[Clinical manifestations and staging system]

Patients with chronic myeloid leukemia(CML) are often diagnosed after a routine blood examination when a raised leukocyte count is found. The disease is biphasic or triphasic. The initial chronic phase lasts on 2-6 years without severe symptoms. But ultimately it either changes abruptly to an acute crisis phase or an accelerated phase which later progresses to the acute crisis phase. The acute phase is refractory to treatment and has a median duration of 3 months. Clinical features of the accelerated phase and the acute crisis phase are very diverse. The classification for the phases of CML proposed by the International Bone Marrow Transplantation Registry is reasonable.