Immunoreactivity of CD99 in non-Hodgkin's lymphoma: unexpected frequent expression in ALK-positive anaplastic large cell lymphoma.
To verify the spectrum of CD99-expressing lymphoid malignancy, an immunohistochemical study for CD99 was carried out in 182 cases of non-Hodgkin's lymphoma, including 21 lymphoblastic lymphomas, 11 small lymphocytic lymphomas, 9 mantle cell lymphomas, 12 follicular lymphomas, 37 diffuse large B cell lymphomas, 18 Burkitt's lymphomas, 28 NK/T-cell lymphomas, 8 angioimmunoblastic T-cell lymphomas, 23 peripheral T-cell lymphomas, unspecified, and 15 systemic anaplastic large cell lymphomas. CD99 was positive in all T-lymphoblastic lymphomas and in 60% of B-lymphoblastic lymphomas. Majority of T and NK cell lymphomas were negative for CD99, except anaplastic large cell lymphomas (ALCLs). Eight of 15 cases (54%) of ALCLs reacted with anti CD99 antibody. Seven of 10 (70%) ALK positive ALCLs expressed CD99, whereas only 1 of 5 (20%) ALK negative ALCLs were positive. Of the mature B-cell lymphomas, 5.4% (2/37) of diffuse large B cell lymphomas and 11.1% (2/18) of Burkitt's lymphomas expressed CD99. In conclusion, CD99 is infrequently expressed in mature B and T cell lymphomas, except ALK-positive ALCL. High expression of CD99 in ALK-positive ALCL is unexpected finding and its biologic and clinical significances have yet to be clarified.
Sung
Chang Ohk
CO
Department of Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
Ko
Young H
YH
Park
Sanghui
S
Kim
Kihyun
K
Kim
Wonseog
W
D000071443:12E7 Antigen; D000077548:Anaplastic Lymphoma Kinase; D015703:Antigens, CD / Q000378:metabolism*; D015153:Blotting, Western; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D016403:Lymphoma, Large B-Cell, Diffuse / Q000201:enzymology / Q000276:immunology* / Q000473:pathology; D008228:Lymphoma, Non-Hodgkin / Q000201:enzymology / Q000276:immunology* / Q000473:pathology; D011505:Protein-Tyrosine Kinases / Q000276:immunology / Q000378:metabolism*; D020794:Receptor Protein-Tyrosine Kinases
D000071443:12E7 Antigen; D015703:Antigens, CD; C061828:CD99 protein, human; D015815:Cell Adhesion Molecules; C000626173:ALK protein, human; D000077548:Anaplastic Lymphoma Kinase; D011505:Protein-Tyrosine Kinases; D020794:Receptor Protein-Tyrosine Kinases