Adult T-cell Leukemia/Lymphoma



Adult T-cell Leukemia/Lymphoma


Aaron Auerbach, MD, PhD










This clinical photograph shows an ulcerating lesion image, which is 2.5 cm in greatest dimension, from the foot of a person from the Caribbean region with ATLL, HTLV-1(+).






This ATLL involves the mucosa. Note the small lymphocytes with irregular hyperchromatic nuclei infiltrating squamous mucosa, forming Pautrier-like microabscesses image. (Courtesy C. Bueso-Ramos, MD.)


TERMINOLOGY


Abbreviations



  • Adult T-cell leukemia/lymphoma (ATLL)


Synonyms



  • Adult T-cell leukemia


Definitions



  • T-cell lymphoma/leukemia of regulatory T cells (CD4[+], CD25[+], FOXP3[+]) caused by human T-cell leukemia virus type 1 (HTLV-1)


ETIOLOGY/PATHOGENESIS


Infectious Agents



  • Human T-cell leukemia virus type 1



    • Progresses to leukemia/lymphoma in < 5% of infected individuals


    • Long latency period



      • Most exposed as infants/children


      • Tumor often after 20 years of viral exposure


    • Transmitted through blood or breast milk


    • Also causes tropical spastic paraparesis


    • Encodes Tax (a viral oncoprotein)



      • Plays a role in development of ATLL


      • Activates transcription factors for T-cell proliferation genes


CLINICAL ISSUES


Epidemiology



  • Age



    • Adults, most commonly in 50s or 60s


  • Gender



    • Male:female = 1.5:1.0


  • Ethnicity



    • Endemic to southwest Japan, Caribbean islands, South America, and central Africa


Presentation



  • Skin lesions



    • Develop in 50% of ATLL patients


    • Usually multiple nodules/tumors, papules, plaques, or macules



      • Papules may cover large segments of body


    • Rarely, erythroderma, purpura, prurigo, or erythema multiforme


  • Other sites of disease include lymph nodes, peripheral blood, bone, spleen and sometimes lung, liver, and CNS



    • Most patients have generalized lymphadenopathy


    • Hypercalcemia from increased osteoclast bone resorption


  • 4 clinical presentations: Acute, chronic, lymphoma, and smoldering



    • Acute subtype



      • Most common subtype


      • Severe peripheral blood lymphocytosis, ↑ WBC, ↑ LDH, skin lesions, lymphadenopathy


      • Hypercalcemia and lytic bone lesions


      • Immunodeficiency leads to other opportunistic infections


    • Chronic subtype



      • Lymphocytosis, but ↓ WBC than acute subtype


      • No hypercalcemia, exfoliative skin rash


    • Lymphomatous subtype



      • ↑ lymphadenopathy; usually no peripheral blood involvement


      • Less hypercalcemia than acute subtype; skin often involved


    • Smoldering subtype



      • > 5% tumor cells in peripheral blood, even though normal WBC count


      • Tumor cells small with less pleomorphism and lobation


      • No hypercalcemia or lymphadenopathy

Jul 8, 2016 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Adult T-cell Leukemia/Lymphoma
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