Leukemia Cutis



Leukemia Cutis


Jeremy C. Wallentine, MD










Clinical image shows 2 small papules in a patient with acute myeloid leukemia. Histologic examination confirmed leukemic infiltrates consistent with myeloid sarcoma. (Courtesy V. Tonkovic-Capin, MD.)






A punch biopsy shows leukemic infiltrates in the superficial and deep dermis, extending into the subcutaneous adipose tissue. Sparing of the epidermis with a thin Grenz zone image is noted.


TERMINOLOGY


Abbreviations



  • Leukemia cutis (LC)


Synonyms



  • Myeloid sarcoma (MS), granulocytic sarcoma, extramedullary myeloid cell tumor, chloroma



    • When composed of myeloid cells


  • Monoblastic sarcoma



    • When composed of monocytic precursors


  • Primary extramedullary leukemia


Definitions



  • Clinically identifiable cutaneous lesions secondary to cutaneous infiltration by neoplastic leukocytes (myeloid or lymphoid)


  • Leukemia cutis commonly used to describe lymphocytic leukemias involving skin



    • Designated by precursor B- or T-cell lineage and chronic lymphocytic leukemia


    • “Myeloid sarcoma” is preferred term when leukemic cells are of myeloid or monocytic lineage


ETIOLOGY/PATHOGENESIS


Mechanisms of Skin Homing



  • Underlying process has not been defined



    • May involve coexpression of cutaneous lymphocyte antigen (CLA) and its interaction with specific chemokines


    • Other factors may include CCR4, TARC, and CCL22


  • Predilection for sites with cutaneous inflammation (e.g., Sweet syndrome, psoriasis)


CLINICAL ISSUES


Epidemiology



  • Incidence



    • Acute monocytic, myelomonocytic, and T-cell leukemias show highest incidence of leukemia cutis


    • LC can be observed in all forms of acute myeloid leukemia (AML)


    • Occurs in 10-15% of patients with AML



      • Varies widely with AML subtype


      • Up to 50% of patients with acute myelomonocytic and monocytic types


    • Less frequent in patients with myeloproliferative and myelodysplastic neoplasms



      • Rare reports of CML with LC presentation


      • Usually related to disease progression &/or transformation


    • Is seen in up to 25% of chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) cases


    • Occurs in 20-70% of mature T-cell leukemias



      • 40-70% of adult T-cell leukemia/lymphoma (ATLL)


      • 25-30% of T-cell prolymphocytic leukemia (T-PLL)


    • Unusual in patients with precursor B- or T-cell lymphoblastic leukemia/lymphomas (LBL) and plasma cell leukemia


    • Occurs in 25-30% of infants with congenital leukemia


  • Age



    • Frequency higher among children than adults


Site



  • Most commonly involves extremities (legs > arms)


  • Back, chest, scalp, and face may also be involved


  • Preferential involvement at sites of previous or concomitant inflammation



    • Sweet syndrome


    • Herpes zoster


    • Insect bites


    • Psoriasis


Presentation



  • Presentation may precede (aleukemic LC), coincide with, or manifest as recurrence of acute leukemia




    • Most cases present after diagnosis of systemic leukemia


    • < 10% present prior to blood or bone marrow involvement (aleukemic LC or primary extramedullary leukemia)


  • Single or multiple skin lesions



    • Violaceous, red-brown, or hemorrhagic papules, nodules, and plaques of varying sizes


    • Erythematous papules and nodules most commonly reported


    • Eczematous lesions


    • Ulcers


    • “Blueberry muffin” appearance



      • Firm blue, red, or purple nodules in generalized distribution


      • Term historically used to describe cutaneous involvement in children with congenital leukemia


  • Oral petechiae


  • Thickening of the gums



    • Oral lesions more common in adults



      • Rare in congenital leukemias


  • Other sites of extramedullary involvement are frequent (e.g., meninges)


Laboratory Tests



  • Lactate dehydrogenase and β2-microglobulin



    • Higher levels reported in patients with leukemia cutis


  • Serology for HTLV-1 in cases of ATLL


Treatment



  • Options, risks, complications



    • Managed by treating underlying leukemia



      • Systemic chemotherapy


      • Bone marrow transplantation


    • Local therapy (e.g., radiation)


    • Aleukemic LC should not be managed differently from patients with known leukemia


Prognosis



  • Poor prognosis



    • Generally a manifestation of disease progression


  • Leukemia cutis in context of congenital myelogenous leukemia is an exception



    • Not associated with worse prognosis


    • Spontaneous regression of LC without treatment has been observed


  • Prognosis in CLL patients is good



    • Exception of blastic transformation (Richter syndrome) is associated with poor prognosis


MICROSCOPIC PATHOLOGY


General Histologic Features



  • Low-power patterns of involvement



    • Perivascular &/or periadnexal


    • Dense and diffuse


    • Nodular


    • Subtle superficial interstitial infiltrate (rare)


  • Stromal fibrosis


  • Lineage assignment unreliable with histology alone

Jul 8, 2016 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Leukemia Cutis

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