(adult T-cell leukemia; hereinafter referred to as ATL)is T-cell leukemia lymphoma, caused by infection of (human T lymphotropic virus type 1: HTLV-1).This was discovered in Japan, and this was a first disease that provided evidence that human retrovirus caused tumorigenesis in humans. Regionally, they are commonly found in Japan, Caribbean states, and the West Coast of Africa. Regarding Japan HTLV-1 carriers accumulate in Southwest Japan mainly Kyushu, and tend to be found commonly in the portside regions. However, they are seen sporadically in other regions.
<<Diagnosis>>
ATL is usually diagnosed by,(1)anti-HTLV-I antibody is positive,(2)tumor cells are derived from T-cells,(3)characteristic clinical presentations, hemograms, and pathological images.
Compared to other leukemia or malignant lymphoma, ATL shows a marked tendency to infiltrate into the organs in the whole body, and especially this is associated with a much higher incidence of gastrointestinal tract lesions.
<<Pathology>>
Essentially this is T-cell type systemic malignant lymphoma, and shapes of lesions are various. Also compared to other leukemia or malignant lymphoma, it shows a marked tendency to infiltrate into the organs in the whole body.
Because other than various formation of tumors, helper T-cells which play a pivotal role in immunity are affected, as medical conditions progress, various opportunistic infections caused by low immunity are seen.
Because ATL shows diverse clinical features it can be divided into 4 subtypes such as acute, lymphoma, chronic, and smoldering type. As a stage of disease, it can be classified into acute and chronic type, or smoldering type. Also in acute type, typically the characteristics of leukemia are strong, and lymphadenopathy is not distinctive. On the other hand, however the characteristics of systemic malignant lymphoma are strong in lymphoma type, progression often can lead to leukemia.
<<Characteristics of gastrointestinal tract lesion>>
As characteristics of the gastrointestinal tract infiltration lesions of ALT, following items are listed (1)infiltration affects in a large segment and high degree,(2)this grows and develops frequently or diffuse-invasively,(3)various gross images are seen, and its tendency is strong in the stomach.
<<Characteristics of gastrointestinal tract lesion>>
In the cases which gastrointestinal tract infiltration occurs, as morphological characteristics, the mucosa with a granular appearance, erosions or ulcers, enlargement and disturbance of the mucosal folds, edemas, sucker-like protuberances, various size of nodules or submucosal tumor like protuberances and others are seen frequently. In addition, though it often show single gross image in the intestinal tract lesions, it tends to present various kinds of gross images in the stomach.