Adult T cell leukemia: a typical case from India

Multifaceted adult T-cell leukemia/lymphoma in India: a case series

Background:

Adult T-cell leukemia/lymphoma (ATL) is caused by human T-cell lymphotropic virus type-1 (HTLV-1). India is considered as a nonendemic region for HTLV-1. Recent upsurge of cases have been noted in southern parts of India.

Aims and objectives:

The objective was to describe skin manifestations in various types of ATL.

Materials and Methods:

Clinical examination, blood investigations, skin biopsies, lymph node biopsies, and immunohistochemistry were performed in five patients. Flow cytometry was performed in two cases.

Results:

Serological testing was positive for HTLV-1 in all patients. All patients presented with skin lesions. Rare presentations of molluscum contagiosum like papules, purpuric macules and plaques, hypopigmented macules and verrucous papules were seen. Dermatophytic infections occurred in two patients. Mucosal lesion was seen in one patient. Histological features include dermal lymphoid infiltrate with or without epidermotropism. Presence of epidermotropism did not correlate with the severity of disease. All patients except one succumbed to illness within few months to 1 year period.

Conclusions:

ATL manifest in myriad presentations and skin lesions are often the earliest manifestation. Cutaneous manifestations of ATL vary from subtle hypopigmented macules to florid nodular lesions, and HTLV-1 screening need to be carried out in all doubtful cases.

Epidemiological Aspects and World Distribution of HTLV-1 Infection

The human T-cell leukemia virus type 1 (HTLV-1), identified as the first human oncogenic retrovirus 30 years ago, is not an ubiquitous virus. HTLV-1 is present throughout the world, with clusters of high endemicity located often nearby areas where the virus is nearly absent. The main HTLV-1 highly endemic regions are the Southwestern part of Japan, sub-Saharan Africa and South America, the Caribbean area, and foci in Middle East and Australo-Melanesia. The origin of this puzzling geographical or rather ethnic repartition is probably linked to a founder effect in some groups with the persistence of a high viral transmission rate. Despite different socio-economic and cultural environments, the HTLV-1 prevalence increases gradually with age, especially among women in all highly endemic areas. The three modes of HTLV-1 transmission are mother to child, sexual transmission, and transmission with contaminated blood products. Twenty years ago, de Thé and Bomford estimated the total number of HTLV-1 carriers to be 10-20 millions people. At that time, large regions had not been investigated, few population-based studies were available and the assays used for HTLV-1 serology were not enough specific. Despite the fact that there is still a lot of data lacking in large areas of the world and that most of the HTLV-1 studies concern only blood donors, pregnant women, or different selected patients or high-risk groups, we shall try based on the most recent data, to revisit the world distribution and the estimates of the number of HTLV-1 infected persons. Our best estimates range from 5-10 millions HTLV-1 infected individuals. However, these results were based on only approximately 1.5 billion of individuals originating from known HTLV-1 endemic areas with reliable available epidemiological data. Correct estimates in other highly populated regions, such as China, India, the Maghreb, and East Africa, is currently not possible, thus, the current number of HTLV-1 carriers is very probably much higher.