[Morphologic variants and immunohistochemical features of hepatic angiomyolipoma].
OBJECTIVE
To study the clinicopathological characteristics, immunohistochemical features and differential diagnosis of hepatic angiomyolipoma (AML).


METHODS
The clinicopathological features of hepatic AML were systematically examined in 44 surgically resected tumor specimens, with additional immunohistochemistry study using 10 relevant antibodies.


RESULTS
The tumors were composed of various amounts of three components, i.e. blood vessels, smooth muscle cells and adipose cells. According to the proportions of each of these tissue components, AML was subcategorized into the classical type (n = 13), myomatous type (n = 25), lipomatous type (n = 4), and angiomatous type (n = 2). Myoid cells displayed various morphology, including epithelioid, intermediate (ovoid or short spindle), spindle, oncocytic, and pleomorphic features. Hematopoietic elements were present as minor findings in eight tumors. Immunohistochemically, the tumor cells were strongly positive for HMB45 (44/44, 100%), SMA (38/38, 100%) and CD117 (30/38, 78.9%).


CONCLUSIONS
A correct diagnosis of hepatic AML might be difficult due to its various growth patterns and cell types. HMB-45 positivity in the myoid cells is a key feature for hepatic AML. CD117 may be another useful ancillary marker for reaching a definite diagnosis.
Zhang
Shu-hui
SH
Department of Pathology, Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai 200438, China.
Cong
Wen-ming
WM
Xian
Zhi-hong
ZH
Wu
Wei-qing
WQ
Dong
Hui
H
Wu
Meng-chao
MC
D000328:Adult; D000368:Aged; D018207:Angiomyolipoma / Q000145:classification / Q000276:immunology / Q000473:pathology*; D000951:Antigens, Neoplasm / Q000032:analysis; D014408:Biomarkers, Tumor / Q000032:analysis; D003937:Diagnosis, Differential; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007150:Immunohistochemistry; D008099:Liver / Q000473:pathology*; D008113:Liver Neoplasms / Q000145:classification / Q000276:immunology / Q000473:pathology*; D008297:Male; D058950:Melanoma-Specific Antigens; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000032:analysis; D019009:Proto-Oncogene Proteins c-kit / Q000032:analysis
D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; D058950:Melanoma-Specific Antigens; D009363:Neoplasm Proteins; D019009:Proto-Oncogene Proteins c-kit