Leucemia/linfoma de células T do adulto

Abstract

A leucemia/linfoma de células T do adulto (ATL) é tipo agressivo de doença linfoproliferativa causada pelo vírus linfotrópico para células T humanas (HTLV-I), geralmente fatal e que não responde a quimioterapia. Classifica-se em formas aguda, crônica, linfomatosa e indolente (smoldering). Outra forma clínica, a tumoral primária de pele, com características diferentes, foi sugerida recentemente. As formas aguda, linfomatosa e tumoral primária de pele são as de pior prognóstico. Os critérios diagnósticos de ATL são: sorologia positiva para o HTLV-I; diagnóstico citológico ou histológico de leucemia/linfoma de células T, CD4+/CD25+; presença de linfócitos T anormais em sangue periférico; confirmação de integração monoclonal do DNA proviral do HTLV-I. Há lesões de pele em cerca de 70% dos casos,que podem ser primários (formas indolente e tumoral primária da pele) ou secundários. As lesões cutâneas são múltiplas, sendo as mais freqüentes a eritrodermia, as pápulas e as placas. A ATL não tem aspecto histológico característico, podendo apresentar padrões superponíveis ao linfoma periférico T não especificado, à micose fungóide ou ao linfoma anaplásico de grandes células. O padrão imuno-histoquímico pode também simular o de outros tipos de linfoma T. Por esse motivo, é muito importante que no Brasil seja solicitada sorologia para o HTLV-I em todos os casos de leucemia e/ou linfoma de células T maduras.

Epidemiology, Treatment, and Prevention of Human T-Cell Leukemia Virus Type 1-Associated Diseases

“…ATL is generally categorized into four forms: acute, chronic, smoldering, and lymphoma types (89,96). In a Brazilian ATL series of cases, 67% of the individuals had cutaneous lesions (6).…”

“…Lesions observed for chronic and smoldering variants of ATL can be similar to those seen for mycosis fungoides patients. (6,96,100). Monoclonal integration of provirus DNA is mandatory as diagnostic proof of chronic and smoldering ATL, since the histopathological characteristics of both are similar to those seen for mycosis fungoides (6).…”

“…(6,96,100). Monoclonal integration of provirus DNA is mandatory as diagnostic proof of chronic and smoldering ATL, since the histopathological characteristics of both are similar to those seen for mycosis fungoides (6). Many types of skin lesions have been related to HTLV-1, such as macular, papular, nodular, and tumoral lesions, with erythema, desquamation, and erythroderma.…”

“…Many types of skin lesions have been related to HTLV-1, such as macular, papular, nodular, and tumoral lesions, with erythema, desquamation, and erythroderma. The skin involvement in an otherwise asymptomatic individual carrying HTLV-1 may be an indicator of smoldering ATL (6,30).…”

Cutaneous manifestations associated with HTLV‐1 infection

“…6 It is always important to evaluate whether the skin involvement in lymphoma is primary or secondary, since clinical behavior and prognosis are quite different. 25 It should be emphasized that HTLV-1 infection in carriers or patients with HAM/TSP may lead to erythematous, inflammatory, noninfectious and non-lymphomatous skin lesions, often with a histological suspicion of malignancy. Survival is longer in cases of primary cutaneous smoldering ATLL and histology is indicative of a better prognosis (predominance of MF morphology and low proliferative index) compared to the primary cutaneous tumoral type (Table 2), highlighting the importance of making a clear distinction between these two types of primary cutaneous ATLL.…”