Adult T-cell leukemia/lymphoma
Sean Klepper M.D.
Artur Zembowicz M.D....
- An aggressive lymphoproliferative disorder caused by infection with the virus HTLV-1, which is endemic in Japan, the Caribbean, South America and central Africa
- The lifeteme risk of developing ATLL among individuals infected with HTLV-1 is 2.5%.
- Four clinical forms: acute, chronic, smoldering and lymphoma
- The acute form presents with high-grade leukemia, marrow involvement, skin lesions, generalized lymphadenopathy ane hepatosplenomegaly.
- Characteristic of all forms is hypercalcemia, extreme thirst and circulating CD25 (IL-2 receptor; HTLV-1 infects CD4+ T-cells by way of this receptor)
- Diagnosis is based upon clinical features with serologic demonstration of anti-HTLV-1 antibodies.
- Cutaneous manifestations are variable, and can include generalized erythroderma, a maculopapular rash, nodules, plaques and bullous lesions.
- Dense lymphoid infiltrate throughout the dermis and subcutaneous fat
- The infiltrate is often most dense around blood vessels and skin appendages.
- Exocytosis into the epidermis, with or without Pautrier's microabscesses, often occurs.
- The neoplastic lymphocytes range in size from small to large and have markedly convoluted nuclei.
- There is often marked dermal edema.
- Vasculitis with red blood cell extravasation is often seen.
- Circulating leukemic cells have large convoluted nuclei said to resemble a flower with petals ("flower cells")
- Immunophenotypically, the cells are helper T-cells (CD3+, CD4+, CD5+, CD8+), usually with loss of CD7 and characteristic expression of CD25.