Burkitt's lymphoma in a patient with adenosine deaminase deficiency-severe combined immunodeficiency treated with polyethylene glycol-adenosine deaminase.

We describe a patient with severe combined immunodeficiency because of aberrations in adenosine deaminase (ADA) who despite adequate replacement with polyethylene glycol-linked ADA (PEG-ADA) for 13 years developed Burkitt's lymphoma. Although treatment corrected the metabolic abnormalities caused by ADA deficiency, it failed to fully restore cellular immunity.