RÉSUMÉ
<p><b>OBJECTIVE</b>To explore the significance of C4d deposition in follicular lymphoma (FL).</p><p><b>METHODS</b>The deposition of C4d was detected in samples from 133 cases of lymphoma by immunohistochemistry and FL was studied by the double stainings of CD35/C4d, CD21/C4d and Bcl-2/C4d,respectively.</p><p><b>RESULTS</b>Among the 26 FL tissues, irregular C4d deposition was seen in 19 tumor tissues. Double staining for CD35, CD21 or Bcl-2 showed the C4d deposition was around the follicular dendritic cells (FDC). There was no significant difference between the positive rate of C4d and the degree of lymphoma. No deposition was found in the diffuse areas of FL and other type lymphomas.</p><p><b>CONCLUSION</b>C4d deposition around the follicular dendritic cell in the neoplastic follicles is a specific indicator of follicular lymphoma.</p>