Juvenile chronic myelogenous leukemia: differentiation from infantile cytomegalovirus infection.

Differentiation between cytomegalovirus (CMV)-associated disease and juvenile chronic myelogenous leukemia (JCML) in infants excreting CMV may be difficult. It is important to make a prompt, definitive diagnosis since the management differs. A 3-month-old infant presented with clinical findings that mimicked both disorders and a plan was developed to make the correct diagnosis. Clonogenic assays and liquid cultures of patients' peripheral blood and bone marrow showed findings that are recognized as the hallmark of JCML, namely, impaired growth of normal hematopoietic progenitors, and excessive, autonomous proliferation of monocyte/macrophage elements. The urine was positive for CMV, and there was a significant rise in the anti-CMV antibody titer over 4 weeks, indicating a postnatal CMV infection. Despite this, freshly obtained and cultured marrow cells as well as a liver biopsy were negative for CMV by immunoassay, by anti-CMV monoclonal antibody testing, and by electron microscopy. Because of these results, the diagnosis of CMV infection was established but could not account for all of the abnormal clinical and hematological findings. Thus, the diagnosis of JCML was also substantiated and antileukemic therapy was initiated with confidence.