INTRAVASCULAR (ANGIOTROPIC) LARGE-CELL LYMPHOMA - DETERMINATION OF MONOCLONALITY BY POLYMERASE CHAIN-REACTION ON PARAFFIN-EMBEDDED TISSUES

Angiotropic lymphoma is a rare, aggressive, intravascular non-Hodgkin' s lymphoma, usually of B-cell phenotype. Because lymphoma is often cli nically unsuspected, the small skin or muscle biopsies typically obtai ned for evaluation make assessment of lymphoid clonality through cell surface markers or Southern blot hybridization analysis difficult or i mpossible. The recent development of polymerase chain reaction methodo logies to detect chromosomal translocations and immunoglobulin heavy c hain gene rearrangement on paraffin-embedded tissue offers an attracti ve alternative for ascertaining the clonality of lymphoproliferative p rocesses. We report a case of B-cell angiotropic lymphoma in which a m onoclonal variable diversity joining region rearrangement of the immun oglobulin heavy chain locus was detected by polymerase chain reaction in both ante- and postmortem, formalin-fixed, paraffin-embedded skelet al muscle. The use of polymerase chain reaction in assessing clonality in angiotropic lymphoma is enhanced by the general absence of a backg round of reactive B-lymphoid cells in angiotropic lymphoma, which can obscure the monoclonal band and/or compromise sensitivity. No amplific ation product was obtained for t(14;18) involving the bcl-2 major brea kpoint region. It is interesting to note that this case exhibited rare circulating lymphoma cells and more extensive bone marrow involvement (more than 100 tumor cells/high magnification field) than has been pr eviously described.