D2-40 Expression in Epithelioid Fibrous Histiocytoma.
Jyoti P Kapil, Michael S McLemore, Victor G Prieto. George Washington University Hospital, Washington, DC; UT – MD Anderson Cancer Center, Houston, TX
Background: Epithelioid fibrous histiocytoma (EFH) is a variant of benign fibrous histiocytoma (BFH) that has a distinct histologic appearance but can be easily confused with other neoplasms, including melanocytic lesions. By immunohistochemistry (IHC), EFH is positive for factor XIIIa and CD68. D2-40, a lymphatic endothelial and dendritic cell marker, has been proposed as a very sensitive marker for standard BFH (100% of cases in a single series). However, no study has examined D2-40 expression specifically in EFH.
Design: For the present study, we searched the pathology files of our institution for cases diagnosed as epithelioid fibrous histiocytoma. From 2000-2010, there were nine cases with available slides. We performed IHC for D2-40, Factor XIIIa, CD68, CD163, and S100. Three pathologists reviewed the IHC results and quantified the percentage of epithelioid cells labeled and their intensity on a four-tier scale from 0 (negative) to 3+ (strong).
Results: D2-40 expression was seen in 8/9 cases, and in a majority of cases, greater than 40% of the epithelioid cells showed cytoplasmic and membranous labeling (See Table). Factor XIIIa expression was seen in 7/7 cases, in 5% to 60% of the epithelioid cells. CD68 expression was seen in 8/8 cases, greater than 60% of epithelioid cells in seven cases. CD163 expression was seen in 6/9 with 10% to 80% of epithelioid cells being positive. S100 was not expressed in any case.
|#||Age (years), Sex||Site||D2-40*||FXIIIa*||CD68*||CD163*||S100*|
|1||68, M||right thigh||40%, 3+||40%, 3+||60%, 2+||-||-|
|2||40, M||right arm||10%, 1+||NA||NA||10%, 1+||NA|
|3||46, M||chest||-||20%, 1+||60%, 2+||-||-|
|4||38, F||external auditory canal||60%, 2+||20%, 1+||90%, 2+||80%, 3+||NA|
|5||44, M||right shoulder||70%, 2+||60%, 1+||80%, 1+||30%, 3+||NA|
|6||20, M||arm||90%, 1+||30%, 2+||60%, 2+||30%, 3+||-|
|7||20, M||nostril||90%, 1+||5%, 1+||10%, 2+||20%, 3+||-|
|8||24, F||nostril||80%, 2+||10%, 1+||80%, 2+||60%, 3+||-|
|9||18, F||right shoulder||90%, 3+||NA||100%, 3+||-||-|