Leukaemia cutis and leukaemic vasculitis.

BACKGROUND: Leukaemia cutis (LC) and leukaemic vasculitis (LV) are uncommon but important features of haematological malignancy.
OBJECTIVES: We aimed to evaluate clinicopathological features of a series of such cases.
METHODS: Thirty-four patients with LC were studied. Nineteen had acute myeloblastic leukaemia, six had acute lymphoblastic leukaemia, three had myelodysplastic syndrome-refractory anaemia with excess blast in transformation, three had non-Hodgkin's lymphoma in leukaemic phase, two had chronic lymphocytic leukaemia and one had multiple myeloma.
RESULTS: Cutaneous lesions were widely dispersed in 15 patients, but were restricted to the extremities in eight patients. In other patients lesions were localized on the face, hands and feet. Cutaneous lesions were generally erythematous, maculopapular, squamous, nodular, haemorrhagic or necrotic. Two localizations were very interesting: in one case, lesions were confined to the site of previous varicella zoster virus infection; in the other case, leukaemic infiltration occurred within a lesion of cutaneous leishmaniasis. All of the patients had high white blood cell count and/or other findings of high tumour burden. Vasculitis with leukaemic cell infiltration (LV) was detected in 24 patients, and was high-grade LV in 16 patients. Patients with high-grade LV tended to have a higher white blood cell count and other findings associated with an aggressive clinical course compared with patients not having LV. Thirteen patients with LV died within 1 month but five patients lived more than 1 year.
CONCLUSIONS: LC, and especially LV, is generally an indicator of poor prognosis. Its pathogenesis must be evaluated further with additional studies, including adhesion molecules, angiogenic factors and other biological parameters.