Long-term control of refractory follicular lymphoma after treatment of secondary acute promyelocytic leukemia with arsenic trioxide (As2O3) and all-trans retinoic acid (ATRA)

Although BM metastasis is commonly found in CRMAHA, it is seldom an initial presenting feature of malignant tumor. BM metastasis from colon cancer is very rare, particularly when encountered in the absence of usual distant metastases such as liver and lungs [8-10]. Generally, BM study is not routinely considered in solid tumor workup; however, PB slide examination is performed in almost all known or suspected cancer cases as a simple screening tool. One of the well-known PB findings suggestive of BM involvement of malignancy is leukoerythroblastic reaction. Although leukoerythroblastic reaction is not specific for malignant conditions, its presence accompanied by MAHA could be a strong indicator of BM examination in cases with unexplained cytopenia [10]. Chemotherapy is the only effective treatment for CRMAHA. Although the prognosis of CR-MAHA is generally poor, several studies reported cases of favorable response of CR-MAHA to chemotherapy [2, 4, 5]. As MAHA is not a common presenting sign of cancer recurrence, early recognition of this rare presentation and prompt investigation including BM study are essential for timely management.