Lymphomatoid papulosis and anaplastic giant-cell lymphoma

Background: The association between lymphomatoid papulosis and malignant Hodgkin or non-Hodgkin lymphoma is well known but still raises the problem of nosology between these two pathologies. Is lymphomatoid papulosis a pseudolymphoma, a prelymphomatous state or a true skin lymphoma?

Methods: We observed a patient who had lymphomatoid papulosis and anaplastic large-cell lymphoma within an interval of 8 years between. This case was particularly interesting because identical immunophenotypes were observed in the atypical large-cells of the skin and the lymphomatous cells of the lymph nodes (positive for CD43, CD45, CD25, CD30, CD15, EMA).

Conclusions: This case points out that atypical large-cells of lymphomatoid papulosis express the CD15 antigen which is only expressed by atypical large-cells in half of the cases of lymphomatoid papulosis. In addition, EMA is classically expressed in primary lymph node lymphomas rather than in primary cutaneous anaplastic large cell lymphomas which could predict extracutaneous dissemination of lymphomatoid papulosis. Furthermore, the demonstration that the skin lesions and the lymph nodes responded differently to the same treatment would suggest that there are other unrecognized biological differences. Lymphomatoid papulosis appears to be a range of disorders of the lymphoproliferation of activated T-cells and could include varioliform parapsoriasis and cutaneous lymphoma.