Anti-CD7 monoclonal antibody, clone NFN-297 [PerCP/Cy5.5®]

Loss of CD26 surface expression on the circulating malignant T-cell is the most widely accepted diagnostic marker in patients with leukemic cutaneous T-cell lymphoma (CTCL). CTCL cases with reemergence of CD7 and/or CD26 surface expression are unusual and of uncertain prognosis. We report the case of an erythrodermic leukemic mycosis fungoides patient who had achieved temporary remission after several months on multimodality immunotherapy and extracorporeal photopheresis, but who relapsed with aggressive disease phenotypically characterized by CD4+ T-cells with high CD26 expression. Polymerase chain reaction studies and high-throughput sequencing analyses from peripheral blood mononuclear cells at presentation and relapse consistently showed an identical clonal T-cell receptor suggesting evolution of her original malignant clone which lacked CD26 expression. Interestingly, quantitative expression of the sialomucin, CD164, mirrored her clinical picture, thus favoring its reliability as a novel biomarker in CTCL.

Background. Aggressive epidermotropic cutaneous T-cell lymphoma (AECL) is a rare and aggressive form of lymphoma that exhibits systemic spread within a few months that is not preceded by any indolent form. Herein, we report a case of AECL occurring on foot lesions present for six years, and initially diagnosed as Woringer-Kolopp disease, or pagetoid cutaneous T-cell lymphoma. Patients and methods. A male patient presented an ulcerated lesion of the ankle that had been present for six years. Biopsy revealed pagetoid migration of CD8+, CD2-, CD5-, CD7+, CD30- and CD56- lymphocytes with expression of cytotoxic markers and of Ki67 in over 60% of cells. The resulting diagnosis was one of pagetoid cutaneous T-cell lymphoma, also known as Woringer-Kolopp disease. Despite treatment with methotrexate and carmustine, the ulcer worsened rapidly within two months. Subsequent biopsy revealed epidermal and dermal infiltration with large cells of identical phenotype to that seen in the previous biopsy, with angiocentrism and expression of Ki67 in over 90% of cells, pointing to a diagnosis of AECL. Progression to disseminated ulceronecrotic lesions occurred rapidly, and the patient died of sepsis within a few months. Discussion. AECL is characterised by ulcerative-haemorrhagic lesions that develop aggressively without any preceding mild cutaneous lesions. Median survival is 12 months. Histological analysis shows pagetoid epidermotropism comprising large monomorphic CD8+, CD2- and CD5- cells with markers for cytotoxicity and high expression of Ki67. The initial indolent phase in the case we report herein accounts for the diagnostic confusion at the outset with Woringer-Kolopp disease. Negative status of CD2 and CD5 labels may allow prompt diagnosis of AECL. (C) 2016 Elsevier Masson SAS. All rights reserved.