Hodgkin-like lymphoma, simulating anaplastic large cell lymphoma in the patient after renal transplantation--unusual case report and literature review.

UNLABELLED

We report the atypical case of posttransplant lymphoproliferative disorder (PTLD) diagnosed in 55-year men 9 years after renal transplantation. It was evaluated only by bone marrow biopsy, which showed its total involvement with malignant lymphoma. It was composed of two populations of lymphoid cells: large RS-like cells and small to medium ones, with slightly angular nuclei without visible nucleoli. Both cellpopulations did not show positive reaction for typical B cell markers (CD20, CD79a). Large RS-like cells were positive with CD30 and EBV-LMP. However, negative reaction with CD15 and positive reactions with UCHL1 and EMA were not consistent with classical type of Hodgkin lymphoma. Morphological picture and immunophenotype had suggested anaplastic T cell lymphoma. Because of negative reaction with ALK1, initial diagnosis was ALCL ALK-negative. Then, additional stains with BOB1 and Oct2 were performed, which were positive. Taking it into account the diagnosis was changed; finally Hodgkin-like B lymphoma was diagnosed. The patient was treated with CHOP regimen with good response. 5 years after primary diagnose of PTLD he is steel free of disease.

CONCLUSIONS

1. Apart from typical forms of PTLD, one may expect cases with nonspecific morphological picture and phenotype. 2. Negative reactions with typical immunohistochemical markers for lymphocytes of B cell line do not exclude the possibility of B-cell proliferation.