Acute Lymphoblastic Leukemia with Mature Appearing Lymphocytes: First Chinese Case Report and Literature Review

Objective: To increase the knowledge and understanding of acute lymphoblastic leukemia with maturation(ALLm).

Method: One ALLm case with clinical manifestation, bone marrow morphology, immunophenotype and cytogenetic results were presented and related literatures were reviewed.

Result: The patient was a fifty-five year old women, the haematological feature was Pancytopenia. There were 12% lymphoblasts and 82.5% mature appearing lymphocytes in the bone marrow smear. The mature appearing leukemic cells could not be separated clearly by gating. However, the immunophenotypes of mature-appearing leukemic cells(Low FSC and Low CD45) and lymphoblasts were the same. Both results were CD33+CD34+CD19+CD22+HLA−DR+CD5−CD7−CD10−CD13−CD14−CD15−CD20−CD25−CD45−CD71−CD11b−CD103−CD117−. Bone marrow biopsy showed hypercellularity with diffuse infiltration of lymphocytes, The results were CD34++,TdT++,Pax-5+++,CD43++,CD3+(scatter),CD5+(scatter),CD20−,CD10+,CyclinD1−, lymphoblasts Ki67+, mature-appearing leukemic cells ki-67-. FISH analysis of the bone marrow revealed about 1% cells with a signal pattern suggesting loss of one copy of chromosome 8. After VDP, MA, AAG and HAG regimens Complete remission was not achieved.

Conclusion: ALLm is a special morphological variant of acute lymphoblastic leukemia, most mature appearing cells are in resting G0 phase and this could be the reason why ALLm has a poor response to chemotherapy.