CD20-negative DLBCL transformation after rituximab treatment in follicular lymphoma: a new case report and review of the literature

T Alvaro-Naranjo, J Jaén-Martínez, J Gumá-Padró, R Bosch-Príncep, M T Salvadó-Usach
Annals of Hematology 2003, 82 (9): 585-8
Rituximab is a monoclonal antibody against the CD20 molecule which is used to treat B-cell lymphomas. In 60% of low-grade B lymphomas in which rituximab was effective at first, there was no clinical response in a second treatment and a few cases of follicular lymphomas (FL) with transformation to diffuse large B-cell lymphoma (DLBCL) have been reported. We describe a new case and hypothesize about the mechanisms of transformation: a 52-year-old man, in follow-up during 8 years for FL, who after rituximab treatment and complete remission of FL showed progressive disease involving the liver and duodenal mucosa. Immunohistochemical and molecular studies were performed on paraffin-embedded tissue samples of lymph nodes, the small intestine, and liver tumors. After rituximab treatment, biopsies of a liver lesion and the small bowel both showed CD20-negative large B-cell lymphoma. Molecular study of the initial and relapse specimens shows a CDR2 IgH rearrangement with the same height and t14;18 (MBR). The rapid relapse with the same rearrangement of IgH seems to support the interpretation that the change of grade of lymphoma and loss of CD20 expression occurred before rituximab treatment. The existence of a varying proportion of a CD20-negative cell population in every B-cell lymphoma which does not respond to rituximab should therefore be considered. The reduction of CD20 expression could be a resistance mechanism to rituximab retreatment in DLBCL as a consequence of the progression of low-grade B-cell non-Hodgkin's lymphoma (B-NHL). It is necessary to perform new biopsies to evaluate CD20 expression in relapse or the progression of B-cell lymphoma after rituximab treatment.

Full Text Links

Find Full Text Links for this Article


You are not logged in. Sign Up or Log In to join the discussion.

Trending Papers

Remove bar
Read by QxMD icon Read

Save your favorite articles in one place with a free QxMD account.


Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"