Expression of bcl-2 in CHL is a useful, independent prognostic marker and can be used in association with clinical parameters to identify newly diagnosed patients with a good, intermediate, or poor prognosis.

ZAP-70 is a tyrosine kinase expressed in normal T cells and NK cells. Expression of ZAP-70 has been associated with poor prognosis in B-cell chronic lymphocytic leukemia and might be a surrogate marker for immunoglobin heavy chain (IGH) mutational status in that disease. Little is known about ZAP-70 expression in other hematologic malignant neoplasms. We examined 446 specimens representing a range of hematopoietic malignant neoplasms for ZAP-70 expression by immunohistochemical analysis. As expected, most T cell-lineage disorders and a subset of small lymphocytic lymphomas were positive. IGH mutational status corresponded to ZAP-70 expression in a small subset of small lymphocytic lymphoma cases subjected to sequence analysis. Of note, however, ZAP-70 was expressed in a minority of other types of B-cell lymphomas, including precursor B-cell acute lymphoblastic leukemia, diffuse large B-cell lymphoma, mantle cell lymphoma, and very rare cases of classic Hodgkin lymphoma. Immunohistochemical analysis represents an alternative method for assessing ZAP-70 expression and reveals that other B-cell malignant neoplasms express ZAP-70.

Classical Hodgkin lymphoma (cHL) and mediastinal (thymic) large B-cell lymphoma (MLBL) have clinical, histopathologic, and molecular genetic similarities. MAL, a gene that encodes a protein associated with lipid rafts in T and epithelial cells, is overexpressed in a majority of MLBLs and has been reported in a minority of cHLs. To study the clinical significance of MAL in cHL, we immunostained 86 cases; 16 cHLs (19%) expressed MAL. Expression correlated with nodular sclerosis subtype, and within this subtype, with grade 2 histology. Univariable analysis revealed association of age of 45 years or older, MAL expression, and an International Prognostic Score of more than 2 with worse failure-free survival. Age of 45 years or older, MAL expression, and stage III or IV were associated with worse overall survival (OS). Cox proportional hazards modeling showed age (P = .04 and P = .03, respectively) and MAL expression (P = .03 and P = .01, respectively) as independent predictors of time to failure-free survival and OS. Stage showed borderline significance in OS (P = .08). MAL expression seems to identify a subset of cHL with an adverse outcome and provides additional evidence for a link between cHL and MLBL.

Classical Hodgkin lymphoma (cHL) and mediastinal (thymic) large B-cell lymphoma (MLBL) have clinical, histopathologic, and molecular genetic similarities. MAL, a gene that encodes a protein associated with lipid rafts in T and epithelial cells, is overexpressed in a majority of MLBLs and has been reported in a minority of cHLs. To study the clinical significance of MAL in cHL, we immunostained 86 cases; 16 cHLs (19%) expressed MAL. Expression correlated with nodular sclerosis subtype, and within this subtype, with grade 2 histology. Univariable analysis revealed association of age of 45 years or older, MAL expression, and an International Prognostic Score of more than 2 with worse failure-free survival. Age of 45 years or older, MAL expression, and stage III or IV were associated with worse overall survival (OS). Cox proportional hazards modeling showed age (P = .04 and P = .03, respectively) and MAL expression (P = .03 and P = .01, respectively) as independent predictors of time to failure-free survival and OS. Stage showed borderline significance in OS (P = .08). MAL expression seems to identify a subset of cHL with an adverse outcome and provides additional evidence for a link between cHL and MLBL.

ZAP-70 is a tyrosine kinase expressed in normal T cells and NK cells. Expression of ZAP-70 has been associated with poor prognosis in B-cell chronic lymphocytic leukemia and might be a surrogate marker for immunoglobin heavy chain (IGH) mutational status in that disease. Little is known about ZAP-70 expression in other hematologic malignant neoplasms. We examined 446 specimens representing a range of hematopoietic malignant neoplasms for ZAP-70 expression by immunohistochemical analysis. As expected, most T cell-lineage disorders and a subset of small lymphocytic lymphomas were positive. IGH mutational status corresponded to ZAP-70 expression in a small subset of small lymphocytic lymphoma cases subjected to sequence analysis. Of note, however, ZAP-70 was expressed in a minority of other types of B-cell lymphomas, including precursor B-cell acute lymphoblastic leukemia, diffuse large B-cell lymphoma, mantle cell lymphoma, and very rare cases of classic Hodgkin lymphoma. Immunohistochemical analysis represents an alternative method for assessing ZAP-70 expression and reveals that other B-cell malignant neoplasms express ZAP-70.