leukemia cutis

Introduction

Localized or disseminated skin infiltration by leukemic cells.

Etiology

• skin infiltration by leukemic cells
• occurs with both acute & chronic leukemias
• most commonly occurs in association with AML-M4 & AML-M5

Epidemiology

• <5% to 50% of leukemias, depending upon type
• any age, but more common in patients > 50 years
• no sex predilection

Clinical manifestations

• skin lesions may precede onset of systemic leukemia
• lesions generally arise over several days
• lesions are generally asymptomatic, but may be pruritic, tender or painful
• most common lesions are small 2-5 mm papules, nodules or plaques (always palpable)
• a variety of lesion morphologies are associated with each specific leukemia
• lesions are generally somewhat darker than surrounding skin, pink -> brown -> violaceous
• lesions may be hemorrhagic in patients with thrombocytopenia
• generalized distribution of lesions, especially trunk, extremities & face
• gingival infiltration may occur with acute monocytic leukemia (AML-M5)
• 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

• complete blood count (CBC)
  • cell differential
  • peripheral smear
• bone marrow biopsy & aspirate
• skin biopsy
  • touch preparation
  • immunohistochemistry (immunophenotyping)

Differential diagnosis

• disseminated infection
• inflammatory disorders
  • pyoderma gangrenosum
  • Sweet's syndrome
• drug reaction
• transfusion-associated graft vs. host reaction
• vasculitis
• erythema multiforme

Management

• therapy directed at the leukemia itself
• local electron-beam therapy
• PUVA

More general terms

• leukemia
• skin disease (dermatologic disorder, dermatopathy, dermatosis)