1999 Volume 11 Issue 4 Pages 255-264
We performed an immunohistochemical study of hepatic angiomyolipomas (AMLs) which specifically focused on the nature of the smooth muscle-like cells (SMLCs) which are usually the most prominent component of AML. Consistent with previous reports, the SMLCs showed strong diffuse staining for HMB-45, and the more dominant epithelioid SMLCs also expressed S-100, CD68, GFAP and synaptophysin. Co-expression of these markers is often seen in neuroectodermal tumors including melanocytic tumors and nerve-sheath tumors. By contrast, the spindle-shaped SMLCs which have myoid features also expressed vimentin and α-SMA. However these immunophenotypic variation of the SMLCs was not always matched by the parallel morphologic variation. Moreover the staining intensity of the SMLCs for tuberin decreased. And the SMLCs were diffusely positive for c-fos, TGF-β, and osteonectin. The hepatic AMLs consist of mainly HMB-45-positive SMLCs which have heterogenous multipotential phenotypic expression and above all neuroectodermal differentiation that includes melanocytic and schwannian differentiation. Moreover the growth with abnormal differentiation of the SMLCs must be closely based on the regulations of some factors such as tuberin, c-fos, TGF-β, and osteonectin.
