Histology USMLE Step 1 Practice Question
A 42-year-old woman with a 5-year history of rheumatoid arthritis presents to clinic with complaints of bilateral knee pain, swelling, and morning stiffness lasting 2 hours. Vitals are stable. Laboratory studies show ESR 48 mm/hr and RF positive. Arthrocentesis yields turbid synovial fluid with WBC 8,500/μL (92% neutrophils, 8% lymphocytes) and no crystals. Synovial membrane biopsy is performed to evaluate for disease progression. Microscopic examination reveals hyperplasia of the innermost cell layer lining the joint space, with prominent immune cell infiltration in the deeper subsynovial tissue. Which of the following cell types normally forms the synovial lining layer that is hyperplastic in this patient?
Answer choices
- AStratified squamous epithelial cells
- BSimple columnar epithelial cells
- CType A (macrophage-like) and Type B (fibroblast-like) synovial cellsCorrect answer
- DFibroblasts and myofibroblasts
- EVascular endothelial cells and pericytes
- FChondrocytes and synovial matrix proteins
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