CD30(+) anaplastic large-cell lymphoma with aberrant expression of CD13: Case report and review of the literature

CD13 is commonly expressed in hematopoietic malignancies of myelomonocytic origin and has less commonly been described in lymphoid neoplasms, includin g acute lymphoblastic leukemia, B-cell lymphoproliferative disorders, and p lasma cell malignancies. Aberrant CD13 expression has rarely been described in KP-1 (CD68)-positive large-cell lymphomas. However, CD13 positivity has not previously been described in a case of CD30(+) (ALK-1(+)) anaplastic l arge-cell lymphoma of presumed null-cell origin without histiocytic differe ntiation. The purpose of this case report is to describe a CD30(+) anaplast ic large-cell lymphoma of presumed null-cell origin with aberrant expressio n of CD13. The case illustrates the unique usefulness of immunophenotypic a nd molecular techniques in establishing the correct diagnosis. The case was referred with a diagnosis of "rule out granulocytic sarcoma versus megakar yocytic malignancy" due to the morphology and a limited flow cytometric imm unophenotypic (FCI) panel that had been performed and revealed expression o f CD45, HLA-DR, and CD13. Subsequent morphologic review at our institution combined with an expanded FCI panel established the diagnosis. The differen tial diagnosis of a CD13(+) hematopoietic malignancy should include this en tity. The prognostic significance of this finding has yet to be determined. J. Clin. Lab. Anal. 14:299-304, 2000. (C) 2000 Wiley-Liss, Inc.