Inclusion Criteria:

* Patients must be newly diagnosed with a clinical diagnosis of acute promyelocytic leukemia initially by morphology (bone marrow or peripheral blood); bone marrow is highly preferred but in cases where marrow cannot be obtained at diagnosis, peripheral blood will be accepted; APL is considered a hematological emergency and treatment should be initiated as quickly as possible without waiting for molecular or cytogenetic/fluorescence in situ hybridization (FISH) confirmation; for patients who are unable to begin receiving ATRA in a timely manner following a presumed diagnosis of APL, consideration should be given to initiating ATRA and proceeding with treatment outside of the AAML0631 protocol; if the RQ-PCR results are known at the time of study enrollment, the patient must demonstrate PML-RARA and/or RARA-PML transcripts by RQ-PCR to be eligible; patients without evidence of APL by bone marrow or peripheral blood morphology but with isolated myeloid sarcoma (myeloblastoma; chloroma, including leukemia cutis) are eligible provided that the t(15;17) translocation is documented on either marrow or tumor tissue by cytogenetics, FISH, or PCR prior to study enrollment; in this situation, touch preps from the tumor site can be evaluated by FISH with PML-RARA probes; NOTE: A lumbar puncture is not required to be enrolled on study; if the diagnosis of APL is known or suspected, extreme caution must be exercised in performing a lumbar puncture during active coagulopathy; in addition a computed tomography (CT) or magnetic resonance imaging (MRI) should be considered to rule out the possibility of an associated chloroma if central nervous system (CNS) disease is suspected or proven; if CNS disease is documented, patients are still eligible
* No minimal performance status criteria
* The patient must not have received systemic definitive treatment for APL or other suspected leukemia, including cytotoxic chemotherapy, retinoids, or arsenic; prior therapy with corticosteroids, hydroxyurea, or leukopheresis will not exclude the patient; if a patient received intrathecal cytarabine prior to the diagnosis of APL being known, the patient will still be eligible as long as they meet all other eligibility requirements

Exclusion Criteria:

* Pregnant women or nursing mothers are excluded; treatment under this protocol would expose an unborn child to significant risks; patients should not be pregnant or plan to become pregnant while on treatment; women and men of reproductive potential should agree to use an effective means of birth control; there is an extremely high risk of fetal malformation if pregnancy occurs while on ATRA in any amount even for short periods
* Patients with a pre-existing prolonged QT Syndrome will not be eligible for this protocol due to the use of arsenic trioxide which can prolong the QT interval