Difference between revisions of "Dermatologic neoplasms"

From Libre Pathology
Jump to navigation Jump to search
(→‎Keratoacanthoma: split-out)
Line 630: Line 630:


==Keratoacanthoma==
==Keratoacanthoma==
*Abbreviated ''KA''.
{{Main|Keratoacanthoma}}
===General===
*Generally considered to be benign.
**Rare reports of [[metastases]] suggesting it may be a form of [[squamous cell carcinoma]].<ref>{{cite journal |author=Mandrell JC, Santa Cruz D |title=Keratoacanthoma: hyperplasia, benign neoplasm, or a type of squamous cell carcinoma? |journal=Semin Diagn Pathol |volume=26 |issue=3 |pages=150–63 |year=2009 |month=August |pmid=20043514 |doi= |url=}}</ref>
 
====Clinical====
*May grow rapidly (weeks or months) then involute.
*Main DDx is [[squamous cell carcinoma]].
*Exophytic lesion, well-circumscribed.
 
===Microscopic===
Features:<ref name=Ref_Klatt378>{{Ref Klatt|378}}</ref>
*Expansion of stratum spinosum - pushing [[tongue]]-like downward growth of epidermis into the dermis.
*Keratin collection ("keratin plug") at the center of lesion-superficial aspect.
*Cells have glassy pink cytoplasm.
*Minimal/no nuclear atypia.
 
Note:
*Classically described as a "volcano lesion" with pale pink cells.
*May have features of regression - [[PMN]]s, fibrosis (???).
 
DDx:<ref name=Ref_Derm379>{{Ref Derm|379}}</ref>
*[[Verruca vulgaris]].
*Conventional [[squamous cell carcinoma of the skin]] with a cup-shape.
*[[Pseudoepitheliomatous hyperplasia]].
 
====Image====
<gallery>
Image:Skin_keratoacanthoma_whole_slide.jpg | Keratoacanthoma. (WC)
</gallery>


==Sebaceous adenoma==
==Sebaceous adenoma==

Revision as of 11:40, 4 July 2013

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

An introduction to dermatopathy is found in the dermatopathology article. Non-malignant disease is covered in the non-malignant skin disease article.

The Big Three malignant

Basal cell carcinoma

Squamous cell carcinoma of the skin

  • Abbreviated skin SCC, SCC of the skin, and SCC of skin.

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 recipients).

Notes:

  • Keratoacanthoma.
    • Some don't believe this entity exists.
      • These people sign this entity as low grade squamous cell carcinoma, keratoacanthoma type.[2]

Microscopic

High risk features - for SCC of the skin:[3]

  • Primary site is ear or lip.†
  • Clark level IV/V = reticular dermis or deeper.
  • >=2 mm thickness -- measured from granular layer (stratum granulosum) or ulcer base to deepest aspect.
  • Lymphovascular invasion.
  • Perineural invasion.
  • Poorly differentiated.

Note:

  • † The words used are "hair-bearing lip" - but there is considerable confusion about this as the AJCC manual contradicts itself.[4]

DDx:

Bowen disease

Bowen disease is squamous cell carcinoma in situ of the skin.

Histologic DDx of Bowen disease:

Images

IHC

Bowen's disease panel:

Sign-out

Invasive SCC

SKIN, SITE, BIOPSY: 
- MODERATELY-DIFFERENTIATED INVASIVE SQUAMOUS CELL CARCINOMA, SEE COMMENT. 
- NEGATIVE FOR LYMPHOVASCULAR INVASION.
- NEGATIVE FOR PERINEURAL INVASION.

COMMENT: 
The nearest margin (lateral margin) is 1 mm.  The tumour is 9 mm in maximal dimension.
SKIN, SITE, BIOPSY: 
- INVASIVE SQUAMOUS CELL CARCINOMA, SEE TUMOUR SUMMARY.

TUMOUR SUMMARY:
Histologic type: squamous cell carcinoma, type not otherwise specified.
Histologic grade: moderately differentiated.
Greatest dimension: ___ cm.
Tumour thickness: ___ mm.
Peripheral margin: negative for invasive carcinoma and in situ carcinoma.
Deep margin (invasive component): negative for invasive carcinoma.
Closest margin: deep margin, ___ mm.
Lymphovascular invasion: not identified.
Perineural invasion: not identified.

Bowen's disease

SKIN LESION, RIGHT EAR, BIOPSY:
- SQUAMOUS CELL CARCINOMA IN SITU (BOWEN'S DISEASE), INCOMPLETELY EXCISED.

COMMENT:
Complete excision of the lesion is recommended.

Melanoma

General

  • Known as the great mimicker in pathology; it may look like many things.

Microscopic

Features:

  • Classic appearance of melanoma:
    • Loosely cohesive; mix of small nests of cells, single cells.
    • Usu. 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).
    • Often marked nuclear pleomorphism - variation in cell size, shape & staining (like in serous carcinoma of the ovary).
    • Nuclear pseudoinclusions (like in papillary thyroid carcinoma).

