CASE REPORT - T/NK LYMPHOMA

Less than 10% of chronic lymphoproliferative diseases are caused by T lymphocytes and NK cells. In addition to their rarity, the greatest obstacles to their identification have been the diversity and phenotypic complexity of these cells. Extranodal T/NK cell lymphomas are more common in adult men (mean age 44-54 years), originate from NK cells (or in some cases from cytotoxic T lymphocytes), and cause extensive vascular damage with prominent necrosis. They are strongly associated with Epstein-Baar virus (EBV) infection and involve the upper aerodigestive tract (mainly nasal cavity), skin, and lymph nodes. It is a highly aggressive lymphoma, with low survival rates and poor response to treatment. Male patient, 42 years old, starts with cervical and inguinal lymph node enlargement. Underwent PET-CT on 04/28/23: lymph node enlargement in the inguinal, iliac, pericaval, left paraaortic, retrocrural regions, in pulmonary hila and various compartments of the mediastinum, axillary and cervical, in addition to diffuse hypermetabolism in the bone marrow and splenomegaly. Performed inguinal lymph node biopsy on 05/05/23 – Immunohistochemistry released on 05/21/23 – Pathological cells positive for BCL2 CD10 CD4 CD5 CD7 CD8 Tdt, KI67+100%, diffuse CD3+, cytoplasmic pattern. Evolved with progressive worsening of the clinical condition and pancytopenia. Bone marrow aspirate collected on 05/26/23 for Immunophenotyping showing: 4.1% CD56+ CD3(-) CD8-/+ CD4(-) NK CELLS; 15% MATURE (CD45++) POLYCLONAL T LYMPHOID CELLS (CD3++): . 3.8% CD4+ TCRALFA/BETA+ (TCRCBETA1+ 50%); . 8.8% CD8+ TCRALFA/BETA+ (TCRCBETA1+ 20%); . 0.5% CD8+ TCRGAMA/DELTA+; . 1.3% CD4+CD8+ TCRALFA/BETA+ (TCRCBETA1+ 30%); . 0.6% DOUBLE-NEGATIVE: 0.1% TCRALPHA/BETA+ AND 0.5% TCRGAMA/DELTA+ 11.3% MATURE CD8+ LYMPHOID CELLS (CD45++), WITH PARTIAL EXPRESSION OF SURFACE CD4 AND CD3, EXPRESSION OF CYTOPLASMIC CD3+ (EPSILON CHAIN), T MARKERS (CD2+ CD5+ CD7+) AND CYTOTOXIC/NK ANTIGENS (CD56+ CD16-/+ CD94+ Perforin+), and effector T cell phenotype (CCR7(-) CD27-/+ CD28-/+ CD45RA+ homogeneous). NK profile stage 4: CD56++ CD16-/+ and CD57(-) (Figure 1).