Frequent expression of CD99 in anaplastic large cell lymphoma: a clinicopathologic and immunohistochemical study of 160 cases.
Originally described as a diagnostically useful marker for Ewing sarcoma, CD99 immunoreactivity has also been documented in a variety of other tumors, including hematopoietic neoplasms. By using conventional paraffin immunoperoxidase staining and tissue microarrays, we retrospectively investigated CD99 expression in a series of 160 anaplastic large cell lymphoma (ALCL) cases. Of the 160 cases, 103 (64.4%) were positive for CD99. The distribution of CD99 positivity was similar for nodal (66/103 [64.1%]), extranodal, (21/32 [66%]), and primary cutaneous lesions (16/25 [64%]). CD99 expression was present in 96 (64.4%) of 149 of the common type, 4 (80%) of 5 of the small cell variant, and 3 (50%) of 6 of the lymphohistiocytic variant cases. CD99 expression was slightly more frequent in anaplastic large cell lymphoma kinase (ALK)+ cases compared with ALK- cases (43/54 [80%] vs 44/81 [54%]). With 2 exceptions, ALK+ ALCL was seen only in patients younger than 41 years. We conclude that CD99 is frequently expressed in ALCL, with a slightly increased frequency in the younger age ALK+ cases. Nodal and extranodal ALCL should be considered in the differential diagnosis when a CD99+ neoplasm is encountered.
Buxton
Daniel
D
Department of Pathology and Laboratory Medicine, Loma Linda University School of Medicine, Loma Linda, CA 92354, USA.
Bacchi
Carlos E
CE
Gualco
Gabriela
G
Weiss
Lawrence M
LM
Zuppan
Craig W
CW
Rowsell
Edward H
EH
Huang
Qin
Q
Wang
Jun
J
D000071443:12E7 Antigen; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000077548:Anaplastic Lymphoma Kinase; D015703:Antigens, CD / Q000096:biosynthesis*; D014408:Biomarkers, Tumor / Q000032:analysis*; D015815:Cell Adhesion Molecules / Q000096:biosynthesis*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007223:Infant; D017728:Lymphoma, Large-Cell, Anaplastic / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D020794:Receptor Protein-Tyrosine Kinases; D046888:Tissue Array Analysis
D000071443:12E7 Antigen; D015703:Antigens, CD; D014408:Biomarkers, Tumor; 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