07 March 2026
: Case report 
Cryoglobulinemia Type II: Sustained Remission After B-Cell–Directed Therapy
Challenging differential diagnosis, Unusual or unexpected effect of treatment, Rare disease
Sara Giæver Suul
E 1*, Ann Kristin Kvam E 1, Malu Lian Hestdalen E 1,2, Ulla Randen BD 3, Øyvind Midtvedt E 4, Geir E. Tjønnfjord ABDE 1,2
DOI: 10.12659/AJCR.950857
Am J Case Rep 2026; 27:e950857
Figure 1 Bone marrow histology of Case 1. The bone marrow trephine biopsy shows intraparenchymatous nodular and diffuse lymphoid infiltration (A, HE, 20×). Immunoperoxidase staining for CD20 highlights the B-cell infiltration (B, 20×). Scarce IgM+ plasma cells are found in the lymphoid nodules and diffusely within the parenchyma. The lymphoid cells express membranous IgM and plasma cells express cytoplasmic IgM (C, anti-IgM peroxidase staining, 40×).