Clinicopathologic Features of CD23-Positive Nodal Marginal Zone Lymphomas

Abstract Objectives: To identify and describe the clinicopathologic features characterizing a set of patients with nodal marginal zone lymphoma (N-MZL) positive for expression of CD23 and to contrast findings against those of a cohort of patients with CD23-negative N-MZL. Methods: Cases of N-MZL diagnosed over a 20-year interval were identified from the medical record and allocated to two cohorts based on immunophenotypic expression of CD23. Clinical, morphologic, immunophenotypic and cytogenetic data were retrospectively reviewed. Results: Twenty-six cases with histological and immunophenotypic findings typical of N-MZL were identified, 12 of which expressed CD23 by flow cytometry or immunohistochemistry. In the CD23-positive N-MZL cohort, only 2/12 (17%) of patients demonstrated multicompartment lymphadenopathy and another 3/12 (25%) demonstrated bone marrow involvement, with an Ann Arbor disease stage IV. In the CD23-negative cohort, 8/14 (57%) patients presented with multicompartment lymphadenopathy and an additional 6/14 (43%) demonstrated bone marrow involvement, with an Ann Arbor disease stage IV. The average follow-up period for all patients (CD23-positive and CD23-negative cohorts) was 6.7 years (range: 1-17; IQR: 10). In the CD23-positive disease cohort, treatment and follow-up data were recorded for 10/12 (83%) patients. Three patients were followed without intervention, one of which transformed to an aggressive lymphoma. This patient was treated with a series of rituximab-based chemotherapies and remains well two years post stem cell transplant. One patient was surgically managed with adjuvant radiation and remains well with no evidence of disease. Six others were treated with various rituximab-based chemotherapy regimens. Two died secondary to sequalae related to progression of their disease. The others remain alive and well with no evidence of active disease. In the CD23-negative disease cohort, treatment and follow-up data were recorded for 13/14 (93%) patients. For seven patients in this cohort followed by observation only, five were alive and well at last follow-up. Two were deceased due to unrelated causes. For those otherwise treated, there was only a single fatality due to progression of disease. Comparing the two cohorts, those with CD23-positive disease were significantly more likely to present with a lower Ann Arbor stage (p=0.0155) and FLIPI score (p=0.0086). However, neither 5-year (p=0.6908) nor overall survival (p=0.5956) were si