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The malignant cells stain positive for ALK1 (anaplastic large cell kinase) by immunohistochemistry. Note that the staining pattern in this case is exclusively cytoplasmic, with the nuclei apparently devoid of ALK1. ALK1 staining is relatively specific for ALCL, as the protein is not known to be expressed in any other hematopoietic malignancies aside from a rare form of plamacytoid diffuse large B-cell lymphoma expressing cytoplasmic IgA. ALK1 expression is the most important prognostic factor in ALCL, and these tumors have an average 80% 5-year survival rate, as compared to 40% for ALK1-negative ALCL.
Anaplastic Large Cell Lymphoma Involving the Bone Marrow - 7.
#00003318
Author: John Lazarchick; Gregor Krings;
Category: Lymphoma: Mature T and NK cell lymphoproliferations > Mature T-cell Lymphomas > Anaplastic Large Cell Lymphoma, ALK positive
Published Date: 10/31/2011
Category: Lymphoma: Mature T and NK cell lymphoproliferations > Mature T-cell Lymphomas > Anaplastic Large Cell Lymphoma, ALK positive
Published Date: 10/31/2011
The malignant cells stain positive for ALK1 (anaplastic large cell kinase) by immunohistochemistry. Note that the staining pattern in this case is exclusively cytoplasmic, with the nuclei apparently devoid of ALK1. ALK1 staining is relatively specific for ALCL, as the protein is not known to be expressed in any other hematopoietic malignancies aside from a rare form of plamacytoid diffuse large B-cell lymphoma expressing cytoplasmic IgA. ALK1 expression is the most important prognostic factor in ALCL, and these tumors have an average 80% 5-year survival rate, as compared to 40% for ALK1-negative ALCL.
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