Skin nontumor
Dermal granulomatous and necrobiotic reaction patterns
Interstitial granulomatous dermatitis
Topic Completed: 1 June 2011
Minor changes: 22 July 2020
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PubMed Search: Interstitial granulomatous dermatitis with arthritis
Table of Contents
Definition / general | Case reports | Treatment | Clinical images | Microscopic (histologic) description | Microscopic (histologic) images | Positive stains | Differential diagnosis | Additional referencesCite this page: Hamodat M. Interstitial granulomatous dermatitis. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/skinnontumorinterstitialgranulomatous.html. Accessed March 2nd, 2021.
Definition / general
- Uncommon; first described in 1993
- Linear inflammatory indurations on lateral aspects of trunk (rope sign), also plaques or papules associated with systemic connective tissue disease
- Usually in women
- Arthritis is usually symmetric and involves fingers, wrists, elbows and shoulders
- Associated with positive rheumatoid factor (not always), autoantibodies and elevated erythrocyte sedimentation rate
Case reports
- 34 year old woman with SLE and a skin rash (Case #221)
- 54 year old woman with arthritis (Dermatol Online J 2009;15:22)
- Disease without rope sign (Hum Pathol 2004;35:892)
Treatment
- Systemic corticosteroids
- Dapson was useful in patients with rheumatoid papules
Clinical images
Images hosted on other servers:
Plaque on thigh
Microscopic (histologic) description
- Diffuse dense inflammatory infiltrate of histiocytes within reticular dermis, focal degenerated collagen and elastic fibers, palisading histiocytes
- Variable neutrophils, eosinophils, lymphocytes, mucin and vasculitis
- Less mucin than granuloma annulare
- Palisading of histiocytes and lymphocytes around a central zone of numerous neutrophils
Microscopic (histologic) images
Images hosted on other servers:
Superficial and deep perivascular and interstitial infiltrate of lymphocytes, eosinophils and histiocytes; histiocytes are scattered between collagen bundles and associated with mucin deposits
Positive stains
- Direct immunofluorescence (DIF) may demonstrate C3, IgM and fibrinogen in dermal blood vessels
Differential diagnosis
- Granulomatous drug reactions: vacuolar interface changes, often epidermotrophism of lymphocytes; resolves when drug is stopped
- Interstitial granuloma annulare: mid dermal necrobiotic collagen center surrounded by palisading histiocytes, with fibroblasts and lymphocytes; occasional foreign body giant cells, vasculitis, mucin; may need multiple sections to find necrobiotic collagen
- Necrotizing granuloma: may be due to infectious microorganism
- Rheumatoid dermatosis: extensive homogeneous necrobiosis with numerous giant cells and stromal fibrosis
Additional references
- Hum Pathol 2004;35:779 (editorial)
