Mediastinal Gray Zone Lymphoma with Features Intermediate between Classical Hodgkin Lymphoma and Primary Mediastinal B-Cell Lymphoma

Abstract

Background: Mediastinal gray zone lymphoma (MGZL) shares clinical characteristics with primary mediastinal B-cell lymphoma (PMBCL) and nodular sclerosing Hodgkin lymphoma (NSHL). However, MGZL is extremely rare, and an appropriate treatment for it has not yet been established.

Methods: We retrospectively analyzed 8 patients who were treated with systemic chemotherapy for MGZL between 2007 and 2014.

Results: The patients with MGZL were predominantly young and male (median age 26 years), and 62.5% of patients had bulky disease. The overall response rate (ORR) and complete remission (CR) rate were both 75% (6/8) for all treated patients The median overall survival (OS) and progression-free survival (PFS) was 40.7 and 3.9 months, respectively. Most responders (4/6, 66.7%) were treated with R-CHOP (rituximab + cyclophosphamide, hydroxydaunorubicin, Oncovin and prednisolone) as the frontline therapy. The CR rate of patients who received R-CHOP and those who did not was 100% (4/4) and 50% (2/4), respectively. Particularly striking was the finding that the median PFS of patients who received R-CHOP frontline chemotherapy was 11.4 months, which was superior to the median PFS of patients who did not receive R-CHOP.

Conclusions: Of the 8 patients with MGZL who were treated with systemic chemotherapy, superior treatment responses were observed in patients who received R-CHOP as the frontline therapy.