leukemia cutis

Localized or disseminated skin infiltration by leukemic cells. Etiology: 1) skin infiltration by leukemic cells 2) occurs with both acute & chronic leukemias 3) most commonly occurs in association with AML-M4 & AML-M5 Epidemiology: 1) <5% to 50% of leukemias, depending upon type 2) any age, but more common in patients > 50 years 3) no sex predilection Clinical manifestations: 1) skin lesions may precede onset of systemic leukemia 2) lesions generally arise over several days 3) lesions are generally asymptomatic, but may be pruritic, tender or painful 4) most common lesions are small 2-5 mm papules, nodules or plaques (always palpable) 5) a variety of lesion morphologies are associated with each specific leukemia 6) lesions are generally somewhat darker than surrounding skin, pink -> brown -> violaceous 7) lesions may be hemorrhagic in patients with thrombocytopenia 8) generalized distribution of lesions, especially trunk, extremities & face 9) gingival infiltration may occur with acute monocytic leukemia (AML-M5) 10) less common manifestations: -> ecchymoses, palpable purpura, ulcerative lesions, erythroderma, bullous lesions, gingival hypertrophy, arciform lesions, lesions resembling pyoderma gangrenosum, urticaria, urticaria pigmentosa, Guttate psoriasis Laboratory: 1) complete blood count (CBC) a) cell differential b) peripheral smear 2) bone marrow biopsy & aspirate 3) skin biopsy a) touch preparation b) immunohistochemistry (immunophenotyping) Differential diagnosis: 1) disseminated infection 2) inflammatory disorders a) pyoderma gangrenosum b) Sweet's syndrome 3) drug reaction 4) transfusion-associated graft vs. host reaction 5) vasculitis 7) erythema multiforme Management: 1) therapy directed at the leukemia itself 2) local electron-beam therapy 3) PUVA

General

leukemia skin disease (dermatologic disorder, dermatopathy, dermatosis)

References

Color Atlas & Synopsis of Clinical Dermatology, Common & Serious Diseases, 3rd ed, Fitzpatrick et al, McGraw Hill, NY, 1997, pg 566-569