Burkitt's lymphoma in Uganda: the role of immunohistochemistry in diagnosis.

BACKGROUND Haematoxylin and eosin staining has remained the standard diagnostic method for Burkitt's lymphoma. Ancillary tests including immunohistochemistry, not widely available in developing countries, are important tools in verifying the diagnosis of lymphomas with equivocal morphological findings. OBJECTIVE To evaluate the reliability of haematoxylin and eosin staining in the diagnosis of Burkitt's lymphoma using immunohistochemistry as the gold standard. DESIGN Cross sectional study. SETTING Department of Pathology laboratory, Makerere University Medical School, Uganda. SUBJECTS One hundred and thirty eight formalin fixed paraffin embedded biopsies of Burkitt's lymphoma diagnosed from January 2001 to December 2005. RESULTS Of the 138 tumours, 88.4% were extra-nodal: jaw 36.2%, ovary 21%, gastrointestinal tract 12.3% other abdominal 11.6%. Males (55.8%) predominated. The sensitivity and specificity of haematoxylin and eosin were 93.2% and 50% respectively. The positive and negative predictive values were 91.7% and 55.6%. CONCLUSION Histology using haematoxylin and eosin staining is sensitive in the diagnosis of Burkitt's lymphoma but not very specific. Immunohistochemical staining with CD20, Ki-67 and bcl-2 is necessary for difficult cases.