Palmar flexion creases in childhood neoplasia.

About 90% of Caucasian individuals in the general population may observe two transverse palmar flexion creases when their fingers are slightly bent. A small minority may find in one hand a single transverse crease or the usual two creases, of which one seems to cut across the palm to the ulnar margin. Those unusual creases are called simian- or Sydney-creases, respectively. Normal healthy people hardly ever observe them in both hands. We observed those unusual creases, however, in more than 50% of children suffering from different type of malignant neoplasia, quite often in both hands. The difference between patients and controls of similar ages is highly significant. Among patient with childhood acute lymphocytic leukemia the variant creases were mostly of the Sydney type. They most frequently occurred in those patients in whom the disease had become manifest at an early age. Since fathers as well as mothers of the patients showed significantly higher frequencies of unusual creases, the phenomenon seems to be a familial one. A most singular effect is the striking incidence of those creases in younger siblings of the patients. With regard to crease variance our data are essentially similar for lymphoproliferative disorders (ALL and NHML) and embryonic malignant tumors. This might be the first indication of a common host factor in patients with ALL or embryonic tumors occurring in early childhood. We have postulated that this factor may be a regulatory one associated with cellular growth and differentiation in early fetal palmar pads as well as with cell-mediated immune response to early pediatric tumors. The observation of palmar flexion creases may prove to be rewarding in future studies of cellular defense mechanisms in young patients with neoplasia.