The final products of digestion are absorbed through the intestinal epithelial cells.Malabsorption constitutes the pathological interference with the normal physiological sequence of digestion (intraluminal process), absorption (mucosal process) and transport (postmucosal events) of nutrients.Intestinal malabsorption can be due to:
Congenital or acquired reduction in absorptive surface
Defects of ion transport
Defects of specific hydrolysis
Impaired enterohepatic circulation
Mucosal damage (enteropathy)
Pancreatic insufficiency

Diagnosis
There is no single, specific test for malabsorption. As for most medical conditions, investigation is guided by symptoms and signs. A range of different conditions can produce malabsorption and it is necessary to look for each of these specifically. Many tests have been advocated, and some, such as tests for pancreatic function are complex, vary between centers and have not been widely adopted. However, better tests have become available with greater ease of use, better sensitivity and specificity for the causative conditions. Tests are also needed to detect the systemic effects of deficiency of the malabsorbed nutrients (such as anaemia with vitamin B12 malabsorption). Classification
Some prefer to classify malabsorption clinically into three basic categories:
selective, as seen in lactose malabsorption. partial, as observed in abetalipoproteinaemia. total, as in exceptional cases of coeliac disease. Blood tests
Routine blood tests may reveal anaemia, high CRP or low albumin; which shows a high correlation for the presence of an organic disease. In this setting, microcytic anaemia usually implies iron deficiency and macrocytosis can be caused by impaired folic acid or B12 absorption or both. Low cholesterol or triglyceride may give a clue toward fat malabsorption.
T-cell acute lymphoblastic leukemia may refer to:

T-lymphoblastic leukemia/lymphoma, a form of lymphoid leukemia and lymphoma
Adult T-cell leukemia/lymphoma, a rare cancer of the immune systems own T-cells