Fig. 2From: Recognizing puzzling PD1 + infiltrates in marginal zone lymphoma by integrating clonal and mutational findings: pitfalls in both nodal and transformed splenic casesMorphologic and immunophenotypic findings of lymphoma in Case 2. Follicles were regressed, and the B-cell population was reduced (A) as also shown by CD20 immunostaining (B); extensive accumulation of PD-1-positive cells was observed in both centralized and peripheralized patterns around the follicles (C); an irregularly enveloped follicular dendritic cell meshwork is revealed by CD21 (D); rare small positive lymphoid cells were also noted by in situ hybridization with Epstein–Barr virus-encoded small RNAs (E)Back to article page