Less common malignant

Dermatofibrosarcoma protuberans

  • Abbreviated DFSP.

General

  • Dermal location.
  • Destroys adnexal structures.
  • Occasionally transforms to a (more aggressive) fibrosarcoma.[8]

Treatment:[9]

  • Wide excision.
  • May include imatinib (Gleevec).

Gross

Features:[10]

  • Firm plaque, often bosselated, usually on the trunk.
  • +/-Ulceration.

Images:

Microscopic

Features:[9]

  • Dermal spindle cell lesion with storiform pattern.
    • Spokes of the wheel-pattern.
  • Contains adipose tissue within the tumour -- key feature.
    • Described as "honeycomb pattern" and "Swiss cheese pattern".

Notes:

  • Adnexal structure within tumour are preserved -- this is unusual for a malignant tumour -- important.


DDx:

DDx of storiform pattern:

Images

www:

IHC

Panel:[12]

  • CD34 +ve.
    • Usually negative in dermatofibroma.[13][14]
  • Factor XIIIa -ve.
    • Usually positive in dermatofibroma.[13][14]
  • S100 -ve (screen for melanoma).
  • Caldesmin -ve (screen for muscle differentiation).
  • Beta-catenin. (???)
  • MIB1 (proliferation marker).
    • Should not be confused with MIB-1 a gene that regulates apoptosis.

Molecular

A characteristic translocation is seen:[15] t(17;22)(q22;q15) COLA1/PDGFB.

Cutaneous B-cell lymphoma

  • Abbreviated CBCL.

General

  • CBCL is less common than cutaneous T-cell lymphoma (CTCL).[16]

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).[17][18]

Stages - like Kaposi sarcoma:

  • Patch.
  • Plaque.
  • Nodular.

Microscopic

  • Atypical lymphocytes:
    • Have folded "cerebriform" nuclei; Sezary-Lutzner cells.[19]
  • Grouping:
    • Nests in the epidermis - known as "Pautrier microabscesses".
    • Single lymphocytes in epidermis - without accompanying edema.
    • Short linear arrays of lymphocytes along the basal layer of the epidermis; "epidermotropism".[19]

DDx:

Images

www:

IHC

Key stain:

Other stains:

  • CD3 +ve.
  • CD8 -ve.
  • CD20 -ve (to r/o significant B cell population).
  • CD30 -ve.
  • CD5 +ve.
  • CD7 -ve (often lost first in T cell lymphomas).
  • Ki-67 high.
  • CD56 -ve.

Merkel cell carcinoma

  • Abbreviated MCC.

General

Features:[21]

  • Rare.
  • Aggressive course/poor prognosis.
  • Neuroendocrine-like.[22]

Etiology:

  • Most caused by Merkel cell polyomavirus.[23][21]
  • Immunocompromised/immunosuppressed (e.g. organ transplant recipients).

Microscopic

Features:[24]

  • Neuroendocrine nuclear features - round nucleus, small nucleoli/no nucleolus, stippled chromatin - key feature.
  • Typically medium size cells ~3x resting lymphocyte.
    • May be small or large.
  • Architecture: nests, sheets or trabeculae.
  • Scant cytoplasm.
  • Abundant mitoses. †
  • +/-Nuclear moulding.
    • Nuclei of adjacent cells conform to one another.
  • +/-Tumour infiltrating lymphocytes. ‡

Notes:

  • † >10 mitoses/HPF = poor prognosis - definition suffers from HPFitis.[25]
  • ‡ May be associated with a worse prognosis.[25]
  • Merkel cell carcinoma lymph node metastases is difficult to diagnose with routine stains; use of IHC stains are advised.[25]
  • Arise from the epidermis - very rarely in situ.[26]

DDx:

Images

www:

IHC

Features:

  • CK7 -ve.
  • CK20 +ve (perinuclear dot-like).[27]
  • CAM5.2 +ve (dot-like pattern).
  • CD56 +ve.
  • AE1/AE3 +ve.
  • Merkel cell polyomavirus +ve ~85% of cases.[28]

Others:

  • TTF-1 -ve.
  • NSE +ve.[26]

EM

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).

Notes:

Kaposi sarcoma

See Kaposi sarcoma.

Sebaceous carcinoma

  • AKA sebaceous cell carcinoma.

General

Notes:

Gross

Features:[31]

  • Classically head and neck tumour.
  • Yellow or red (ulcerated) nodule.

Microscopic

Features:[32]

  • Sebaceous differentiation - may be a minor component - key feature.
    • Sebocytes = abundant pale fluffy cytoplasm with vacuolization.
  • Basaloid cells - often dominant.
    • May lead to confusion with basaloid tumours.
  • Nodular or diffuse growth pattern surrounded by a dense fibrous stroma.
  • Infiltrative border - important.
    • The key difference with sebaceous adenoma in cases where there isn't significant nuclear atypia.
  • +/-Nuclear atypia.
  • +/-Squamous differentiation.
  • +/-Foreign body-type giant cells.

