Severe cytomegalovirus colitis with highly elevated sIL-2R mimicking aggressive transformation of adult T-cell lymphoma.

A smouldering adult T-cell leukaemia/lymphoma (ATLL) patient was admitted because of multiple erosions in the colon, which were infiltrated by a mixed population of lymphocytes. PET/CT demonstrated diffuse 18F-Fluorodeoxyglucose accumulation in the whole colon accompanied by multiple lymph node swelling. Histological examinations of lymph node suggested aggressive transformation to lymphoma type of ATLL. However, the general condition worsened with extremely elevated LDH, cytomegalovirus pp65 and sIL-2R after the administration of prednisolone. By contrast, subsequent administration of ganciclovir with tapered prednisolone ameliorated the laboratory findings. Differential diagnosis for aggressive ATLL and serious cytomegalovirus infection is needed.