Diffuse intermediate lymphocytic lymphoma. A clinicopathologic study and comparison with small lymphocytic lymphoma and diffuse small cleaved cell lymphoma

Controversy has recently arisen as to whether diffuse intermediate lymphocytic lymphoma (ILL) should be considered a low‐grade or an intermediate‐grade non‐Hodgkin's lymphoma for clinical purposes. Therefore, the authors performed a clinicopathologic study to determine the biologic course of diffuse ILL (40 cases) and compared it with small lymphocytic lymphoma (SLL; 51 cases) and diffuse small cleaved cell lymphoma (DSCCL; 14 cases). They found that patients with diffuse ILL having pseudofollicular proliferation centers (PC) had a significantly longer median survival (84 months) than those without PC (46.5 months; P = 0.03). The median survival of patients with SLL was 72 months, whereas those with DSCCL had a median survival of only 18 months. Based on these findings, the authors conclude that diffuse ILL with PC should be included in the low‐grade category of SLL for clinical purposes, whereas diffuse ILL without PC (true diffuse ILL) should be considered an intermediate‐grade non‐Hodgkin's lymphoma. True diffuse ILL is similar to centrocytic lymphoma in the Kiel classification and should be accorded a similar status in a modified Working Formulation.