DIAGNOSTIC UTILITY OF IMMUNOHISTOCHEMISTRY IN SUBTYPING ACUTE LYMPHOBLASTIC LEUKEMIA: A 2 YEARS’ EXPERIENCE

Abstract

OBJECTIVE: To determine the diagnostic importance of immunohistochemistry (IHC) in classifying acute lymphoblastic leukemia (ALL) in a tertiary care center.METHODS: This cross-sectional descriptive study was done from January-2017 to December-2018 at Rehman Medical Institute, Peshawar, Pakistan. Out of 133 cases diagnosed as precursor lymphoid leukemia, two cases were excluded due to inadequacy of the aspirate smears and 131 cases were included in the study. The immune-phenotype was detected by IHC with immune-markers viz terminal deoxynucleotidyl transferase (TdT), CD34, CD10, CD79a, CD3, myeloperoxidase (MPO), CD117 and paired box protein 1 (PAX1). RESULTS: Out of 131 cases included 99 (75%) were males and 32 (25%) were females. Mean age of the study participants was 20±16 years (range=16-65 years). Majority of the cases presented with hepatomegaly (n=113/131, 87%), followed by pallor (n=105/131, 80.1%), splenomegaly (n=89/131, 68%) and lymphadenopathy (n=82/131, 63%). Based on IHC, 114 (87.02%) cases were successfully classified to specific subtypes and 17 (13%) cases could not be assigned into any subtype. Eighty-six cases (65.7%) were of Pre-B cell ALL, 17 (13%) cases were T-cell ALL, 8 (6.1%) cases were Pre-T cell ALL while 3 (2.3%) cases were Pro-B lineage.CONCLUSION: Study concludes that majority of the patients were male and presented with hepatomegaly and pallor. IHC is effective method to sub-classify ALL into various immune-phenotypes in low resource countries where flow cytometry is unavailable. Pre-B cell ALL is common than T-cell ALL. KEY WORDS: (MeSH); (Non-MeSH); (MeSH); (MeSH), (MeSH); (MeSH); (MeSH); (MeSH)