Acute lymphoblastic leukemia of the skin and subcutaneous tissues; the first manifestation of disease in a 6-month-old infant: a case report with literature review.

Leukemic infiltrate involving the skin and subcutaneous tissue was the first manifestation of disease in a 6-month-old female infant. Knowledge of age-related distribution patterns of the red (cellular) and yellow (fatty) marrow is crucial for the interpretation of magnetic resonance imaging (MRI) studies. Diffusely decreased signal intensity throughout the bone marrow on the T1-weighted images specifically involving the epiphyseal ossification centers in infants 6 months after their appearance should be suggestive of a marrow infiltrative/replacement process. Correlation with the peripheral blood smear and bone marrow aspirate are necessary for the diagnosis of leukemia.