H. Shibayama et al., EARLY AGE ONSET OF HAIRY-CELL LEUKEMIA PRESENTING WITH LEUKOCYTOSIS, International journal of hematology, 64(3-4), 1996, pp. 287-290
Hairy cell leukemia (HCL) is an uncommon type of chronic B cell leukem
ia mainly affecting middle-aged adults. HCL presenting with pancytopen
ia is rare in Japan and a distinct subtype of HCL termed HCL-Japanese
Variant is predominantly seen. We describe a HCL patient with unusual
presentation. The patient was a 26-year-old male, such early onset of
HCL being quite rare. The patient showed leukocytosis with many circul
ating hairy cells and cellular bone marrow. These findings were prefer
entially seen in HCL-Japanese variant, but, cytomorphologic, cytochemi
cal and immunophenotypical studies on the pathologic cells were consis
tent with those of typical HCL seen in Western countries. Interferon-c
r therapy was very effective in this case. Differentiation of the subt
ype of HCL appears to be important for the choice of the treatment. Th
e cytological findings were useful for the differential diagnosis of H
CL presenting with leukocytosis.