Waldeyer's ring marginal zone B cell lymphoma: are the clinical and prognostic features nodal or extranodal? A study by the Consortium for Improving Survival of Lymphoma (CISL)

Abstract

There has been controversy surrounding Waldeyer's ring (WR), especially focused on the question of whether it should be regarded as a nodal or an extranodal site. We conducted retrospective analyses of marginal zone B cell lymphomas involving WR (WR-MZLs) to observe their clinical features and prognosis, with specific regard to the nodal-or-extranodal question. A total of 52 patients with histological diagnosis of WR-MZL were retrospectively analyzed. The most common involvement site was the tonsil (40.4 %). Ann Arbor stage III/VI disease was present in 48.1 % (25 of 52). The response rate of the 27 stage I/II patients was 88.9 %, with 21 complete remissions and three partial remissions. The median time to progression (TTP) was 3.7 years (95 % CI 2.5-4.9 years). The estimated 5-year TTP and overall survival rates were 39.4 and 90.5 %, respectively. In a comparison with the historical data regarding extra-WR MALT lymphoma and nodal MZL (N-MZL), MALT lymphoma showed better TTP results than did WR-MZL and N-MZL (P < 0.001).