DDx:

Images

www:

Grading

Three tier system:[32]

  • Well-differentiated - sebocytes predominant.
  • Moderately differentiated - sebocytes are easily recognized but a minor component.
  • Poorly differentiated - sebocytes are rare.

IHC

Features:[32]

Images:

Sign out

SKIN LESION, NOSE, BIOPSY:
- SEBACEOUS CARCINOMA, WELL-DIFFERENTIATED, COMPLETELY EXCISED IN THE PLANE OF SECTION.

COMMENT:
EMA staining marks the sebocytes.  The lesion is negative for Ber-EP4.

Sebaceous carcinoma may be seen in the context of Muir-Torre syndrome.

Micro

Well differentiated

The sections show well-circumscribed dermal nests of basaloid cells with peripheral palisading, surrounded by a dense fibrous stroma. The basaloid cells have distinct nucleoli. Focally, the basaloid nests contain small clusters of cells with abundant pale, vacuolated, fluffy-appearing cytoplasm (sebocytes). Mitotic activity is minimal.

There is no artefactual clefting between the stroma and basaloid cell nests. The epidermis matures to the surface and does not have basal atypia.

The lesion is completely excised in the plane of section.

Poor differentiated

The sections show well-circumscribed dermal nests of basaloid cells with peripheral palisading, surrounded by a dense fibrous stroma, that extend from the skin surface almost to the adipose tissue. The basaloid cells have moderate nuclear atypia with occasional monstrous cells. Mitotic activity is abundant and atypical mitoses are present. The nests contain rare cells with pale, fluffy-appearing cytoplasm, suggestive of sebocytes.

Microcystic adnexal carcinoma

  • AKA syringomatous carcinoma, AKA sclerosing sweat duct carcinoma.[35]

General

  • Low-grade tumour.
  • Adults.

Microscopic

Features:[36]

  • Small basaloid cells - often forming small cystic spaces - key feature.
    • Very bland cytology.
  • Fibrotic stroma.

DDx:

Image:

IHC

Features:[38]

Trichilemmal carcinoma

General

  • Super rare.
  • Not well-described.

Microscopic

Features:[39]

  • Clear (glycogen-rich) cytoplasm in center of lesion.
  • Peripheral palisading at edge of lesion - root sheath differentiation (hair follicle).
  • Contiguous with hair follicle or assoc. with trichilemmoma.

DDx:

Lymphomatoid papulosis

General

  • Rare.
  • Benign behaviour.

Microscopic

Features:

  • Dermal lymphocytosis.
    • No epidermal lymphocytes.
  • Focal nuclear atypia.

DDx:

IHC

Rare malignant

Basosquamous carcinoma

Should not be confused with basaloid squamous cell carcinoma (AKA squamous cell carcinoma, basaloid variant).

General

Microscopic

Features:

Note:

  • Busam notes that there is disagreement about what defines this tumour;[44] however, he goes on the describe it as a collision tumour.[43]

DDx:

Intermediate

Atypical fibroxanthoma

  • Abbreviated AFX.

General

Clinical:

  • Rapid growth.
  • Elderly.
  • Good prognosis.[49]

Microscopic

Features:[50]

  • Dermal lesion - key point.
  • Marked nuclear atypia.
  • Mitoses.
  • Mulitnucleated cells.
  • Foamy cytoplasm - key feature.

DDx:

Notes:

  • No Grenz zone. (???)

Image:

IHC

Features:[50]

  • S100 -ve (done to r/o melanoma).
  • 34betaE12 -ve.
  • p63 -ve (done to exclude SCC)
    • Scant staining not considered +ve.
  • Desmin -ve (done to r/o leiomyosarcoma).

Benign

Syringoma

General

  • Benign sweat duct tumour.
  • Eccrine differentiation.
  • Usually close to lower eyelid.[52]

Microscopic

Features:[53]

  • Proliferation of benign ducts with lined by a bilayer (as in normal sweat ducts) with abnormal architecture:
    • Tadpole like appearing ducts.

DDx:

Images:

Chondroid syringoma

  • Used to be called mixed tumour of skin.[56]

General

  • Mixed apocrine & eccrine tumour of skin, usually in the head & neck[56], especially nose and cheek.[57]
  • May be in major and minor salivary glands.[57]

Microscopic

Features:

  • Mix tumour with:[56]
    1. Epithelial component:
      • Nests of cells with:
        • Moderate dull eosinophilic cytoplasm.
        • Round/ovoid nuclei with nucleoli.
    2. Mesenchymal component - key feature:

Images:

Dermal cylindroma

General

May be familial:[59]

  • Familial cylindromatosis (autosomal dominant).
  • Brook–Spiegler syndrome.

Gross

  • Classically scalp - usually head and neck or face.

