Dermatologic neoplasms
Revision as of 17:25, 20 March 2011 by Michael (talk | contribs) (→Basal cell carcinoma: more, refs)
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
Main article: Squamous carcinoma
General
Precursor:[1]
- Actinic keratosis (solar keratosis).
- Clinical: yellow-brown scaly, patches, sandpaper sensation.
Risk factors:[1]
- Sun exposure.
- Immune suppression (e.g. organ transplant recepients).
Notes:
- 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]
- Some don't believe this entity exists.
Microscopic
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]
- Nest of hyperchromatic (i.e. blue) cells (similar in appearance to basal cells) with:
- Palisading of cells at the edge of the cell nests.
- Artefactual separation of cells (forming the nests) from the underlying stroma.
Notes:
- Palisading = the long axes of the cells are alined and the axes are perpendicular to the interface between the (basaloid cell) nests and stroma.
- There are various subtypes: http://www.pathconsultddx.com/pathCon/diagnosis?pii=S1559-8675%2806%2970110-3.
DDx:
- Trichoepithelioma - no artefactual cleft.[4]
Melanoma
General
- 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).
Microscopic
Features:
- 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.
Electron microscopy
- Melanosomes.
Image(s):
Stains
- Fontana-Masson stain, stains melanin.[5]
- May be useful to differentiate melanin from other brown stuff (e.g. lipofuscin, hemosiderin).
IHC
Standard panel:
- S-100 +ve.
- HMB-45 +ve.
- Melan A (MART-1) +ve.
Others:
- SOX10 +ve -- useful for diff. from excision scar.[6]
- SOX-10 = pan-schwannian and melanocytic marker.
Notes:
- The standard panel above (S-100, HMB-45, MART-1) is also positive in other lesions, 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:[7]
- CD34 +ve.
- Factor XIIIa -ve.
- 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 B-cell lymphoma
- Abbreviated CBCL.
General
- CBCL is less common than cutaneous T-cell lymphoma (CTCL).[10]
Microscopic
Features:
- Dermal lymphoid infiltrate.
- "Grenz zone" - space between the epidermis and the dermal infiltrate - key feature.
IHC
- B cell and T cell markers.
Cutaneous T-cell lymphoma
- Abbreviated CTCL.
General
- Mycosis fungoides - is a subtype (???).
- CTCL is more common than cutaneous B-cell lymphoma (CBCL).[11][12]
Microscopic
- Atypical lymphocytes:
- Have folded "cerebriform" nuclei; Sezary-Lutzner cells.[13]
- Grouping:
Images:
Merkel cell carcinoma
General
Features:[15]
- Rare.
- Aggressive course/poor prognosis.
- Neuroendocrine-like.[16]
Etiology:
- Polyomavirus (?).[15]
- Immunocompromised/immunosuppressed (e.g. organ transplant recipients).
Microscopic
Features:[17]
- 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:[18]
- 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.
Kaposi sarcoma
- See Kaposi sarcoma.
See also
References
- ↑ 1.0 1.1 Kumar, Vinay; Abbas, Abul K.; Fausto, Nelson; Aster, Jon (2009). Robbins and Cotran pathologic basis of disease (8th ed.). Elsevier Saunders. pp. 1180. ISBN 978-1416031215.
- ↑ RS. 17 May 2010.
- ↑ URL: http://emedicine.medscape.com/article/1101146-diagnosis. Accessed on: 6 May 2010.
- ↑ 4.0 4.1 Kumar, Vinay; Abbas, Abul K.; Fausto, Nelson; Aster, Jon (2009). Robbins and Cotran pathologic basis of disease (8th ed.). Elsevier Saunders. pp. 1180-1. ISBN 978-1416031215.
- ↑ URL: http://education.vetmed.vt.edu/curriculum/VM8054/labs/Lab2/Examples/exfontana.htm. Accessed on: 5 May 2010.
- ↑ Ramos-Herberth FI, Karamchandani J, Kim J, Dadras SS (September 2010). "SOX10 immunostaining distinguishes desmoplastic melanoma from excision scar". J. Cutan. Pathol. 37 (9): 944–52. doi:10.1111/j.1600-0560.2010.01568.x. PMID 20653825.
- ↑ AP. May 2009.
- ↑ 8.0 8.1 PMID 7694515.
- ↑ 9.0 9.1 PMID 9129699.
- ↑ URL: http://emedicine.medscape.com/article/1099540-overview. Accessed on: 24 August 2010.
- ↑ URL: http://emedicine.medscape.com/article/1099540-overview. Accessed on: 24 August 2010.
- ↑ URL: http://emedicine.medscape.com/article/1098342-overview. Accessed on: 24 August 2010.
- ↑ 13.0 13.1 Klatt, Edward C. (2006). Robbins and Cotran Atlas of Pathology (1st ed.). Saunders. pp. 385. ISBN 978-1416002741.
- ↑ 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.
- ↑ 15.0 15.1 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.
- ↑ 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.
- ↑ 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.
- ↑ URL: http://www.pathconsultddx.com/pathCon/diagnosis?pii=S1559-8675(06)70190-5. Accessed on: 2 July 2010.