Skin nontumor
Dermal granulomatous and necrobiotic reaction patterns
Rheumatoid / rheumatic nodules
Topic Completed: 1 August 2011
Minor changes: 16 June 2021
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PubMed Search: Rheumatoid / rheumatic nodules "loattrfree full text"[sb]
Table of Contents
Definition / general | Microscopic (histologic) description | Microscopic (histologic) images | Differential diagnosisCite this page: Hamodat M. Rheumatoid / rheumatic nodules. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/skinnontumorrheumatoidnodules.html. Accessed September 21st, 2021.
Definition / general
- Associated with adult and juvenile rheumatoid arthritis and rheumatic fever, in extensor elbow and other joints
- Usually subcutis
- Large, firm, asymptomatic, dome-shaped masses; may be painful
- Subcutaneous lesions develop at sites of trauma or at pressure points
- May involve abdominal wall and heart
Microscopic (histologic) description
- Typically in subcutaneous fat or soft tissue, although may extend to deep reticular dermis
- Note that granuloma annulare and necrobiosis lipodica have more superficial locations
- Fibrin deposition and necrobiosis is often seen in center of nodule surrounded by well developed palisading of histiocytes, vascular granulation tissue, lymphocytes, plasma cells, eosinophils, variable giant cells, fibrosis in older lesions, occasional giant cells
- No asteroid inclusions
- Occasionally leukocytoclastic vasculitis
Microscopic (histologic) images
Contributed by Hillary Rose Elwood, M.D.
Subcutaneous necrobiosis and fibrinoid degeneration with palisaded histiocytic inflammation
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Rheumatoid nodule - subcutis
Differential diagnosis
- Deep granuloma annulare, which tends to have more mucin deposition and less fibrin
- Epitheloid sarcoma
