Classical Hodgkin lymphoma, lymphocyte depleted type: Clinicopathological analysis and prognostic comparison with other types of classical Hodgkin lymphoma

The lymphocyte-depleted type (LD) is a morphological subtype of classical Hodgkin lymphoma (CHL), but its rarity and heterogeneous morphological character makes a definite clinicopathological identification difficult. To characterize this disease, LD cases were compared with other types of CHL. From 1982 to 2006, we collected 310 CHL cases. Among them, 29 cases were diagnosed as LD. We could additionally analyze clinical data of 157 CHL cases (including 28 LD cases) and the immunophenotype of 150 CHL cases (including 28 LD cases). We compared clinicopathological data between LD cases and other types of CHL cases and determined prognostic factors by univariate and multivariate analysis. LD showed a more progressive disease stage (stage 3/4, 64%) than other types of CHL (stage 3/4, 30%; P < 0.001), more frequent B symptoms (89% vs. 40%; P < 0.001) and extranodal invasion (50% vs. 11%; P < 0.001), older age (median: 66 vs. 33; P < 0.001), higher serum soluble interleukin 2 receptor levels (median: 8240 U/ml vs. 1705 U/ml; P < 0.001), and much poorer prognosis regardless of the international prognostic score (IPS) (five-year overall survival: 29% vs. 86%; P < 0.001). The morphological subtype of LD represented an independent prognostic factor as did age and IPS by multivariate analysis. Immunohistochemistry showed that the characteristics of Hodgkin and Reed–Sternberg (HRS) cells of LD are basically not different from those of other types of CHL in terms of CD30, CD15, and chemokine receptors, except for high-level EB-virus infection (72% vs. 41%; P = 0.002). LD should be distinguished from other types of classical Hodgkin lymphoma because of its definitive clinicopathological characters.