RESUMO
Objective: To analyze the frequencies of histological types of lymphoma, diagnosed with complete immunohistochemical profile in younger and older age group
Study Design: Cross-sectional analytical study
Place and Duration of Study: Dow Diagnostic Research and Reference Laboratory, Dow University of Health Sciences, Karachi, from January 2009 to September 2013
Methodology: Consecutive cases of lymphomas, which were diagnosed using immunohistochemistry, were analyzed according to WHO classification. Frequency and percentages for different types of lymphomas were calculated. Hodgkin and non-Hodgkin lymphomas characteristics in two age groups of less than and more than 40 years were compared, applying chi-square test
Results: Out of the 318 cases, 79 [25%] were Hodgkin Lymphomas [HL] and 239 [75%] were Non-Hodgkin Lymphomas [NHL]. Mixed Cellularity Hodgkin Lymphoma [MCHL] was the commonest [n=48]. Amongst the NHL, 215 [89.95%] were B cell lymphomas and 24 [10.05%] were T-cell lymphomas. Diffuse Large B-Cell Lymphoma [DLBCL] was the commonest lymphoma [n=165, 69.95% of NHL]. Anaplastic T-Cell Lymphoma [ALCL, n=10] was the commonest T-cell lymphoma. The frequency of HL was significantly higher in the younger age group and that of NHL was higher in the older age group [p < 0.001]. Primary lymph node involvement was reported in 175 [55%] and cervical lymph node was the most frequent site. Extra nodal involvement was seen in 93 [29%] of all cases and was reported in 87 [36.4%] of NHL and 6 [7.5%] of HL. The most common extra nodal site was the gastrointestinal tract
Conclusion: Hodgkin lymphoma comprises 25% and non-Hodgkin lymphoma comprises 75% of all lymphomas. Both occur in younger age groups than reported in the West. B-cell NHL is three times more common than T-cell lymphoma. DLBCL is the most frequent lymphoma. ALCL is the most common T-cell, and mixed cellularity is the most common Hodgkin lymphoma