Premium
Monotypic epithelioid angiomyolipoma of the liver
Author(s) -
Shigetaka Yamasaki,
Shinji Tanaka,
Hiroaki Fujii,
Toshifumi Matsumoto,
Chozaburo Okuda,
G Watanabe,
K Suda
Publication year - 2000
Publication title -
histopathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.626
H-Index - 124
eISSN - 1365-2559
pISSN - 0309-0167
DOI - 10.1046/j.1365-2559.2000.00848.x
Subject(s) - angiomyolipoma , pathology , epithelioid cell , desmin , tuberous sclerosis , biology , vimentin , hmb 45 , eosinophilic , clear cell , perivascular epithelioid cell , immunohistochemistry , anatomy , medicine , kidney , endocrinology
Aims Monotypic epithelioid angiomyolipoma is a recently recognized renal tumour, which is composed purely of epithelioid cells coexpressing markers of both smooth muscle differentiation and melanogenesis (HMB45). We report here the first case of monotypic epithelioid angiomyolipoma arising in the liver. Case details A 30‐year‐old woman without tuberous sclerosis complex (TSC) was incidentally found to have a hepatic mass by ultrasonography. Grossly, the resected tumour showed a nodule‐in‐nodule appearance, with large areas of haemorrhagic necrosis. Microscopically, the tumour was composed of pleomorphic epithelioid cells with clear, eosinophilic cytoplasm. Neither adipocytes nor abnormal vessels were recognized in the tumour. Immunohistochemically, the tumour cells were strongly positive for HMB45 and S100 protein, focally positive for desmin, vimentin and smooth muscle actin, and negative for epithelial markers (cytokeratins, EMA). Ultrastructural analysis showed numerous dense granules with some striated ones resembling melanosomes, myofilaments and pinocytic vesicles in the cytoplasm. Molecular analysis showed no allelic loss of the TSC2 region or 12 other chromosomal regions. The patient is free of disease over 1 year after the operation. Conclusion We consider that this hepatic tumour is closely related to angiomyolipoma, and a counterpart of renal monotypic epithelioid angiomyolipoma.