Skin nontumor

Dermal granulomatous and necrobiotic reaction patterns

Granuloma annulare


Resident / Fellow Advisory Board: Josephine K. Dermawan, M.D., Ph.D.
Editorial Board Member: Kiran Motaparthi, M.D.
Matthew Franklin, M.D.
Stephen Somach, M.D.

Topic Completed: 4 November 2021

Minor changes: 4 November 2021

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PubMed Search: Granuloma annulare skin [title]

Matthew Franklin, M.D.
Stephen Somach, M.D.
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Cite this page: Franklin M, Somach S. Granuloma annulare. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/skinnontumorgranulomaannulare.html. Accessed December 6th, 2021.
Definition / general
  • Idiopathic, self limited dermatosis typically characterized by erythematous papules and plaques and characterized histologically by palisaded or interstitial granulomatous inflammation
Essential features
  • Benign, self limited dermatosis characterized by erythematous papules and plaques, classically in an arciform or annular configuration
  • 2 classic morphologic patterns
    • Palisaded granulomas with central necrobiosis (collagen degradation) with peripheral histiocytes and admixed lymphocytes
    • Histiocytes intercalating among collagen bundles with interstitial mucin
  • Associations with hyperlipidemia and diabetes mellitus
  • No proven treatment for this recurring, idiopathic disease
ICD coding
  • ICD-10: L92.0 - granuloma annulare
Epidemiology
Sites
Pathophysiology
Etiology
Clinical features
Diagnosis
  • Histopathologic evaluation confirms diagnosis
Laboratory
Prognostic factors
Case reports
Treatment
Clinical images

Contributed by David Crowe, M.D.
Annular patch Annular patch

Annular patch

Annular plaque

Annular plaque

Erythematous annular plaque

Erythematous annular plaque

Microscopic (histologic) description
  • Palisaded or interstitial granulomatous inflammation with mucin unites all forms (Arch Dermatol 1977;113:1681)
  • Interstitial may be most common pattern (Indian Dermatol Online J 2018;9:409, Arch Dermatol 1977;113:1681)
  • Variable histopathology
  • Necrobiotic (collagenolytic) granulomas
    • Granulomas characterized by central areas of degraded collagen surrounded by lymphocytes and histiocytes, occasionally palisaded, are present in dermis
    • Occasional multinucleate giant cells
    • Deep variants
      • Subcutaneous
      • Pseudorheumatoid nodule
        • Nodules composed of palisaded granulomas with central eosinophilic material (degraded collagen) are separated by thickened collagen bundles
        • Minimal or absent mucin
  • Interstitial (or incomplete)
    • Busy dermis (interstitial lymphohistiocytic inflammation)
    • Histiocytes and lymphocytes arranged around vessels and intercalating between collagen bundles with conspicuous interstitial mucin
    • Lacks necrobiosis
    • Patch granuloma annulare more likely to be only or predominantly interstitial pattern (without palisaded granulomas) (J Cutan Pathol 2020;47:785)
  • Nonnecrobiotic (sarcoidal or tuberculoid)
    • Mimics sarcoidosis or tuberculous granulomas (Am J Dermatopathol 2015;37:547)
    • Increased mucin or eosinophils may suggest granuloma annulare over mimics
  • Eosinophils in ~40% of cases (J Cutan Pathol 1985;12:13)
  • In generalized granuloma annulare, interstitial and palisading patterns roughly equal in frequency (Ann Dermatol 2009;21:113)
  • Transepithelial excretion of altered collagen in perforating granuloma annulare
  • Minimal epidermal changes
  • Potential overlap with other granulomatous disorders
Microscopic (histologic) images

Contributed by Stephen Somach, M.D.
Deep dermal palisaded granuloma

Deep dermal palisaded granuloma

Reticular dermal palisaded granuloma

Reticular dermal palisaded granuloma

Increased dermal mucin in necrobiotic zone

Increased dermal mucin in necrobiotic zone

Predominantly sarcoidal granulomas Predominantly sarcoidal granulomas

Predominantly sarcoidal granulomas


Interstitial histiocytic infiltrate

Interstitial histiocytic infiltrate

Small interstitial histiocytes

Small interstitial histiocytes

Palisaded granuloma with fibrinoid collagen degeneration

Palisaded
granuloma with
fibrinoid collagen
degeneration

Deep palisaded granuloma with fibrinoid degeneration

Deep palisaded granuloma with fibrinoid degeneration

Virtual slides

Images hosted on other servers:

Palisaded granuloma annulare

Alcian blue, granuloma annulare

Immunofluorescence description
Positive stains
Electron microscopy description
Videos

Granuloma Annulare
Dr. James Carton

Sample pathology report
  • Skin, left forearm, punch biopsy:
    • Consistent with granuloma annulare (see comment)
    • Comment: Sections show a punch biopsy specimen with a normal epidermis. Within the reticular dermis is a palisaded array of histiocytes associated with central collagen degeneration and mucin deposition.
Differential diagnosis
Additional references
Board review style question #1

A 44 year old woman presents with an eruption involving her proximal upper extremities characterized by slightly erythematous papules coalescing into annular and arciform plaques. Which of the following systemic abnormalities is most strongly associated with granuloma annulare?

  1. Obesity
  2. Hematologic malignancy
  3. HIV
  4. Hyperlipidemia
  5. Intravenous drug abuse
Board review style answer #1
D. Hyperlipidemia

Comment Here

Reference: Granuloma annulare
Board review style question #2

A 51 year old woman with diabetes presents with skin colored papules on her chest and abdomen that have a vague annular configuration. A 4 mm punch biopsy is taken from her abdomen. Sections demonstrate palisaded histiocytes forming granulomas with peripheral lymphocytes and central eosinophilic material. Which interstitial extracellular substance would you expect to be most prevalent in this granulomatous dermatosis?

  1. Calcium
  2. Mucin
  3. Urate crystals
  4. Lipid
  5. Amyloid
Board review style answer #2
B. Mucin

Comment Here

Reference: Granuloma annulare
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