Autoimmune Diseases
Donna M. Coffey, MD
Key Facts
Cytopathology
Rheumatoid arthritis effusions
Seen in a minority of patients (< 5%) with established rheumatoid disease
Have spindled, epithelioid, or multinucleated macrophages, lymphocytes, and neutrophils with acellular granular material in background
Systemic lupus erythematosus effusions
More common, seen in up to 50% of patients
Have nonspecific cytologic findings with lymphocytes, neutrophils, and lupus erythematosus cells (seen only in ˜ 27%)
Top Differential Diagnoses
Infections with necrotizing granulomas, trauma/infarct, metabolic diseases, or malignancies with nonspecific inflammation
 (A) Diff-Quik shows pleural effusion on a patient with systemic lupus erythematosus (LE). Note an LE cell with a large magenta intracytoplasmic inclusion that pushes the nucleus to the side  . (B) Pap stain shows an LE cell. A neutrophil contains a large homogeneous intracytoplasmic inclusion, which stains blue-green on Pap stain  . (C) Pap stain of a pleural effusion in a patient with rheumatoid arthritis contains few multinucleated giant cells and spindled histiocytes. (D) Pap stain shows a rheumatoid pleural effusion with irregular aggregates of granular material and macrophages  . |
