LN2, CD10, and Ezrin Do Not Distinguish Between Atypical Fibroxanthoma and Undifferentiated Pleomorphic Sarcoma or Predict Clinical Outcome

Abstract

AFX can be treated with MMS with rare instances of recurrence. Undifferentiated pleomorphic sarcoma has a more aggressive clinical course with increased risk for recurrence and metastasis. Staining with ezrin, LN2, and CD10 did not differentiate AFX or UPS tumors.

Risk factors for local atypical fibroxanthoma recurrence and progression to pleomorphic dermal sarcoma: A meta‐analysis of individualized participant data

“…The differentiation between AFX and PDS is challenging since the tumors resemble each other both histopathologically and immunohistochemically. PDS is distinguished from AFX by features such as histological invasion of the subcutaneous tissue, vascular or perineural invasion, the presence of necrosis or local invasion/metastases 31,32 . The current consensus is that AFX does not metastasize 9,10 ; therefore, we chose to consider the cases of metastasis as a progression of the primary AFX diagnosis to a PDS.…”

“…PDS is distinguished from AFX by features such as histological invasion of the subcutaneous tissue, vascular or perineural invasion, the presence of necrosis or local invasion/metastases. 31,32 The current consensus is that AFX does not metastasize 9,10 ; therefore, we chose to consider the cases of metastasis as a progression of the primary AFX diagnosis to a PDS. Whether this means that the patients in our cohort who initially were diagnosed with AFX should have been classified as a primary PDS or that the patients had a nonradically excised primary AFX that subsequently progressed to a PDS is therefore debatable.…”

An extremely scarce incidence of primary Undifferentiated Pleomorphic Sarcoma of the Scalp of a 52-year-old female - A Case Report

“…Nevertheless, the ultimate diagnosis is defined via thorough immunohistochemical analysis [18] . Some of the IHC markers used to differentiate UPS from other STS include CD68, CD30, S100, SMA, Kinases, Desmin, Vimentin, Ki-67 proliferation index, and p53 [12] , [19] , [20] , [21] , [22] .…”

Atypical Fibroxanthoma Demonstrating HMB45+ Staining

“…It should be noted that this distinction more often proves futile than not in application to a clinical setting. 6 Immunohistochemistry is considered necessary for the diagnosis of AFX. A typical starting panel of antibodies includes S100 and/or SOX10, CD10, desmin, SMA, CK5/ CK6, p63 and/or p40, and ERG and/or CD31, while other stains that can be used for completeness and to exclude other entities in the differential diagnosis include MART-1/Melan-A, HMB45, CD68, EMA, and procollagen-1.…”