Difference between revisions of "Dermatologic neoplasms"
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==Melanoma== | ==Melanoma== | ||
===General=== | |||
*[[AKA]] ''Malignant melanoma''. | *[[AKA]] ''Malignant melanoma''. | ||
*Main DDx: [[melanocytic lesions]] - especially if pigmented. | *Main DDx: [[melanocytic lesions]] - especially if pigmented. | ||
*Known as the great mimicker in pathology; it may look like many things. | *Known as the great mimicker in pathology; it may look like many things. | ||
===Clinical=== | ====Clinical==== | ||
*''ABCD'' = asymmetric, borders (irregular), colour (black), diameter (large). | *''ABCD'' = asymmetric, borders (irregular), colour (black), diameter (large). | ||
=== | ===Microscopic=== | ||
Features: | |||
*Classic appearance of melanoma: | *Classic appearance of melanoma: | ||
**Loosely cohesive; mix of small nests of cells, single cells. | **Loosely cohesive; mix of small nests of cells, single cells. | ||
Line 62: | Line 64: | ||
*''Fontana-Masson stain'', stains melanin.<ref>URL: [http://education.vetmed.vt.edu/curriculum/VM8054/labs/Lab2/Examples/exfontana.htm http://education.vetmed.vt.edu/curriculum/VM8054/labs/Lab2/Examples/exfontana.htm]. Accessed on: 5 May 2010.</ref> | *''Fontana-Masson stain'', stains melanin.<ref>URL: [http://education.vetmed.vt.edu/curriculum/VM8054/labs/Lab2/Examples/exfontana.htm http://education.vetmed.vt.edu/curriculum/VM8054/labs/Lab2/Examples/exfontana.htm]. Accessed on: 5 May 2010.</ref> | ||
**May be useful to differentiate melanin from other brown stuff (e.g. lipofuscin, hemosiderin). | **May be useful to differentiate melanin from other brown stuff (e.g. lipofuscin, hemosiderin). | ||
*SOX10 +ve -- useful for diff. from excision scar.<ref name=pmid20653825>{{cite journal |author=Ramos-Herberth FI, Karamchandani J, Kim J, Dadras SS |title=SOX10 immunostaining distinguishes desmoplastic melanoma from excision scar |journal=J. Cutan. Pathol. |volume=37 |issue=9 |pages=944–52 |year=2010 |month=September |pmid=20653825 |doi=10.1111/j.1600-0560.2010.01568.x |url=}}</ref> | |||
===Electron microscopy=== | ===Electron microscopy=== |
Revision as of 03:21, 7 January 2011
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]
- Some don't believe this entity exists.
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:
- There are various subtypes: http://www.pathconsultddx.com/pathCon/diagnosis?pii=S1559-8675%2806%2970110-3.
DDx:
- Trichoepithelioma.
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.
Stains
- Fontana-Masson stain, stains melanin.[5]
- May be useful to differentiate melanin from other brown stuff (e.g. lipofuscin, hemosiderin).
- SOX10 +ve -- useful for diff. from excision scar.[6]
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:[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
- ↑ TN07 D6.
- ↑ RS. 17 May 2010.
- ↑ URL: http://emedicine.medscape.com/article/1101146-diagnosis. Accessed on: 6 May 2010.
- ↑ NEED REF.
- ↑ 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.