Cutaneous PEComa does not harbour TFE3 gene fusions: immunohistochemical and molecular study of 17 cases. Issue 1 (24th May 2013)

• Record Type: Journal Article
• Authors: Llamas‐Velasco, Mar; Mentzel, Thomas; Requena, Luis; Palmedo, Gabriele; Kasten, Robert; Kutzner, Heinz
• Is Part Of: Histopathology. Volume 63:Issue 1(2013)
• Page Start: 122
• Page End: 129
• Publication Date: 2013-05-24
• Subjects: Histology, Pathological -- Periodicals; 611.018
• DOI: 10.1111/his.12145
• Languages: English
• ISSNs: 0309-0167

Abstract

<abstract abstract-type="main" id="his12145-abs-0001"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="his12145-sec-0001" sec-type="section"> <title>Aims</title> <p>The family of perivascular epithelioid cell tumours (PEComas) comprises a related group of mesenchymal tumours of uncertain origin that show both smooth muscle and melanocytic differentiation markers. TFE3 nuclear immunoreactivity may be viewed as a supporting marker, as it has been found in a subset of visceral PEComas. We immunohistochemically analysed 17 cases of primary cutaneous PEComas for TFE3, and five of them also for SOX‐10, and also analysed them by FISH for <italic>TFE3</italic> rearrangement.</p> </sec> <sec id="his12145-sec-0002" sec-type="section"> <title>Methods and results</title> <p>PEComas presented as skin‐coloured tumours, in 12 women and five men, with a median age of 49.5 years. Tumours showed either a mixed clear cell–epithelioid cell pattern or a monomorphous clear cell pattern. None of the primary cutaneous PEComas showed detectable TFE3 or SOX‐10 positivity. FISH assay for <italic>TFE3</italic> rearrangement yielded negative results in all of the tested tumours.</p> </sec> <sec id="his12145-sec-0003" sec-type="section"> <title>Conclusions</title> <p>Cutaneous PEComas are mostly composed of clear cells, and, unlike a subset of visceral and deep‐seated PEComas, cutaneous PEComas consistently lack TFE3 expression. Owing to the lack of SOX‐10 expression, a neural crest origin could not be shown.</p> </sec> </abstract>