Microscopic

Features:[59]

  • Nests of cells that fit together like a jigsaw puzzle - the borders of the nests are opposed and undulate.
    1. Basaloid cells with scant cytoplasm and dark nuclei palisade around the edge of the nests.
    2. Larger cells with moderate eosinophilic cytoplasm and lighter staining nuclei are at the centre of the nests.
  • Cells nests surrounded by a band of hyaline (i.e. glassy, eosinophilic, acellular) material ~ 2X thickness of a basilar cell - key feature.
    • This is basement membrane.

DDx:

Images

www:

Stains

  • PAS +ve (basement membrane).[59]

Keratoacanthoma

Sebaceous adenoma

General

Notes:

Microscopic

Features:

  • Abnormal sebaceous glands (pale fluffy cytoplasm):
    • Increased basal epithelium.
    • Multiple dilated glands - opening to the surface.

Images

www:

Trichilemmoma

  • May be spelled tricholemmoma.

General

  • Benign neoplasm with features of the pilosebaceous follicular epithelium.[62]
  • Associated with nevus sebaceous.[63]
  • Muliple trichilemmomas associated with Cowden syndrome.[64]

Microscopic

Features:[64]

  • Superficial dermal lesion contiguous with the epidermis:
    • Core of lesion:
      • Cuboidal cells with round nuclei, eosinophilic-clear cytoplasm.
    • Periphery of lesion:
      • Surrounded by hyaline band.
      • Peripheral palisading.

DDx:

Images:

Eccrine poroma

General

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

Microscopic

Features:[67]

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

Notes:

  • Area above gland appears crusted.

DDx:

Images:

Nodular hidradenoma

General

  • Benign adnexal tumour.[69]

Typical locations:[68]

  • Scalp.
  • Face.
  • Trunk, anterior.

Microscopic

Features:[69]

  • Well-circumscribed dermal lesions with:
    • Back-to-back nests with a whorled appearance.
    • Spaces between cells.
    • Nuclei ovoid and centrally placed in the cell.
      • No nucleolus.
    • Cystic spaces with degenerated cells.

DDx:

Images

IHC

Features:[69]

  • CAM5.2 +ve.
  • AE1/AE3 +ve.
  • EMA +ve.
  • S100 -ve.
  • Desmin -ve.

Trichoblastoma

  • AKA trichoepithelioma.
    • Trichoepithelioma is considered a superficial version of trichoblastoma; WHO lumps the two entities together.[70]

General

  • Benign.
  • May be familial:
    • Multiple familial trichoepithelioma.[71]
    • Brooke-Spiegler syndrome.

Microscopic

Features:[72]

  • Well-circumscribed cell nest in the superficial dermis.
  • Surrounding by a fibrous stroma.
  • Basaloid cells with peripheral palisading.
  • +/-Surround keratin-filled cysts.
  • Fibroblasts-like cell aggregate, similar to a follicular papillae (papillary-mesenchymal body).

Notes:

Variants:

  • Desmoplastic trichoblastoma.

DDx:

Images=

www:

Sign out

SKIN LESION, NOSE, BIOPSY:
- TRICHOBLASTOMA, COMPLETELY EXCISED.

Micro

The sections show well-circumscribed dermal nests of basaloid cells with peripheral palisading surrounded by a dense fibrous stroma. There is no artefactual clefting between the stroma and basaloid cell nests. Mitotic activity is minimal. Smaller hyperchromatic spindled-to-epithelioid cells in clusters (papillary-mesenchymal bodies) are found within the basaloid cells nests.

The epidermis show maturation to the surface and does not have basal atypia.

The lesion is completely excised in the plane of section.

Trichofolliculoma

General

  • Benign.

Microscopic

Features:[75]

  • Irregular hair follicle (basilar nest of cells with an acellular hair shaft) with:
    • Smaller satellites (follicles) consisting of well-circumscribed basilar cells.

Note:

  • Lack artificial clefting between the (basilar) nests and stroma (seen in BCC).
  • Surrounding stroma does not have a basophilic tingle (seen in BCC).

DDx:

Images

www:

Apocrine carcinoma of the skin

General

  • Rare.[76]
  • Usually very good prognosis.[76]

Microscopic

Features:[76]

  • Nests.
  • Apocrine snouts - "decapitation secretion"

DDx:

Images

Stains

Features:[76]

  • PAS +ve.
  • PASD +ve.

IHC

  • GCDFP-15 (gross cystic disease fluid protein-15) +ve.[76]

Dermatomyofibroma

Should not be confused with dermatofibroma.
  • Abbreviated DMF.

General

  • Uncommon.

Microscopic

Features:[11]

  • Poorly formed fasicles parallel to the skin surface, usu. restricted to the superficial dermis.
  • Moderate cellular density - less cellular than DFSP.
  • Eosinophilic cytoplasm.

DDx:

Images:

IHC

Features:[11]

  • CD10 +ve.
  • Vimentin +ve.

Others:[11]

  • CD34 -ve.
  • Factor XIIIa -ve.
  • S-100 -ve.

Papillary eccrine adenoma

  • Abbreviated PEA.

General

  • Uncommon.
  • Benign.[77]

Treatment:

Gross

  • Central location.

