CD5 Positive B Lymphoblastic Leukemia: Report of a Case with Review of Literature.

We report a rare CD5 positive B cell acute lymphoblastic leukemia (B-ALL) with a review of the clinopathological features and prognosis of previously reported cases in the literature. The aberrant expression of CD 5 antigen is uncommon in B-ALL; the morphological differential diagnosis includes blastic mantle cell lymphoma, denovo CD5(+) diffuse large B cell lymphoma and secondary diffuse large cell lymphoma/Richter's transformation. CD5(+) B cell ALL is commonly reported in younger patients (<18 years). Though the expression of T cell antigens is reported to have poor prognosis, the experience with CD5(+) B-ALL is limited to draw any firm conclusion regarding its prognosis.