A case report of mantle zone lymphoma progressing into follicular lymphoma.

The authors report a case of mantle zone lymphoma (MZL) progressing into follicular lymphoma (FL) with macroglobulinemia (IgM, lambda). At a first lymph node biopsy, a diagnosis of MZL was made on the basis of the presence of vague neoplastic nodules, consisting of small lymphoid cells and small cleaved cells. At a second lymph node biopsy, nodules of follicular lymphoma were observed in the central zones of the vague neoplastic nodules. At a third biopsy, the central zones were found to expand, revealing FL dominant pattern. The progress of FL from MZL also was suggested by sIg, AIPase, anti-CALLA (common acute lymphoblastic leukemia antigen) antibody, and anti-DRC (dendritic reticulum cell) antibody findings. Consequently, this is suggested to be a neoplasm of B-lymphocytes differentiating from small lymphocytes in the primary follicle or the mantle zone of secondary follicle into germinal center cells. The anti-DRC antibody findings suggest the neoplastic cells of FL induce DRC as the neoplastic stroma.