Note:

  • The digital papillary adenoma is considered malignant; the AFIP says these are best classified as adenocarcinomas, i.e. digital papillary adenocarcinoma.[79]

Microscopic

Features:[80][81]

  • Well-circumscribed lesions consisting of multiple cystic spaces lined by a bilayered epithelium with:
    • Papillary projections into the lumen.
    • Amorphous eosinophilic material in the cystic spaces.
    • Surrounded by a fibrous stroma.[82]

Note:

  • May appear to have more than two cell layers.

DDx:

Image:

IHC

Outer layer of epithelium:[82]

  • SMA-alpha +ve.
  • Keratin 14 +ve.

Inner layer of epithelium:[82]

  • Keratin 8 +ve.

Other stains:[81]

  • Vimentin +ve.
  • CEA +ve.
  • EMA +ve.
  • S-100 +ve.

Sign out

SKIN LESION, LEFT PARIETAL SCALP, BIOPSY:
- PAPILLARY ECCRINE ADENOMA.

Micro

The sections show a well-circumscribed multi-locular superficial dermal lesion with a bilayered epithelium and intracystic papillary projections. The cystic spaces contain amorphous eosinophilic material. The cystic component is surrounded by a dense fibrous stroma with a mixed inflammatory infiltrate, consisting primary of plasma cells and lymphocytes.

There is no significant nuclear atypia and no mitotic activity is appreciated. The overlying epidermis matures appropriately. A granular layer is present.

