Difference between revisions of "Dermatologic neoplasms"

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m (moved Dermatologic cancer to Dermatologic neoplasms: neoplasms - includes benign tumours)
(+eccrine poroma)
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'''Dermatologic cancer''' can be deadly.  Collectively, they are the most common forms of cancer.
This article deals with '''dermatologic neoplasms'''.  It includes '''dermatologic cancer''', which can be deadly.  Collectively, dermatologic cancers are the most common form of cancer.


==Squamous cell carcinoma==
==Squamous cell carcinoma==
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Features:
Features:
*Pleomorphic nuclei with nucleoli.
*Pleomorphic nuclei with nucleoli.
*Duct-like structures.
*Duct-like structures - '''key feature'''.
*Extends from dermis into epidermis (follows path of a benign sweat duct).
*Extends from dermis into epidermis (follows path of a benign sweat duct).
   
   
Image: [http://commons.wikimedia.org/wiki/File:Eccrine_carcinoma_intermed_mag.jpg Eccrine carcinoma - intermed. mag. (WC)].
Image: [http://commons.wikimedia.org/wiki/File:Eccrine_carcinoma_intermed_mag.jpg Eccrine carcinoma - intermed. mag. (WC)].
==Eccrine poroma==
===General===
*Benign tumour arising from the distal sweat duct.
*Erythematous - gross.
===Microscopic===
Features:<ref>URL: [http://www.pathconsultddx.com/pathCon/diagnosis?pii=S1559-8675(06)70190-5 http://www.pathconsultddx.com/pathCon/diagnosis?pii=S1559-8675(06)70190-5]. Accessed on: 2 July 2010.</ref>
*Broad sheets of basaloid cells containing ductal structures - '''key feature'''.
*Biphasic stroma:
*#Edematous stroma.
*#Sclerotic stroma.
*Moderate nuclear pleomorphism.
*+/-Occasional mitoses.
Notes:
*Area above gland appears crusted.


==See also==
==See also==

Revision as of 19:13, 2 July 2010

This article deals with dermatologic neoplasms. It includes dermatologic cancer, which can be deadly. Collectively, dermatologic cancers are the most common form of cancer.

Squamous cell carcinoma

Precursor:[1]

  • Actinic keratosis (solar keratosis).
    • Clinical: yellow-brown scaly, patches, sandpaper sensation.
  • Keratocathoma - see non-malignant skin disease.
    • Some don't believe this entity exists.
      • These people sign this entity as low grade squamous cell carcinoma, keratoacanthoma type.[2]

Basal cell carcinoma

General

  • Very common.
  • Sun exposed skin.
  • Very rarely metastasizes - so rare... some don't think this is really a malignancy.

Clinical

  • Telangiectasias.
  • Raised pearly nodule.

As part of a syndrome

  • Nevoid basal cell carcinoma syndrome (NBCCS), AKA Gorlin syndrome.
  • Bazex syndrome (X-linked).[3]

Microscopic

Features:[4]

  • Artefactual separation of basal cell layer from underlying stroma.
  • Palisading hyperchromatic cells.

Notes:

DDx:

  • Trichoepithelioma.

Melanoma

  • AKA Malignant melanoma.
  • Main DDx: melanocytic lesions - especially if pigmented.
  • Known as the great mimicker in pathology; it may look like many things.

Clinical

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

Histology

  • Classic appearance of melanoma:
    • Loosely cohesive; mix of small nests of cells, single cells.
    • Mixed of spindle and ovoid cell morphology.
    • +/-Occasional large binucleated cells.
    • Cytoplasm: brown pigment (melanin).
    • Prominent (large) red nucleoli (like in serous carcinoma of the ovary).
    • Marked nuclear pleomorphism - variation in cell size, shape & staining (like in serous carcinoma of the ovary).
    • Nuclear pseudoinclusions (like in papillary thyroid carcinoma).

Notes:

  • Can look almost like anything.
    • Like it is said that sarcoidosis is in every internal medicine DDx... melanoma is every pathologic DDx.
  • Melanomas with:
    • An epitheloid cell morphology may mimic adenocarcinoma.
    • A spindle cell morphology may mimic spindle cell carcinoma (squamous cell carcinoma) or a sarcoma.

Stains

  • Fontana-Masson stain, stains melanin.[5]
    • May be useful to differentiate melanin from other brown stuff (e.g. lipofuscin, hemosiderin).

Electron microscopy

  • Melanosomes.

Image(s):

IHC

Standard panel:

  • S-100 +ve.
  • HMB-45 +ve.
  • Melan A (MART-1) +ve.

Notes:

  • The standard panel above is positive in other lesions also, e.g. cellular blue nevus.

