A Rare Case Report from the Umbrella of T-Cell Lymphomas

Abstract

Introduction: Angioimmunoblastic T-cell lymphoma (AITL) is an uncommon subtype of mature peripheral T-cell lymphoma (PTCL). According to the 2016 World Health Organization classification of lymphoid neoplasms, AITL resides under the umbrella of nodal T-cell lymphomas with follicular T helper phenotype. Angioimmunoblastic T-cell lymphoma (AIL-TCL) is a rare subtype of lymphoma, making up only 1% to 2% of non-Hodgkin’s lymphomas and about 10% of PTCL according to a recent study.

Case Report: 45-year-old male patient came to our OPD with history of Cervical and Axillary Lymphadenopathy since 4 months. Patient also had vague complaints of fatigue and on & off fever since 1 month. CBC showed Microcytic Hypochromic Anemia along with few atypical lymphocytes in the peripheral smear. FNAC of the Cervical and Axillary lymph node was reported as Small Lymphocytic Lymphoma (SLL) and Necrotizing Lymphadenitis respectively. Cervical lymph node excision was done and sent for HPR and diagnosed as AITL.

Methods: Grossing was done after formalin fixation. Processed in automated tissue processor. H & E staining was performed and morphology was examined under light microscope. Further IHC marker staining was performed for definitive diagnosis and subtyping.

Results: H & E –effaced nodal architecture with intact capsule and focal preservation of sinuses. The follicles are ill-defined with burnt-out germinal centres.

       IHC -- Neoplastic cells express(Positive) :

                  CD 45, CD 3, CD 2, CD 5, CD 4 > CD 8.

              -- Negative for :

                  CD 20, CD 10, BcL-6, Cyclin D1.

              -- CD 23 highlights the Follicular Dendritic cells.

              -- BcL-2 is seen around the Germinal centres.

              -- Ki 67 is approx. 40 % in Inter-follicular area and high in the Germinal centres.

Discussion: Histopathologically, diagnosis of AITL is difficult and challenging due to various patterns and immunohistochemistry resolves the issue. Providing prompt and early diagnosis is mandatory for institution of therapy with combination chemotherapy to improve survival as evidenced in literature.

Conclusions: AITL is a neoplastic disease, categorized under Peripheral T-cell Lymphoma, accounting for 15% of T-cell lymphomas. Morphology can be deceptive, hence IHC staining is mandated for a definitive diagnosis.

Keywords: Angioimmunoblastic T-cell lymphoma (AITL), Immunohistochemistry (IHC), peripheral T-cell lymphoma (PTCL).