See also

References

  1. 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.
  2. RS. 17 May 2010.
  3. URL: http://www.cap.org/apps/docs/committees/cancer/cancer_protocols/2011/SkinSquamousCell_11protocol.pdf. Accessed on: 29 March 2012.
  4. Buethe, D.; Warner, C.; Miedler, J.; Cockerell, CJ. (2011). "Focus Issue on Squamous Cell Carcinoma: Practical Concerns Regarding the 7th Edition AJCC Staging Guidelines.". J Skin Cancer 2011: 156391. doi:10.1155/2011/156391. PMC 2990020. PMID 21151529. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2990020/.
  5. RS. May 2010.
  6. URL: http://emedicine.medscape.com/article/1101235-workup#a0721. Accessed on: 2 September 2011.
  7. Nofech-Mozes, S.; Hanna, W.. "Toker cells revisited.". Breast J 15 (4): 394-8. doi:10.1111/j.1524-4741.2009.00743.x. PMID 19601945.
  8. Stacchiotti, S.; Pedeutour, F.; Negri, T.; Conca, E.; Marrari, A.; Palassini, E.; Collini, P.; Keslair, F. et al. (Oct 2011). "Dermatofibrosarcoma protuberans-derived fibrosarcoma: clinical history, biological profile and sensitivity to imatinib.". Int J Cancer 129 (7): 1761-72. doi:10.1002/ijc.25826. PMID 21128251.
  9. 9.0 9.1 Kumar, Vinay; Abbas, Abul K.; Fausto, Nelson; Aster, Jon (2009). Robbins and Cotran pathologic basis of disease (8th ed.). Elsevier Saunders. pp. 1183. ISBN 978-1416031215.
  10. 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. 600. ISBN 978-1416054542.
  11. 11.0 11.1 11.2 11.3 Busam, Klaus J. (2009). Dermatopathology: A Volume in the Foundations in Diagnostic Pathology Series (1st ed.). Saunders. pp. 504. ISBN 978-0443066542.
  12. AP. May 2009.
  13. 13.0 13.1 Abenoza P, Lillemoe T (October 1993). "CD34 and factor XIIIa in the differential diagnosis of dermatofibroma and dermatofibrosarcoma protuberans". Am J Dermatopathol 15 (5): 429–34. PMID 7694515.
  14. 14.0 14.1 Goldblum JR, Tuthill RJ (April 1997). "CD34 and factor-XIIIa immunoreactivity in dermatofibrosarcoma protuberans and dermatofibroma". Am J Dermatopathol 19 (2): 147–53. PMID 9129699.
  15. Kumar, Vinay; Abbas, Abul K.; Fausto, Nelson; Aster, Jon (2009). Robbins and Cotran pathologic basis of disease (8th ed.). Elsevier Saunders. pp. 1249. ISBN 978-1416031215.
  16. URL: http://emedicine.medscape.com/article/1099540-overview. Accessed on: 24 August 2010.
  17. URL: http://emedicine.medscape.com/article/1099540-overview. Accessed on: 24 August 2010.
  18. URL: http://emedicine.medscape.com/article/1098342-overview. Accessed on: 24 August 2010.
  19. 19.0 19.1 Klatt, Edward C. (2006). Robbins and Cotran Atlas of Pathology (1st ed.). Saunders. pp. 385. ISBN 978-1416002741.
  20. Kumar, Vinay; Abbas, Abul K.; Fausto, Nelson; Aster, Jon (2009). Robbins and Cotran pathologic basis of disease (8th ed.). Elsevier Saunders. pp. 1185. ISBN 978-1416031215.
  21. 21.0 21.1 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.
  22. 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.
  23. Feng, H.; Shuda, M.; Chang, Y.; Moore, PS. (Feb 2008). "Clonal integration of a polyomavirus in human Merkel cell carcinoma.". Science 319 (5866): 1096-100. doi:10.1126/science.1152586. PMID 18202256.
  24. 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.
  25. 25.0 25.1 25.2 URL: /2011/SkinMerkelCell_11protocol.pdf http://www.cap.org/apps/docs/committees/cancer/cancer_protocols/2011/SkinMerkelCell_11protocol.pdf. Accessed on: 28 March 2012.
  26. 26.0 26.1 Ferringer, T.; Rogers, HC.; Metcalf, JS. (Feb 2005). "Merkel cell carcinoma in situ.". J Cutan Pathol 32 (2): 162-5. doi:10.1111/j.0303-6987.2005.00270.x. PMID 15606676.
  27. Leech, SN.; Kolar, AJ.; Barrett, PD.; Sinclair, SA.; Leonard, N. (Sep 2001). "Merkel cell carcinoma can be distinguished from metastatic small cell carcinoma using antibodies to cytokeratin 20 and thyroid transcription factor 1.". J Clin Pathol 54 (9): 727-9. PMID 11533085.
  28. Jung, HS.; Choi, YL.; Choi, JS.; Roh, JH.; Pyon, JK.; Woo, KJ.; Lee, EH.; Jang, KT. et al. (Oct 2011). "Detection of Merkel cell polyomavirus in Merkel cell carcinomas and small cell carcinomas by PCR and immunohistochemistry.". Histol Histopathol 26 (10): 1231-41. PMID 21870327.
  29. Gil-Moreno, A.; Garcia-Jiménez, A.; González-Bosquet, J.; Esteller, M.; Castellví-Vives, J.; Martínez Palones, JM.; Xercavins, J. (Mar 1997). "Merkel cell carcinoma of the vulva.". Gynecol Oncol 64 (3): 526-32. PMID 9062165.
  30. 30.0 30.1 URL: http://www.ispub.com/journal/the_internet_journal_of_otorhinolaryngology/volume_9_number_2_11/article/sebaceous_adenocarcinoma_of_the_parotid_gland_a_case_report_and_literature_review.html. Accessed on: 8 September 2011.
