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

Abstract

CD13 is commonly expressed in hematopoietic malignancies of myelomonocytic origin and has less commonly been described in lymphoid neoplasms, including acute lymphoblastic leukemia, B-cell lymphoproliferative disorders, and plasma 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 large-cell lymphoma of presumed null-cell origin without histiocytic differentiation. The purpose of this case report is to describe a CD30+ anaplastic large-cell lymphoma of presumed null-cell origin with aberrant expression of CD13. The case illustrates the unique usefulness of immunophenotypic and molecular techniques in establishing the correct diagnosis. The case was referred with a diagnosis of "rule out granulocytic sarcoma versus megakaryocytic malignancy" due to the morphology and a limited flow cytometric immunophenotypic (FCI) panel that had been performed and revealed expression of CD45, HLA-DR, and CD13. Subsequent morphologic review at our institution combined with an expanded FCI panel established the diagnosis. The differential diagnosis of a CD13+ hematopoietic malignancy should include this entity. The prognostic significance of this finding has yet to be determined.