Background: 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.
Methods: 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.
Results: 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.
Conclusions: 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.