  31. Busam, Klaus J. (2009). Dermatopathology: A Volume in the Foundations in Diagnostic Pathology Series (1st ed.). Saunders. pp. 431. ISBN 978-0443066542.
  32. 32.0 32.1 32.2 Busam, Klaus J. (2009). Dermatopathology: A Volume in the Foundations in Diagnostic Pathology Series (1st ed.). Saunders. pp. 431-2. ISBN 978-0443066542.
  33. Ansai, S.; Arase, S.; Kawana, S.; Kimura, T. (Oct 2011). "Immunohistochemical findings of sebaceous carcinoma and sebaceoma: retrieval of cytokeratin expression by a panel of anti-cytokeratin monoclonal antibodies.". J Dermatol 38 (10): 951-8. doi:10.1111/j.1346-8138.2011.01274.x. PMID 21592202.
  34. 34.0 34.1 Sinard, JH. (Jun 1999). "Immunohistochemical distinction of ocular sebaceous carcinoma from basal cell and squamous cell carcinoma.". Arch Ophthalmol 117 (6): 776-83. PMID 10369589.
  35. 35.0 35.1 URL: http://www.dermaamin.com/site/histopathology-of-the-skin/65-m/1926-microcystic-adnexal-carcinoma-.html. Accessed on: 16 September 2011.
  36. Busam, Klaus J. (2009). Dermatopathology: A Volume in the Foundations in Diagnostic Pathology Series (1st ed.). Saunders. pp. 412. ISBN 978-0443066542.
  37. Kirzhner, M.; Jakobiec, FA.; Borodic, G.. "Desmoplastic trichoepithelioma: report of a unique periocular case.". Ophthal Plast Reconstr Surg 28 (5): e121-3. doi:10.1097/IOP.0b013e318245535a. PMID 22366669.
  38. Sellheyer, K.; Nelson, P.; Kutzner, H.; Patel, RM. (Apr 2013). "The immunohistochemical differential diagnosis of microcystic adnexal carcinoma, desmoplastic trichoepithelioma and morpheaform basal cell carcinoma using BerEP4 and stem cell markers.". J Cutan Pathol 40 (4): 363-70. doi:10.1111/cup.12085. PMID 23398472.
  39. Busam, Klaus J. (2009). Dermatopathology: A Volume in the Foundations in Diagnostic Pathology Series (1st ed.). Saunders. pp. 399-400. ISBN 978-0443066542.
  40. URL: http://path.upmc.edu/cases/case513/dx.html. Accessed on: 25 January 2012.
  41. 41.0 41.1 Martin, RC.; Edwards, MJ.; Cawte, TG.; Sewell, CL.; McMasters, KM. (Mar 2000). "Basosquamous carcinoma: analysis of prognostic factors influencing recurrence.". Cancer 88 (6): 1365-9. PMID 10717618.
  42. 42.0 42.1 Bowman, PH.; Ratz, JL.; Knoepp, TG.; Barnes, CJ.; Finley, EM. (Aug 2003). "Basosquamous carcinoma.". Dermatol Surg 29 (8): 830-2; discussion 833. PMID 12859383..
  43. 43.0 43.1 Busam, Klaus J. (2009). Dermatopathology: A Volume in the Foundations in Diagnostic Pathology Series (1st ed.). Saunders. pp. 397. ISBN 978-0443066542.
  44. Busam, Klaus J. (2009). Dermatopathology: A Volume in the Foundations in Diagnostic Pathology Series (1st ed.). Saunders. pp. 372. ISBN 978-0443066542.
  45. URL: http://emedicine.medscape.com/article/1056204-overview. Accessed on 2 September 2011.
  46. Withers, AH.; Brougham, ND.; Barber, RM.; Tan, ST. (Jun 2011). "Atypical fibroxanthoma and malignant fibrous histiocytoma.". J Plast Reconstr Aesthet Surg. doi:10.1016/j.bjps.2011.05.004. PMID 21664889.
  47. Ghazarian, Danny; 16 September 2011.
  48. New, D.; Bahrami, S.; Malone, J.; Callen, JP. (Dec 2010). "Atypical fibroxanthoma with regional lymph node metastasis: report of a case and review of the literature.". Arch Dermatol 146 (12): 1399-404. doi:10.1001/archdermatol.2010.206. PMID 20713774.
  49. Beer, TW.; Drury, P.; Heenan, PJ. (Aug 2010). "Atypical fibroxanthoma: a histological and immunohistochemical review of 171 cases.". Am J Dermatopathol 32 (6): 533-40. doi:10.1097/DAD.0b013e3181c80b97. PMID 20526171.
  50. 50.0 50.1 Busam, Klaus J. (2009). Dermatopathology: A Volume in the Foundations in Diagnostic Pathology Series (1st ed.). Saunders. pp. 521. ISBN 978-0443066542.
  51. Vandergriff, TW.; Reed, JA.; Orengo, IF. (2008). "An unusual presentation of atypical fibroxanthoma.". Dermatol Online J 14 (1): 6. PMID 18319023.
  52. Kumar, Vinay; Abbas, Abul K.; Fausto, Nelson; Aster, Jon (2009). Robbins and Cotran pathologic basis of disease (8th ed.). Elsevier Saunders. pp. 1177. ISBN 978-1416031215.
  53. URL: http://emedicine.medscape.com/article/1059871-diagnosis. Accessed on: 12 May 2010.
  54. Boecker, W.; Junkers, T.; Reusch, M.; Buerger, H.; Korsching, E.; Metze, D.; Decker, T.; Loening, T. et al. (2012). "Origin and differentiation of breast nipple syringoma.". Sci Rep 2: 226. doi:10.1038/srep00226. PMID 22355740.
  55. Nosrati, N.; Coleman, NM.; Hsu, S. (2008). "Axillary syringomas.". Dermatol Online J 14 (4): 13. PMID 18627735.
  56. 56.0 56.1 56.2 Kumar, B. (Jan 2010). "Chondroid syringoma diagnosed by fine needle aspiration cytology.". Diagn Cytopathol 38 (1): 38-40. doi:10.1002/dc.21159. PMID 19693940.
