Dermatopathology

From Libre Pathology
Revision as of 16:31, 1 September 2011 by Michael (talk | contribs) (→‎Non-malignant: +more)
Jump to navigation Jump to search

Dermatopathology is the pathology of skin.

Pathology is a significant part of dermatology and dermatologists spend five years in residency. So, it is a huge area.

Layers of the skin

  • Epidermis - outer most layer, avascular, separated from dermis by a basement membrane, epithelial tissue.
  • Dermis - below the epidermis, vascular, separated from the epidermis by a basement membrane, connective tissue.
  • Subdermis - below the dermis, connective tissue.

Layers of epidermis

Epidermis layers - from the surface to epidermal-dermal junction:

  • Stratum corneum.
  • Stratum lucidum.
    • Present only in "thick" skin.[1]
  • Stratum granulosum.
  • Stratum spinosum (aka prickle layer).
  • Stratum basale (germinativum).

Mnemonic: Corn Lovers Grow Several Bales.

Adnexal structures

The top five structures of the skin:[2]

Structure / Attribute Histomorphology Function IHC Other Image
Eccrine gland clusters of tubular structures, pale cytoplasm thermoregulation (cooling) CK7+, CEA+, CAM5.2+, EMA+ ? ?
Apocrine gland apical snouts, tubular structures ear wax, body odor ? ? ?
Sebaceous gland clusters of cells side-by-side, pale fluffy cytoplasm grease hair, sexual lubrication ? assoc. with hair follicle ?
Hair follicle linear structure keep individual warm ? assoc. with sebaceous glands ?
Nail epidermal structure ? look pretty ? ? ?

Ducts vs. glands:[3]

  • Eccrine glands - spindle-shaped myoepithelial cells surround luminal cells.
  • Eccrine ducts - cuboidal type subepithelial cells.

Common terms

  • Acanthosis = thickening of the prickle layer (stratum spinosum) of epidermis.[4]
  • Parakeratosis = retention of nuclei in the stratum corneum, normal in mucous membranes
  • Dyskeratosis = abnormal keratinization, often refers to keratinization below the stratum granulosum; keratinization above may be abnormal (dependent on body site).
  • Spongiosis = epidermal intercellular edema;[5] cells appear to have a clear halo around 'em.

Images:

Skin diseases

Cancer

Main article: Dermatologic cancer

Skin cancer is very common. The basic DDx of a malignant skin lesion is:

Non-malignant disease

Main article: Non-malignant skin disease

Non-malignant skin disease is common. It is the domain of dermatologists. It can be scary for general anatomical pathologist because the differential diagnosis is often broad, and, it's generally not something the general anatomical pathologist sees a lot of.

Bullous diseases, e.g. pemphigus vulgaris, is dealt with in the bullous disease article.

Common entities

Non-malignant
Entity Key histologic feature Other features Clinical Stains/IHC DDx Other Image
Seborrheic keratosis (SK) horn cysts (intraepidermal collections of keratin) hyperkeratosis, brown granular material at the DE junction, sharply demarcated stuck on appearance none Fibroepithelial polyp Leser–Trélat sign = many SKs in malignancy (WC)
Dermatofibroma fibrous bundles esp. at edge of lesion "dirty fingers" = acanthosis + basal keratinocyte hyperpigmentation +/-trauma Hx CD34-, Factor VIIIa+ DFSP very common (pacificderm.org)
Fibroepithelial polyp (skin tag) on a stalk (epithelium on 3+ sides) no horn nests, no hyperkeratosis raised lesion none seborrheic keratosis very common (dermatlas.med.jhmi.edu)
Lipoma mature adipocytes - uniform size var. of size may be seen, should prompt search for lipoblasts mobile subcutaneous mass S100 (???) liposarcoma variants: angiolipoma (blood vessels), myolipoma (muscle) (ahajournals.org)
Angiofibroma fibrotic dermis, dilated capillaries enlarged (stellate fibroblasts) dome-shaped - face, boys nosebleeds (nasopharyngeal angiofibroma) Stains/IHC DDx assoc. tuberous sclerosis Angiofibroma (drdittmar.lu)
Keloid thick collagen bundles - surrounded by paler staining fibroblasts replaces adnexal structures site of previous trauma, esp. in blacks none dermatofibroma (???) Other (ucsf.edu).
Pre-malignant/malignant
Entity Key histologic feature Other features Clinical Stains/IHC DDx Other Image
Actinic keratosis epidermal atypia, esp. (basal) nuclear enlargement var. of size, shape and staining yellow-brown scaly none squamous carcinoma squamous carcinoma (WC)

Presentations

Leukoplakia

DDx:[6]

Skin disease and systemic conditions

Acanthosis nigricans

Associated with: diabetes mellitus,[7] malignancy.[8]

Microscopic

Features BPH:[8]

  • Basal cell hyperpigmentation.
  • Prominent rete ridges.
  • Hyperkeratosis.

Images:

Others

References

  1. ↑ Busam, Klaus J. (2009). Dermatopathology: A Volume in the Foundations in Diagnostic Pathology Series (1st ed.). Saunders. pp. 1. ISBN 978-0443066542.
  2. ↑ Busam, Klaus J. (2009). Dermatopathology: A Volume in the Foundations in Diagnostic Pathology Series (1st ed.). Saunders. pp. 4-8. ISBN 978-0443066542.
  3. ↑ HJ. 27 Feb 2009.
  4. ↑ http://dictionary.reference.com/browse/acanthosis
  5. ↑ Cotran, Ramzi S.; Kumar, Vinay; Fausto, Nelson; Nelso Fausto; Robbins, Stanley L.; Abbas, Abul K. (2005). Robbins and Cotran pathologic basis of disease (7th ed.). St. Louis, Mo: Elsevier Saunders. pp. 1230. ISBN 0-7216-0187-1.
  6. ↑ Cotran, Ramzi S.; Kumar, Vinay; Fausto, Nelson; Nelso Fausto; Robbins, Stanley L.; Abbas, Abul K. (2005). Robbins and Cotran pathologic basis of disease (7th ed.). St. Louis, Mo: Elsevier Saunders. pp. 1065. ISBN 0-7216-0187-1.
  7. ↑ URL: http://www.emedicine.com/derm/topic1.htm, URL: [1].
  8. ↑ 8.0 8.1 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. 596. ISBN 978-1416054542.
  9. ↑ TN07 D23.
  10. ↑ TN07 D23.
Retrieved from "https://librepathology.org/w/index.php?title=Dermatopathology&oldid=7010"