B lymphoblastic leukemia with granules mimicking acute myeloid leukemia in a 4 years female child

Abstract

Granular acute lymphoblastic leukemia [ALL] is a rare morphological variant of ALL characterized by cytoplasmic azurophilic granules or inclusions positive for aspecific esterase and acid phosphatase with heterogeneous features at the ultrastructural level. Granular ALL usually occur in children [2-7%] but is extremely rare in adults. It is important to perform cytochemical staining and flow cytometry to make the distinction between acute myeloid and lymphoblastic leukemia. We review the case history and pathological findings in a 4 years female child with initial cytomorphological diagnosis of AML which after flow cytometry turned out to be granular ALL.