Fascin expression in CD30-positive cutaneous lymphoproliferative disorders.

CD30-positive cutaneous lymphoproliferative disorders (LPD) represent a spectrum of diseases ranging from low-grade (lymphomatoid papulosis; LyP) to high-grade (pleomorphic and anaplastic large-cell lymphoma; PTL, ALCL) with overlapping morphologic and immunophenotypic features. The common phenotypic hallmark is the expression of CD30-antigen by the tumor cells which morphologically resemble Reed-Sternberg cells. Although LyP is a non-fatal recurring disorder, it is associated with systemic lymphomas including Hodgkin's lymphoma (HL), mycosis fungoides (MF) and ALCL in 5-20% of the cases. Currently there is no marker to predict the development of systemic lymphomas in patients with LyP. Fascin, an actin bundling protein, has recently been shown to be a unique marker found in almost 100% of classical HL. Because of the association of LyP with HL, fascin expression was analyzed by immunohistochemistry in LyP (n = 45), cutaneous CD30+ ALCL (n = 17) and pleomorphic T-cell lymphoma (n = 9) (PTL) and LyP associated with systemic lymphomas (7 HL, 2 ALCL, 1 MF), with the intent to determine if fascin expression can predict disease progression. Fascin was expressed by tumor cells in 11/45 (24%) cases of LyP, 11/17 (64%) cases of ALCL, 7/9 (77%) cases of PTL and 6/10 (60%) cases of LyP associated with systemic lymphomas. Fascin expression in LyP was significantly less frequent than in ALCL (p < 0.001) and also than in LyP associated with lymphomas (p < 0.05). There was no significant difference of fascin expression within the histological subtypes of LyP. We found no evidence of ALK expression nor of Epstein-Barr virus expression in any case either by in situ hybridization or immunohistochemistry in the LyP cases associated with HL. This is the first study to demonstrate that fascin is expressed in cutaneous CD30+ LPD and that it is a candidate marker of disease progression in LyP.