Non-malignant skin disease

From Libre Pathology
Revision as of 12:10, 13 May 2010 by Michael (talk | contribs) (mv'ed here from main skin article)
Jump to navigation Jump to search

Non-malignant skin disease is relatively common. The pathology may or may not be specific. Some diseases require clinical information to diagnose.

General classification (Inflammatory)

  • Bullous.
  • Interface.
  • Nodular & diffuse.
  • Spongiotic.
  • Vasculitis.
  • Perivascular.
  • Panniculitis.
  • Psoriasiform.

Tabular comparison of inflammatory skin disease (adapted from Brister[1]):

Pattern Key histologic feature Subclassifications Example
Bullous "Empty space" -Subcorneal
-Suprabasillar
-Subepidermal		 -?
-?
-?
Interface Inflammation at DE junction -Vacuolar (minimal)
-Lichenoid (band-like)		 -Erythema multiforme
-Lichen simplex chronicus (LSC)
Nodular & diffuse Nodular & diffuse ?
Spongiotic Edema between keratinocytes -Acute
-Subacute
-Chronic		 -Poison Ivy
-Nummular dermatitis
-Atopic dermatitis
Vasculitis Inflammation of vessel wall ? ?
Perivascular Inflammation around vessels ? ?
Panniculitis Inflamm. of SC tissue -Septal
-Nodular
Psoriasiform Epidermal thickening
and long rete ridges		 -Regular
-Irregular

Notes:

  • DE junction = dermal-epidermal junction.
  • The "empty space" in bullous disease in situ is filled with fluid.

Lichen planus

  • Oral pathology.

Microscopy

Features:

  • Loss of rete ridges.
  • Loss of basal cells (stratum basale).
  • Interface dermatitis (lymphocytes at dermal-epidermal junction).

Ref.: http://emedicine.medscape.com/article/1078327-overview.

Lichen sclerosus

  • AKA chronic atrophic vulvitis (when vulvar lesion).

Etiology

  • Scratching due to pruritis.

Histology

Key feature:[2]

  • Subepithelial fibrosis.

Lichen simplex chronicus

Histology

Key features:[3]

  • Acanthosis (epithelial thickening).
  • Hyperkeratosis.

Seborrheic keratosis

General

  • Benign.
  • Common.

Epidemiology

  • Old people.

Gross

  • "Stuck-on" appearance.

Images:

Molluscum contagiosum

  • Etiology: caused by molluscum contagiosum virus.

Micro

  • A suprabasilar epidermal lesion consisting of "molluscum bodies", i.e. molluscum bodies are found above the stratum basale.[4]
  • Molluscum bodies:
    • Large cells with abundant granular eosinophilic cytoplasm.
    • Small peripheral nucleus.

Note:

  • Molluscum bodies vaguely resemble signet ring cells -- but:
    • Cytoplasm eosinophilic and granular.
    • Nucleus usually smaller than in signet ring cell.
    • Molluscum bodies are only the epidermis - an uncommon place to find SRCs without finding them elsewhere.
  • The granular eosinophilic cytoplasm represents accumulated virons.

Dermal nevus

  • Think melanoma.

Clinical: ABCD = asymmetric, borders (irregular), colour (black), diameter (large).

Micro

Features:[5]

  • Symmetrical lesion.
  • "Matures" with depth - less cellular, less atypia.
  • No destruction of surrounding structures.
  • Only in dermis key feature.
    • Otherwise it is something else, e.g. dermal nevus, junctional nevus.

Microscopic

  • Basaloid cells mixed with squamous cells.
  • Keratin-filled invaginations.
  • Horn cysts - intraepidermal, brown globule-like structures.
    • Melanocytes at the dermoepidermal junction.[6]

Images:

Pilomatrixoma

General

  • Benign skin tumour.
  • Most common solid skin tumour of children.[7]

Clinical:

  • Hard nodule - calcification.
  • +/-Painful. (???)

Treatment:

  • Surgical excision.[7]

Microscopic

Features:[8]

  • Location: lower dermis/subcutaneous fat; thus, usu. surrounded by connective tissue.
  • Sharpy demarcated island of cells.
  • Calcification in 75% - with calcium staining (von Kossa).
  • Cells:[9]
    • Basaloid epithelial cells - have prominent nucleoli.
    • Anucleate squamous cells ("ghost cells").
  • Giant cell foreign body type granulomas (form in reaction to keratin).

Notes:

  • Keratin a prominent feature on cytology - lots of orange stuff.

Images:

DDx:

  • Epidermal inclusion cyst.

Syringoma

  • Benign sweat duct tumour. (???)
  • Eccrine differentiation.

Microscopic

Features:[10]

  • Proliferation of benign ducts with lined by a bilayer (as in normal sweat ducts) with abnormal architecture:
    • Tadpole like appearing ducts.

Image:

Inverted follicular keratosis

  • Benign skin lesions.
    • May mimic squamous cell carcinoma or basal cell carcinoma.[11]

Images:

Bullous disease

Main article: Bullous disease

Cysts

Main article: Dermal cysts

See also

References

  1. ↑ Brinster NK (March 2008). "Dermatopathology for the surgical pathologist: a pattern based approach to the diagnosis of inflammatory skin disorders (part I)". Adv Anat Pathol 15 (2): 76–96. doi:10.1097/PAP.0b013e3181664e8d. PMID 18418089.
  2. ↑ PBoD P.1065-6
  3. ↑ PBoD P.1065-6
  4. ↑ http://www.missionforvisionusa.org/anatomy/2006/08/what-is-molluscum-contagiosum.html
  5. ↑ need ref
  6. ↑ http://emedicine.medscape.com/article/1059477-overview
  7. ↑ 7.0 7.1 http://emedicine.medscape.com/article/1058965-overview
  8. ↑ http://emedicine.medscape.com/article/1058965-diagnosis
  9. ↑ http://www.bccancer.bc.ca/HPI/CE/cytotechnology/cytosleuthquiz/nongyne/ngcase02d.htm
  10. ↑ URL: http://emedicine.medscape.com/article/1059871-diagnosis. Accessed on: 12 May 2010.
  11. ↑ URL: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC475744/. Accessed on: 11 May 2010.
Retrieved from "https://librepathology.org/w/index.php?title=Non-malignant_skin_disease&oldid=106"