Panniculitis
Jump to navigation
Jump to search
Panniculitis is inflammation of the adipose tissue and fits into the larger category of inflammatory skin disorders. It is encountered in dermatopathology specimens.
Classification
- Lobular - involve fat lobules.
- Septal - involve interlobular septae.
A simple general DDx
Septal:
Lobular:
- Erythema induratum.
- Self-inflicted trauma (factitial panniculitis).
- Systemic lupus erythematosus.
- Other.
DDx by type
Septal:
- Erythema nodosum.
- Scleroderma panniculitis, also morphea profunda.[1]
Lobular:[1]
- Infectious panniculitis.
- Erythema induratum.
- Lupus panniculitis.
- Pancreatic panniculitis.
- Alpha1-antitrypsin deficiency.
- Subcutaneous fat necrosis of the newborn.
- Sclerema neonatorum.
Specific conditions
Erythema nodosum
Causes - mnemonic NODOSUM:[2]
- NO cause (idiopathic) ~ 55% of cases.
- Drugs (sulfonamides, amoxicillin, oral contraceptives) ~ 5% of cases.
- Other infections - group A streptococci (streptococcal pharyngitis), Yersinia, chlamydia, mycobacteria, others ~ 30% of cases.
- Sarcoidosis ~ 7% of cases.
- Ulcerative colitis & Crohn's disease ~ 2% of cases.
- Malignancy (leukemia, Hodgkin's lymphoma) ~ 1% of cases
Microscopic
- Expanded septa between fat lobules - key (low power) feature.
- Neutrophils.
- Lymphocytes.
- Histiocytes.
- Fibrin.
Notes:
- No vasculitis.
- +/-Granulomas.[6]
DDx:
Images:
Morphea profunda
- AKA scleroderma panniculitis.
General
Main article: Scleroderma
- Think about the name... sclerotic (sclero-) dermis (-derma).
Microscopic
Features:[1]
- Septal fibrosis/expansion - key feature.
- Classically ~2-3x an adiposcyte thick.
- +/-Deep dermal perivascular lymphocytes and plasma cells.
DDx:
Erythema induratum
General
Features:[4]
- Uncommon.
- Etiology: unknown.
- Brinster[1] suggests an association, in some cases, with Mycobacterium tuberculosis and hepatitis C.
Clinical:[5]
- Classic location: posterior shins.
- Ulcerates and scars.
Microscopic
Features:[4]
- Predominantly lobular process with:[3]
- Necrotizing granulomatous inflammation.
- Necrotizing vasculitis of small/medium sized vessels (early).
DDx:
- Infection.
Images:
Stains
- AFB stain - exclude Tuberculosis.
See also
References
- ↑ 1.0 1.1 1.2 1.3 Brinster, NK. (Nov 2008). "Dermatopathology for the surgical pathologist: a pattern-based approach to the diagnosis of inflammatory skin disorders (part II).". Adv Anat Pathol 15 (6): 350-69. doi:10.1097/PAP.0b013e31818b1ac6. PMID 18948765.
- ↑ 2.0 2.1 Schwartz, RA.; Nervi, SJ. (Mar 2007). "Erythema nodosum: a sign of systemic disease.". Am Fam Physician 75 (5): 695-700. PMID 17375516.
- ↑ 3.0 3.1 URL: http://www.medscape.com/viewarticle/440356_8. Accessed on: 11 September 2011.
- ↑ 4.0 4.1 4.2 Kumar, Vinay; Abbas, Abul K.; Fausto, Nelson; Aster, Jon (2009). Robbins and Cotran pathologic basis of disease (8th ed.). Elsevier Saunders. pp. 1199. ISBN 978-1416031215.
- ↑ 5.0 5.1 Mitchell, Richard; Kumar, Vinay; Fausto, Nelson; Abbas, Abul K.; Aster, Jon (2011). Pocket Companion to Robbins & Cotran Pathologic Basis of Disease (8th ed.). Elsevier Saunders. pp. 609. ISBN 978-1416054542.
- ↑ 6.0 6.1 URL: http://missinglink.ucsf.edu/lm/DermatologyGlossary/erythema_nodosum.html. Accessed on: 11 September 2011.