An adult with common acute lymphoblastic leukaemia (C-ALL) presenting with skin infiltration. A 22-year-old man presented with multiple raised erythematous skin lesions, pyrexia and epistaxis. A diagnosis of common acute lymphoblastic leukaemia (C-ALL) was made by morphological, cytochemical, immunological and cytogenetic examination of peripheral blood and bone marrow. Biopsy of the skin revealed leukaemic infiltration by similar cells. 