We encountered a 76-year-old woman with acute myelogenous leukemia (AM
L) who developed Swell's syndrome. A biopsy specimen taken from her sk
in lesion on the upper arm showed an infiltration of numerous neutroph
ils intermingled with leukemic cells. As far as we know, this is the f
irst report of Sweet's syndrome showing a phenotypically identified le
ukemic cell infiltration of AML determined as M(2) in the French-Ameri
can-British classification.