[Granulocytic sarcoma: unusual form of presentation for acute nonlymphoblastic leukemia].

A case of acute non-lymphoblastic leukaemia is reported which appeared as granulocytic sarcoma (GS) with no leukaemic expression in peripheral blood. Aside of the patient's advanced age, the rarity of this entity at the onset of ANLL and the location of the tumour, on the back of the patient's left upper thigh are outstanding features. The difficult diagnosis of such non-leukaemic cases is also stressed here, with regard to the differential diagnosis with non-Hodgkin's lymphoma (NHL). It is concluded that the incidence of GS as a tumour of soft tissues in the extremities is more common in patients over 75 years of age, its frequency being 17-fold that of NHL for the same age and location.