Lack of CD 29 (beta 1 integrin) and CD 54 (ICAM-1) adhesion molecules in intravascular lymphomatosis

Intravascular Lymphomatosis (PL) is is rare and usually aggressive form of non-Hodgkin's lymphoma characterized by the growth of neoplastic cells with in vascular lumina that usually presents with skin or central nervous syste m (CNS) involvement. The mechanism(s) for the selective intravascular growt h of this neoplasm remain(s) unexplained. We now report clinical and immuno histologic data on surgical material from 6 cases of IL; in 4 of 6 cases, a utopsies were performed. Our IL cases shared the following features: (1) B- cell lineage; (2) lack of skin involvement at presentation; (3) aggressive behavior; and (4) lack of extravascular lymphomatous masses; in addition, I case had an associated gastric low-grade MALT lymphoma. We studied by immu nohistochemistry formalin-fixed, paraffin-embedded sections with monoclonal antibodies to molecules known to be involved in lymphocyte and endothelial adhesion phenomena, that is, CD29 (beta(1) integrin subunit), CD43 (leukos ialin), CD44 (H-CAM), CD54 (ICAM-1), embryonal N-GAM (e-NCAM), and EMA (epi sialin). In all cases, the surfaces of IL aggregates reacted for CD44 but w ere consistently negative for CD29; also absent was CD54. Conversely, the i ntegrity of the endothelial cells was underscored by their even reactivity for CD29, CD44, and CD54. Given that CD29 is currently regarded as critical for lymphocyte trafficking in general and for transvascular migration in p articular, and CD54 is also involved in transvascular lymphocyte migration, we conclude that their consistent absence in IL may contribute to its intr avascular and disseminated distribution pattern, The rather frequent associ ation of IL with various conventional lymphomas is known; pet, one of our c ases appears to be the first report of IL associated with a low-grade MALT lymphoma. Copyright (C) 2000 by WE. Saunders Company.