A forty-three-year-old Thai man presented with acute fever and dyspnea for one week with bilateral
patchy infiltration, pancytopenia with monoblast. Bone marrow study was consistent with acute monoblastic
leukemia. Lung lesions rapidly progressed to acute respiratory failure, which required intubation. Bronchoscopy
with bronchoalveolar lavage revealed monotonous monoblast infiltration. Induction chemotherapy
with 7 + 3 regimen was administered to halt the progression of leukemic pulmonary infiltration. Although
there was clinical improvement, the chest radiograph developed crescent formation in the right upper lung
field. Invasive pulmonary aspergillosis was suspected and successfully treated with antifungal agent. After
peripheral blood recovery, bone marrow evaluation was performed and complete remission was established.
HLA matching was sent to prepare for hematopoietic stem cell transplantation (HSCT). The literature review
showed that the appropriate treatment for the patients with t(10;11)(p12;q23) was HSCT, but there was no
data concerning correlation of t(10;11)(p12;q23) and pulmonary infiltration. This may be due to the low
incidence of leukemic infiltration of acute leukemia patients, which is 0.48% and 3.06% in acute myeloid
leukemia and acute monoblastic leukemia, respectively.

Keywords: Acute monoblastic leukemia, Leukemic pulmonary infiltration, t(10;11)(p12;q23)