Centroblastic and Centroblastic/Centrocytic Lymphoma Associated with a Prominent Epithelioid Granulomatous Response: a Clinicopathologic Study of 50 Cases

Abstract

A minority of centroblastic and centroblastic/centrocytic cell lymphomas are accompanied by a prominent epithelioid cell response and were suggested to be a distinct variant of B-cell lymphoma of germinal center cell origin. To confirm the clinicopathologic significance of these mainly large B-cell lymphomas with an epithelioid cell response (LBCL-ER), we reviewed 50 patients with LBCL-ER and compared the results with those of 167 other diffuse large B-cell lymphomas (DLBCL) and 94 follicular lymphomas (FL) without epithelioid response. The patients with LBCL-ER showed a higher age distribution (median 71, P = .03), a female predominance (M:F = 18:32, P = .001) and less frequent involvement of extranodal sites >1 (P = .004) compared with those with DLBCL, and presented with a bulky mass of the affected lymph nodes in 54% of cases. They were also older (P = .0006) and more associated with the aggressive clinical factors such as serum LDH level and International Prognostic Index score than those with FL. Histologically, nine cases (18%) partially showed a follicular growth pattern, and the others (82%) were occupied by a diffuse growth pattern. The epithelioid cells were accumulated in large demarcated masses, partially imparting a lymphoepithelioid (Lennert) lymphoma-like appearance to some portions of the lesions in every case. Immunohistochemically, LBCR-ER was positive for CD20 in every case, CD10 in 43% of the cases, and BCL-2 in 56%. None of the tumor cells in the 40 cases tested expressed CD5 antigen. Immunostaining also often highlighted the remnants of the follicular dendritic cell network. The BCL-2 gene rearrangement was detected in only 19% of the cases examined. The survival curve of the cases of LBCL-ER was almost identical with that of DLBCL and was significantly inferior to that of FL. The centroblastic and centroblastic/centrocytic lymphoma with an epithelioid cell response may be regarded as the morphologic variant of DLBCL preferentially arising in the aged population and reflecting the disease progression of FL.