ALK-POSITIVE ANAPLASTIC LARGE CELL LYMPHOMA

Abstract

The WHO 2017 revised 4th edition classifies many different types of B cell lymphomas and T and NK cells lymphomas. ALK-positive (ALK+) anaplastic large cell lymphoma (ALCL) is a T cell lymphoma consisting of large lymphoid cells which have abundant cytoplasm and pleomorphic, often horseshoe-shaped nuclei, with chromosomal translocation involving the ALK gene and expression of ALK protein and CD30. ALK+ ALCL accounts for about 5% of all non-Hodgkin lymphomas, 50% to 60% of ALCL and 10% to 15% of children’s non-Hodgkin lymphomas. We present 23 years old man with single painful ulcerative growth at left buccal mucosa. The biopsy tissue shows characteristic of large cells lymphoma with the neoplastic hallmark cells. The tumour cells are positive for CD3, CD30, EMA, ALK, CD4, and TIA1. CD30 staining pattern is typically on the cell membrane and Golgi region of the neoplastic cells. ALK expression is on both nucleus ad cytoplasmic. The tumour cells are negative for CD5, CD8, CD20. Ki67 proliferation index is high, about 90% of tumour cells expressed and it matched with Anaplastic large cell lymphoma, ALK positive. Morphology is important, but immunophenotyping are also mandatory in Lymphoma diagnosis to know their specific characteristic. The precise classification of lymphoma entities has facilitated by combination of morphology, immunophenotyping and genetic features.