Atypical Leukemia Accompanied by Vitamin B₁₂ Deficiency

Abstract

A 76 year old female with atypical leukemia complicated by vitamin B₁₂ deficiecy demostrated marked fluctuation in blast percentage and hemopoiesis over 8 month period. She underwent surgical removal of pancreas head cancer 5.5 years ago. In January 1989 severe pancytopenia and mild increase of bone marrow blasts were found. Blood transfusions and inadvertent administration of Vitamin B₁₂ resulted in alleviation of pancytopenia and decrease in blast percentage. Several months later her bone marrow blast exceeded 30%, when serum B₁₂ concentration was below 90 pg/ml. B₁₂ injection and blood transfusion resulted in significant improvement in her hematological condition, but shortly thereafter she died of fulminant hepatitis. Her bone marrow cells showed a polyclonal constitution, as assessed by the RFLP-methylation technique using the PGK gene as a probe. The coexistence of leukemic- and normal clones under Vitamin B₁₂ deficiency conditions and the differing behavior of such clones to B₁₂ supplementation may explain the unusual clinical course observed in this patient.