and rich blood supply in most cases. Computer tomography/magnetic resonance imaging enhanced scan showed varied characteristics. The ratio of fast wash-in and fast wash-out, fast wash-in and slow wash-out, and delayed enhancement was roughly 4:5:1. A definite diagnosis of HEAML depended on the pathological findings of the epithelioid cells in lesions and the expression of human melanoma black 45, smooth muscle actin, melanoma antigen, and actin by immunohistochemical staining. HEAML had a relatively low malignant rate of 3.91%. However, surgical resection was the main treatment for HEAML, due to the difficulty diagnosing before operation. CONCLUSION HEAML is a rare and easily misdiagnosed disease, and it should be diagnosed carefully, taking into account clinical course, imaging, pathological ,and immunohistochemical findings.

More than Pus – Primary Hepatic Epithelioid Angiomyolipoma Masquerading as Liver Abscess

“…Our patient was a 46-year-old man who was diagnosed with HEAML from targeted liver biopsy. His demographic fits in with the largest case series of 409 cases where the median age of presentation was 44 years old with the majority presenting as a single tumour [ 5 ]. Patients with HEAML are often clinically asymptomatic, HEAML being incidentally discovered during a routine check-up or while conducting imaging examination for other conditions.…”

“…Patients with HEAML are often clinically asymptomatic, HEAML being incidentally discovered during a routine check-up or while conducting imaging examination for other conditions. Rarely, patients present with abdominal distension and pain particularly in the setting of large tumours [ 5 ]. To our knowledge, there were no previously reported cases of a possible superimposed liver abscess as initial presentation to date.…”

“…On CT, these often show non-uniformity enhancement in the arterial phase and decreased enhancement during the portal and delayed phase. Similarly, contrast-enhanced MRI shows a low T1WI signal and an increase in T2WI and DWI signal with enhancement in the arterial phase with a subsequent decrease during the portal and delayed phase [ 5 ]. Specific unique imaging features supportive of AML include that of a central vessel sign and the presence of an early drainage vein returning into branches of the hepatic or portal vein [ 5 ].…”

“…Thus, it may commonly be mistaken for other types of hepatic tumours, with the rate of misdiagnosis being high in the absence of histology [ 2 ]. On histology, the definitive diagnosis of HEAML is achieved on the display of pathological findings of epithelioid smooth muscle cells, adipocytes and blood vessels in the lesions and immunohistological findings of melanoma-specific markers (human melanoma black 45, melan-A) and smooth muscle markers (smooth muscle actin) in the smooth muscle cells [ 5 ]. Within this group, a significant correlation with subsequent aggressive behaviour was seen for tumours larger than 5 cm with an infiltrative growth pattern, a high nuclear grade, severe pleomorphism, necrosis, and mitotic activity greater than 1 per 50 high-power field [ 1 ].…”

Hepatic epithelioid angiomyolipoma: a case report

“…The hepatic localization of these lesions is extremely rare. 6 It is a more frequent entity in women, in a 5: 1 ratio, with a higher prevalence between 30 and 65 years. 1 Asymptomatic in more than half of the cases, the diagnosis is mostly incidental.…”