Angioimmunoblastic T‐cell lymphoma with cutaneous involvement

Extranodal Marginal Zone Lymphoma–like Presentations of Angioimmunoblastic T-Cell Lymphoma

“…Interestingly, overexpression of c-maf has been shown in up to 75% of T-cell lymphomas 35,36 , and is linked to increased expression of VEGF, or vascular endothelial growth factor, and tumor replication 37 . Increased vascularity is a well-known feature of AITL in lymph nodes, and neoangiogenesis and increased vascularity has been documented in up to 40% of AITL with cutaneous dissemination 2,10,11,14,15,38 . Notably, FDC and endothelial cells in AITL show increased expression of FasL, while the tumor cells express Fas (CD95), highlighting the important role played by the interaction of Fas and FasL in the disease pathogenesis, and the close relationship between the environment of tumor cells and vessels 10 .…”

Lymphomes T angio-immunoblastiques

“…La présentation dermatologique est le plus souvent aspécifique, peu évocatrice du diagnostic de lymphome, et plus en faveur d'un exanthème viral ou d'une réaction d'hypersensibilité médi-camenteuse [16]. Il s'agit dans la plupart des cas d'éruptions morbilliformes ou maculopapuleuses, parfois transitoires, prédo-minant au niveau du tronc ou généralisées [16,17,[27][28][29]. D'autres types de lésions peuvent être observés : un purpura infiltré ou non, parfois nécrotique, des plaques infiltrées, des nodules, en général violacés, une urticaire ou une érythroder-mie avec desquamation secondaire [16,17,[27][28][29][30][31].…”

“…Dans certains cas, c'est un profil oligoclonal T qui peut être mis en évidence, avec la coexistence de plusieurs clones T [50,54]. Dans les lymphomes T LAI, la population clonale T est présente au niveau ganglionnaire, mais aussi au niveau médullaire [37], cutané [16,28], digestif [37], pulmonaire [37], sanguin [5,16], synovial [34] ou dans le LCR (liquide céphalorachidien) en cas d'atteinte lymphomateuse. C'est un critère diagnostique important.…”

Angioimmunoblastic T-cell lymphoma

“…Lymph node biopsy shows a tumor composed of lymphoid cells with proliferation of arborizing vessels and effacement of nodal architecture. [3,4,8,10] Immunophenotypic studies of the dermal lymphoid infiltrates are poorly informative. Lymphoid cells are positive for CD3, CD4, and CD21 with partial positivity for CD8 and CD30.…”

“…[4,8] Plasma cells, eosinophils and a dense infiltration of medium to large pleomorphic cells may be seen. [9,10] Martel et al classified this variant of T-cell lymphoma into four histologic groups as follows: (1) non-specific pattern of mild perivascular infiltrates of eosinophils and lymphocytes with no atypia in the superficial dermis associated with capillary hyperplasia; (2) sparse superficial perivascular infiltrates of atypical lymphocytes with pleomorphic and kidney-shaped nuclei associated with vascular hyperplasia; (3) dense pleomorphic infiltrate composed of atypical lymphocytes in the superficial and deep dermis, suggestive of cutaneous lymphoma; and (4) vasculitis without cellular atypia. [1,9] The histopathological features are usually non-specific and a small percentage of patients show features suggestive of a cutaneous T-cell lymphoma.…”