RESUMEN
<p><b>OBJECTIVE</b>To study the expression of FHIT protein and its potential application in diagnosing classic Hodgkin lymphoma.</p><p><b>METHODS</b>Immunohistochemical study using EnVision method for FHIT tumor suppressor protein, hematopoietic stem cell markers CD133/AC133 and CD34, B-cell marker CD20, T-cell marker CD3 and oncoprotein c-erbB2 was performed on 33 cases of classic Hodgkin lymphoma.</p><p><b>RESULTS</b>Thirty-three of the Hodgkin lymphoma cases (90.9%) expressed FHIT protein. The antigen was mainly located in the cytoplasm, nucleus and membrane of classic Reed-Sternberg and Reed-Sternberg-like cells. Normal B and T lymphocytes, as well as their malignant counterparts, were negative for FHIT protein; whereas monocytes, histiocytes and dendritic cells were positive. All the cases studied were negative for CD133/AC133, CD34, CD3 and c-erbB-2. Two of the 33 cases showed positive staining for CD20 in some of the Reed-Sternberg cells.</p><p><b>CONCLUSION</b>The expression of FHIT protein can be used as a useful adjunct in diagnosing classic Hodgkin lymphoma.</p>