Dermatofibrosarcoma protuberans

General

  • Abbreviated DFSP.
  • Dermal location.
  • Destroys adnexal structures.

Treatment

  • Wide excision.

Histology

  • Spindle cell morphology.
  • Contains adipose tissue within the tumour -- key feature.

IHC

Panel:[6]

  • CD34 +ve.
    • Usually negative in dermatofibroma.[7][8]
  • Factor XIIIa -ve.
    • Usually positive in dermatofibroma.[7][8]
  • S100 -ve (screen for melanoma).
  • caldesmin -ve (screen for muscle differentiation).
  • beta-catenin ???.
  • MIB-1 (proliferation marker) -- should not be confused with MIB1 a gene that regulates apoptosis.

DDx - histologic

  • Dermatofibroma - has entrapment of collagen bundles at the edge of the lesion.


Cutaneous T cell lymphoma

  • Abbreviated CTCL.
  • Mycosis fungoides - is a subtype (???).

Microscopic

  • Atypical lymphocytes:
    • Have folded "cerebriform" nuclei; Sezary-Lutzner cells.[9]
  • Grouping:
    • Nests in the epidermis - known as "Pautrier microabscesses".
    • Single lymphocytes in epidermis; "lymphocyte exocytosis".[10]
    • Short linear arrays of lymphocytes at the dermal-epidermal junction; "epidermotropism".[11]

Images:

Merkel cell carcinoma

General

Features:[12]

  • Rare.
  • Aggressive course/poor prognosis.
  • Neuroendocrine-like.[13]

Etiology:

  • Polyomavirus (?).[12]
  • Immunocompromised/immunosuppressed (e.g. organ transplant recipients).

Microscopic

Features:[14]

  • Nests or sheets or trabeculae.
  • Scant cytoplasm.
  • Nuclear moulding.
  • Multiple small nucleoli.
  • Usually mitotically active.

Image:

IHC

  • CK7 -ve, CK20 +ve

Eccrine carcinoma

General

  • Arises from the proximal sweat duct.

Microscopic

Features:

  • Pleomorphic nuclei with nucleoli.
  • Duct-like structures - key feature.
  • Extends from dermis into epidermis (follows path of a benign sweat duct).

Image: Eccrine carcinoma - intermed. mag. (WC).

Eccrine poroma

General

  • Benign tumour arising from the distal sweat duct.
  • Erythematous - gross.

Microscopic

Features:[15]

  • Broad sheets of basaloid cells containing ductal structures - key feature.
  • Biphasic stroma:
    1. Edematous stroma.
    2. Sclerotic stroma.
  • Moderate nuclear pleomorphism.
  • +/-Occasional mitoses.

Notes:

  • Area above gland appears crusted.

See also

References

  1. ↑ TN07 D6.
  2. ↑ RS. 17 May 2010.
  3. ↑ URL: http://emedicine.medscape.com/article/1101146-diagnosis. Accessed on: 6 May 2010.
  4. ↑ NEED REF.
  5. ↑ URL: http://education.vetmed.vt.edu/curriculum/VM8054/labs/Lab2/Examples/exfontana.htm. Accessed on: 5 May 2010.
  6. ↑ AP. May 2009.
  7. ↑ 7.0 7.1 PMID 7694515.
  8. ↑ 8.0 8.1 PMID 9129699.
  9. ↑ Klatt. AOP. P.385.
  10. ↑ URL: http://www.mdconsult.com/das/book/body/199872830-2/0/1709/I4-u1.0-B978-0-443-06694-8..50117-2--f2.fig. Accessed on: 6 May 2010.
  11. ↑ Klatt. AOP. P.385.
  12. ↑ 12.0 12.1 Calder, KB.; Smoller, BR. (May 2010). "New insights into merkel cell carcinoma.". Adv Anat Pathol 17 (3): 155-61. doi:10.1097/PAP.0b013e3181d97836. PMID 20418670.
  13. ↑ Pulitzer, MP.; Amin, BD.; Busam, KJ. (May 2009). "Merkel cell carcinoma: review.". Adv Anat Pathol 16 (3): 135-44. doi:10.1097/PAP.0b013e3181a12f5a. PMID 19395876.
  14. ↑ Humphrey, Peter A; Dehner, Louis P; Pfeifer, John D (2008). The Washington Manual of Surgical Pathology (1st ed.). Lippincott Williams & Wilkins. pp. 491. ISBN 978-0781765275.
  15. ↑ URL: http://www.pathconsultddx.com/pathCon/diagnosis?pii=S1559-8675(06)70190-5. Accessed on: 2 July 2010.
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