Skin-nontumor / Clinical dermatology
Other dermatoses
Granuloma annulare

Author: Mowafak Hamodat, M.D., MB.CH.B, MSc., FRCPC (see Authors page)

Revised: 28 June 2016, last major update July 2011

Copyright: (c) 2002-2016, PathologyOutlines.com, Inc.

PubMed Search: Granuloma annulare [title] skin

Definition / General
  • Benign self-limited dermatosis characterized by raised annular lesions
Clinical Features
  • One or several papules, skin colored, red or violaceous, which form 1 - 5 cm annular or arcuate lesions
  • Self-limited, asymptomatic disorder of dorsum of hands and legs, occasionally generalized
  • Associated with morphea, chronic hepatitis C infection, autoimmune thyroiditis, secondary hyperparathyroidism, Plummer’s disease, myelodysplastic syndrome, metastatic carcinoma
  • Rarely associated with diabetes and disseminated
  • Some cases are persistent
  • 50% resolve within 2 years
  • May regress spontaneously after biopsy
  • May recurred seasonally in sun exposed areas

  • Pseudorheumatoid nodules: also called giant granuloma annulare; large, isolated, and deep necrobiotic collagen granulomas in extremities or occupate of children, may be limited to penis; not associated with rheumatoid or rheumatic disease; may affect siblings
Case Reports
Clinical Images

Images hosted on PathOut servers:

Breast skin, courtesy of Mark R. Wick, M.D.


Images hosted on other servers:

Erythematous to violaceous indurated papules

Micro Description
  • Mid dermal necrobiotic collagen center surrounded by palisading histiocytes, as well as fibroblasts and lymphocytes
  • Occasional foreign body giant cells, vasculitis and mucin
  • May need multiple sections to find necrobiotic collagen
Micro Images

Images hosted on PathOut servers:

Breast, courtesy of Mark R. Wick, M.D.


Images hosted on other servers:

H&E

H&E (left), Alcian Blue pH 2.5 (right)

Interstitial pattern

Positive Stains
Negative Stains
Electron Microscopy Description
  • Degenerated elastic fibers
Differential Diagnosis
  • Rheumatoid arthritis and rheumatic fever nodules: different clinical presentation
  • Annular elastolytic giant cell granuloma: histiocytes and foreign body giant cells engulfing elastotic fibers; may be a related entity
  • Necrobiosis lipodica: ill defined areas of disintegrating dermal collagen, surrounded by palisading lymphocytes and histiocytes, with thick walled vessels, usually in reticular dermis
Additional References