A 42-year-old woman from Delhi presents with a 6-month history of symmetric polyarthritis affecting her wrists, knees, and small joints of the hands. Morning stiffness lasts 2 hours. Examination reveals warm, tender swelling of the PIP and MCP joints bilaterally. Laboratory investigations show: Hb 10.2 g/dL, ESR 68 mm/hr, CRP 45 mg/L, RF 280 IU/mL (positive), anti-CCP antibodies 95 U/mL (positive). X-ray of hands shows periarticular osteopenia and early marginal erosions. Histology of a synovial biopsy specimen is most likely to show which of the following?