  57. 57.0 57.1 Rauso, R.; Santagata, M.; Tartaro, G.; Filipi, M.; Colella, G.. "Chondroid syringoma: a rare tumor of orofacial region.". Minerva Stomatol 58 (7-8): 383-8. PMID 19633639.
  58. 58.0 58.1 URL: http://www.ispub.com/journal/the_internet_journal_of_dermatology/volume_7_number_2_23/article/cutaneous_mixed_tumor.html. Access on: 21 September 2011.
  59. 59.0 59.1 59.2 59.3 59.4 Obaidat, NA.; Alsaad, KO.; Ghazarian, D. (Feb 2007). "Skin adnexal neoplasms--part 2: an approach to tumours of cutaneous sweat glands.". J Clin Pathol 60 (2): 145-59. doi:10.1136/jcp.2006.041608. PMC 1860616. PMID 16882695. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1860616/.
  60. Gerber, JE.; Descalzi, ME. (Feb 1983). "Eccrine spiradenoma and dermal cylindroma.". J Cutan Pathol 10 (1): 73-8. PMID 6302142.
  61. Lee, MW.; Kelly, JW. (Feb 1996). "Dermal cylindroma and eccrine spiradenoma.". Australas J Dermatol 37 (1): 48-9. PMID 8936072.
  62. URL: http://emedicine.medscape.com/article/1059940-overview. Accessed on: 2 September 2011.
  63. Baykal, C.; Buyukbabani, N.; Yazganoglu, KD.; Saglik, E. (Jan 2006). "[Tumors associated with nevus sebaceous].". J Dtsch Dermatol Ges 4 (1): 28-31. doi:10.1111/j.1610-0387.2006.05855.x. PMID 16503928.
  64. 64.0 64.1 Busam, Klaus J. (2009). Dermatopathology: A Volume in the Foundations in Diagnostic Pathology Series (1st ed.). Saunders. pp. 386. ISBN 978-0443066542.
  65. 65.0 65.1 URL: http://ccr.cancer.gov/staff/gallery.asp?profileid=12822. Accessed on: 2 September 2011.
  66. URL: http://dermatlas.med.jhmi.edu/derm/indexDisplay.cfm?ImageID=667496720. Accessed on: 2 September 2011.
  67. URL: http://www.pathconsultddx.com/pathCon/diagnosis?pii=S1559-8675(06)70190-5. Accessed on: 2 July 2010.
  68. 68.0 68.1 Punia, RP.; Garg, S.; Bal, A.; Mohan, H. (2008). "Pigmented nodular hidradenoma masquerading as nodular malignant melanoma.". Dermatol Online J 14 (1): 15. PMID 18319032.
  69. 69.0 69.1 69.2 Stratigos, AJ.; Olbricht, S.; Kwan, TH.; Bowers, KE. (Mar 1998). "Nodular hidradenoma. A report of three cases and review of the literature.". Dermatol Surg 24 (3): 387-91. PMID 9537017.
  70. Busam, Klaus J. (2009). Dermatopathology: A Volume in the Foundations in Diagnostic Pathology Series (1st ed.). Saunders. pp. 383. ISBN 978-0443066542.
  71. Salhi, A.; Bornholdt, D.; Oeffner, F.; Malik, S.; Heid, E.; Happle, R.; Grzeschik, KH. (Aug 2004). "Multiple familial trichoepithelioma caused by mutations in the cylindromatosis tumor suppressor gene.". Cancer Res 64 (15): 5113-7. doi:10.1158/0008-5472.CAN-04-0307. PMID 15289313.
  72. URL: http://emedicine.medscape.com/article/1060049-workup#a0723. Accessed on: 31 August 2011.
  73. URL: http://emedicine.medscape.com/article/1060049-workup#a0723 Papillary-mesenchymal body (emedicine.medscape.com). Accessed on: 22 August 2012.
  74. URL: http://skinpathologyatlas.com/tumors/hair/trichofollic.htm. Accessed on: 22 August 2012.
  75. Busam, Klaus J. (2009). Dermatopathology: A Volume in the Foundations in Diagnostic Pathology Series (1st ed.). Saunders. pp. 382. ISBN 978-0443066542.
  76. 76.0 76.1 76.2 76.3 76.4 Paties, C.; Taccagni, GL.; Papotti, M.; Valente, G.; Zangrandi, A.; Aloi, F. (Jan 1993). "Apocrine carcinoma of the skin. A clinicopathologic, immunocytochemical, and ultrastructural study.". Cancer 71 (2): 375-81. PMID 7678545.
  77. Rulon, DB.; Helwig, EB. (May 1977). "Papillary eccrine adenoma.". Arch Dermatol 113 (5): 596-8. PMID 857729.
  78. URL: http://archderm.jamanetwork.com/article.aspx?articleid=541159. Accessed on: 10 December 2012.
  79. Duke, WH.; Sherrod, TT.; Lupton, GP. (Jun 2000). "Aggressive digital papillary adenocarcinoma (aggressive digital papillary adenoma and adenocarcinoma revisited).". Am J Surg Pathol 24 (6): 775-84. PMID 10843279.
  80. 80.0 80.1 Laxmisha, C.; Thappa, DM.; Jayanthi, S.. "Papillary eccrine adenoma.". Indian J Dermatol Venereol Leprol 70 (6): 370-2. PMID 17642667.
  81. 81.0 81.1 Guccion, JG.; Patterson, RH.; Nayar, R.; Saini, NB.. "Papillary eccrine adenoma: an ultrastructural and immunohistochemical study.". Ultrastruct Pathol 22 (3): 263-9. PMID 9793207.
  82. 82.0 82.1 82.2 Mizuoka, H.; Senzaki, H.; Shikata, N.; Uemura, Y.; Tsubura, A. (Jan 1998). "Papillary eccrine adenoma: immunohistochemical study and literature review.". J Cutan Pathol 25 (1): 59-64. PMID 9508346.
  83. Fox, SB.; Cotton, DW. (Apr 1992). "Tubular apocrine adenoma and papillary eccrine adenoma. Entities or unity?". Am J Dermatopathol 14 (2): 149-54. PMID 1566975.
  84. Ishiko, A.; Shimizu, H.; Inamoto, N.; Nakmura, K. (Oct 1993). "Is tubular apocrine adenoma a distinct clinical entity?". Am J Dermatopathol 15 (5): 482-7. PMID 8238787.