Lack of expression of TUBB3 characterizes both BCL2-positive and BCL2-negative follicular lymphoma.
Follicular lymphoma is characterized by aberrant BCL2 expression, a feature that is exploited for diagnostic purposes. However, a certain percentage of follicular lymphomas might be BCL2-negative by immunohistochemistry, increasing the difficulties in differentiating them from follicular hyperplasia. The expression of TUBB3 has been recently reported as negative in a small series of follicular lymphomas. We have therefore tested a larger series, including 61 BCL2-positive and 25 BCL2-negative cases, and compared them with 61 reactive lymphoid tissues. First, a subjective score of TUBB3 staining was applied, showing that it was consistently positive in reactive germinal centers, while most follicular lymphomas were negative; in fact, only 10/61 (16%) BCL2-positive and 1/25 (4%) BCL2-negative cases showed a positive staining for TUBB3, while 58/61 (95%) of tissues with follicular hyperplasia were positive. The application of a standardized scoring system to a large number of follicles, based on virtual slides, demonstrated that reactive lymphoid tissues had a significantly higher number of TUBB3-positive follicles both compared with BCL2-positive cases and to BCL2-negative cases. Our data support the use of TUBB3 staining in differentiating follicular lymphoma, including BCL2-negative cases, from follicular hyperplasia.
Department of Pathology and Diagnostics, Anatomia Patologica, University of Verona, Verona, Italy.
Alberto
A
Zamò
Department of Pathology and Diagnostics, Anatomia Patologica, University of Verona, Verona, Italy.
Francesco
F
Erdini
Department of Life and Reproduction Sciences, University of Verona, Verona, Italy.
Giovanni
G
Malerba
Department of Pathology and Diagnostics, Anatomia Patologica, University of Verona, Verona, Italy.
Marco
M
Chilosi
D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis*; D003937:Diagnosis, Differential; D005260:Female; D018858:Germinal Center / Q000473:pathology; D006801:Humans; D006965:Hyperplasia / Q000175:diagnosis; D007150:Immunohistochemistry; D008224:Lymphoma, Follicular / Q000175:diagnosis* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000096:biosynthesis; D012189:Retrospective Studies; D014404:Tubulin / Q000096:biosynthesis*
D014408:Biomarkers, Tumor; D019253:Proto-Oncogene Proteins c-bcl-2; C498585:TUBB3 protein, human; D014404:Tubulin