Difference between revisions of "Dermal cysts"

From Libre Pathology
Jump to navigation Jump to search
(create)
 
(mv dermatofibroma to nonmalign. article)
Line 91: Line 91:
===DDx===
===DDx===
*May resemble pemphigus vulgaris.
*May resemble pemphigus vulgaris.
==Dermatofibroma==
===General===
*AKA fibrous histiocytoma.
*Reactive process -- it is ''not'' a neoplasm.
*Usually assoc. with previous trauma.
**in women... usually legs.


==Epidermal inclusion cyst==
==Epidermal inclusion cyst==

Revision as of 12:56, 8 June 2010

Dermal cysts happen and are common. Dermatopathologists can diagnose 'em.

Cysts

Common types:[1]

  • Epidermal cyst (sebaceous cyst) -- most common.
  • Pilar (tricheilemmal) cyst.
  • Dermoid cyst.
  • Ganglion cyst.
  • Milicem.

EM, SJS, TEN

  • SJS and TEN are on a spectrum, EM is considered separate.

Erythema multiforme (EM)

Stevens-Johnson Syndrome (SJS) and Toxic Epidermal Necrolysis (TEN)

Rx causes of SJS:

  • NSAIDs,
  • anticonvulsants,
  • sulfonamides,
  • penicillins.

TEN more severe form SJS.

Definition:

  • >30% sheet-like epidermal detachment, diffuse erythema, severe mucous membrane involvement
  • most TEN (80%) Rx-related, only 50% of SJS Rx-related

Venous lake

  • Dilated vein.

Microscopic

Features:[2]

  • Lined by endothelium.
  • Blood in lumen.
  • +/-Fibrin in lumen.

DDx:

  • Angiokeratoma.
    • Ectatic superficial dermal vessels.
    • Irregular acanthosis.
    • Longer rete ridges.

Neurofibromatosis (von Recklinghausen's disease)

Etiology

  • Genetic - autosomal dominant disorder.

Management

  • Follow for malignant transformation of neurofibroma --> neurofibrosarcoma.

Treatment

  • Excise suspicious lesions & lesions that are painful.

Collagenous fibroma

General

  • Benign.
  • Used to be known as desmoblastic fibroblastoma.

Epidemiology

  • May be on the lip.

Histo.[3][4]

  • acellular stroma with abundant collagen.
  • no nuclear atypia.

Dermatomyositis

Gross

  • Have lesions on the knuckle - Gottron's papulle

Histology

  • Lymphocytic interface dermatitis (inflammation at the dermal-epidermal junction).
  • Loss of rete ridges.

Systemic lupus erythematosus

  • Lymphocytic interface dermatitis.[5]

Familial benign pemphigus

  • AKA Hailey-Hailey disease. Was described by two brothers - that's why it is Hailey-Hailey.[6]

Etiology

  • Autosomal dominant with incomplete penetration.[6]
  • Desmosomal defect - due to mutation in the gene ATP2C1.[6]

Clinical

  • Chest.
  • Intriginous regions (?sp).
  • Typically presents individual in their 30s and 40s.[6]

Histology

  • Hair folicles spared.
  • Epidermis thickened.

DDx

  • May resemble pemphigus vulgaris.

Epidermal inclusion cyst

  • Need to see keratin.

Image:

Micro

  • Trapped collagen bundles at edge of lesion with surrounded by fibroblasts.
  • Red cells.

DDx: dermatofibrosarcoma (if lesion is large)

See also

References

  1. TN07 D5
  2. Weedon's Skin Pathology. 3rd Ed. P.895.
  3. [1]
  4. [Sternberg P.161]
  5. JAH 20 Feb 2009.
  6. 6.0 6.1 6.2 6.3 http://emedicine.medscape.com/article/1063224-overview