Premium
BRAF mutation in ‘sarcomas’: a possible method to detect de‐differentiated melanomas
Author(s) -
Cipriani Nicole A,
Letovanec Igor,
Hornicek Francis J,
Mullen John T,
Duan Zhenfeng,
Borger Darrell R,
Nielsen Gunnlaugur Petur
Publication year - 2014
Publication title -
histopathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.626
H-Index - 124
eISSN - 1365-2559
pISSN - 0309-0167
DOI - 10.1111/his.12305
Subject(s) - melanoma , sarcoma , undifferentiated pleomorphic sarcoma , malignancy , mutation , cancer research , pathology , medicine , immunohistochemistry , v600e , spindle cell sarcoma , biology , soft tissue sarcoma , gene , genetics
Aims BRAF is mutated in 50–60% of melanomas, but BRAF 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 BRAF mutation in sarcomas and the use of BRAF mutational status in the diagnosis of spindle cell malignancies. Methods and results BRAF 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, BRAF mutation was absent. In the sarcoma–melanoma group, three sarcomas showed BRAF mutation; all were UPS , occurred after the melanomas and did not stain for melanocytic markers. One melanoma–sarcoma pair showed identical BRAF V600E mutations. Conclusions The presence of BRAF mutation in these tumours raises the possibility that poorly differentiated spindle cell malignancies with BRAF mutation may represent melanomas, and BRAF 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.