Expression of CD44 and CD44v6 in primary cutaneous CD30 positive T-cell lymphoproliferative disorders.

Background: Expression of the lymphocyte homing receptor CD44 and its variant form, CD44v6, have been linked to unfavorable prognosis and tumor dissemination in non-Hodgkin's lymphoma. The role of CD44 and CD44v6 in primary cutaneous lymphomas may not necessarily correlate with that observed in nodal lymphomas. Our study attempts to evaluate the expression pattern of CD44 and CD44v6 in primary cutaneous CD30 positive T-cell lymphoproliferative disorders including primary cutaneous anaplastic large cell lymphoma (cALCL) and lymphomatoid papulosis (LyP) and compared the expression between these two subgroups.

Methods: Immunohistochemical staining of CD44 and CD44v6 was performed on 10 cALCL and 18 LyP cases.

Results: CD44 consistently expressed in all cases of primary cutaneous CD30 positive T-cell lymphoproliferative disorders. In contrast with previous studies, our results showed that CD44v6 expressed in 46% of all cases, including 50% cALCL and 44% LyP. There was no statistic difference in expression of CD44 or CD44v6 between cALCL and LyP subgroups.

Conclusions: These results provide a new evidence that CD44v6 is expressed in a subset cases of primary cutaneous CD30 positive T-cell lymphoproliferative disorders and suggest that other factors or molecules rather than CD44 or CD44v6 are responsible for the difference between cALCL and LyP.