MAL Is Expressed in a Subset of Hodgkin Lymphoma and Identifies a Population of Patients With Poor Prognosis

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.