BRAF mutation in 'sarcomas': a possible method to detect de‐differentiated melanomas. Issue 5 (7th December 2013)

• Record Type: Journal Article
• Authors: Cipriani, Nicole A; Letovanec, Igor; Hornicek, Francis J; Mullen, John T; Duan, Zhenfeng; Borger, Darrell R; Nielsen, Gunnlaugur Petur
• Is Part Of: Histopathology. Volume 64:Issue 5(2014)
• Page Start: 639
• Page End: 646
• Publication Date: 2013-12-07
• Subjects: Histology, Pathological -- Periodicals; 611.018
• DOI: 10.1111/his.12305
• Languages: English
• ISSNs: 0309-0167

Abstract

<abstract abstract-type="main" id="his12305-abs-0001"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="his12305-sec-0001" sec-type="section"> <title>Aims</title> <p> <italic>BRAF</italic> is mutated in 50–60% of melanomas, but <italic>BRAF</italic> mutation in sarcomas has not been systematically evaluated. Some melanomas are spindled and may show no immunohistochemical evidence of melanocytic differentiation. Similarly, many sarcomas are undifferentiated, i.e. undifferentiated pleomorphic sarcomas (UPS). Diagnosing melanoma versus sarcoma in an undifferentiated spindle cell malignancy can be challenging. Our aim was to evaluate the prevalence of <italic>BRAF</italic> mutation in sarcomas and the use of <italic>BRAF</italic> mutational status in the diagnosis of spindle cell malignancies.</p> </sec> <sec id="his12305-sec-0002" sec-type="section"> <title>Methods and results</title> <p> <italic>BRAF</italic> mutational analysis was performed on tissue from 104 patients: 90 with sarcoma only (50 UPS) and 14 with sarcoma and melanoma (seven UPS). In the sarcoma‐only group, <italic>BRAF</italic> mutation was absent. In the sarcoma–melanoma group, three sarcomas showed <italic>BRAF</italic> mutation; all were UPS, occurred after the melanomas and did not stain for melanocytic markers. One melanoma–sarcoma pair showed identical <italic>BRAF</italic> V600E mutations.</p> </sec> <sec id="his12305-sec-0003" sec-type="section"> <title>Conclusions</title> <p>The presence of <italic>BRAF</italic> mutation in these tumours raises the possibility that poorly differentiated spindle cell malignancies with <italic>BRAF</italic> mutation may represent melanomas, and <italic>BRAF</italic> mutational analysis should be considered in a patient with a spindle cell malignancy and a history of melanoma, as a positive result may indicate de‐differentiated melanoma.</p> </sec> </abstract>