Difference between revisions of "Soft tissue lesions"

From Libre Pathology
Jump to navigation Jump to search
Line 643: Line 643:
===Microscopic===
===Microscopic===
Comes in three (histologic) flavours:<ref name=Ref_WMSP627>{{Ref WMSP|627}}</ref><ref>{{cite journal |author=Schaal CH, Navarro FC, Moraes Neto FA |title=Primary renal sarcoma with morphologic and immunohistochemical aspects compatible with synovial sarcoma |journal=Int Braz J Urol |volume=30 |issue=3 |pages=210–3 |year=2004 |pmid=15689250 |doi= |url=http://www.brazjurol.com.br/may_june_2004/Schaal_ing_210_213.htm}}</ref>
Comes in three (histologic) flavours:<ref name=Ref_WMSP627>{{Ref WMSP|627}}</ref><ref>{{cite journal |author=Schaal CH, Navarro FC, Moraes Neto FA |title=Primary renal sarcoma with morphologic and immunohistochemical aspects compatible with synovial sarcoma |journal=Int Braz J Urol |volume=30 |issue=3 |pages=210–3 |year=2004 |pmid=15689250 |doi= |url=http://www.brazjurol.com.br/may_june_2004/Schaal_ing_210_213.htm}}</ref>
#Spindle cell sarcoma with features of hemangiopericytoma, i.e. staghorn vessels.
#Spindle cell sarcoma with features of hemangiopericytoma, i.e. [[staghorn vessels]].
#Biphasic synovial sarcoma:
#Biphasic synovial sarcoma:
##Spindle cells with features of hemangiopericytoma.
##Spindle cells with features of hemangiopericytoma.

Revision as of 00:17, 26 April 2012

Soft tissue lesions strike fear in many pathologists as they are uncommon and may be difficult to diagnose. Malignant soft tissue lesions, i.e. cancerous soft tissue lesions, are usually sarcomas. Sarcomas are malignancies derived from mesenchymal tissue.

Introduction

WHO classification of soft tissue lesions/tumours

Morphologic grouping

These include:[1]

  1. Adipocytic tumours.
  2. Fibroblastic/myofibroblastic tumours.
  3. "Fibrohistiocytic" tumours.
  4. Smooth muscle tumours.
  5. Skeletal muscle tumours.
  6. Vascular tumours.
  7. Perivascular (pericytic) tumours.
  8. Chondro-osseous tumours.
  9. Tumours of uncertain differentiation.

Biologic potential grouping

These include:[2]

  1. Benign.
  2. Intermediate (locally aggressive).
  3. Intermediate (rarely metastasizing).
  4. Malignant.

Prevalence

  • All sarcomas are rare buggers.
    • As the classification has been changing over the past years (with more subtypes being recognized/identified) numbers are variable from study-to-study.
  • Once upon a time almost everything was called malignant fibrous histiocytoma; thus, it is listed as a common entity in some publications.

Most common:[3]

  • Liposarcoma.
  • Leiomyosarcoma.

Molecular testing

  • Molecular testing plays an important role in soft tissue pathology.
  • It is generally seen as an adjunct test that:[4]
    • Often is used to confirm the histomorphologic impression/quality control.
    • Frequently has some prognostic significance.
    • May directly affect treatment.

Translocations

Morphohistologic patterns

Name Description DDx Image(s) Other
Storiform, AKA patternless pattern[5] whorled, cartwheel-like arrangement pleomorphic undifferentiated sarcoma, solitary fibrous tumour, dermatofibrosarcoma protuberans, dermatofibroma[6] intermed. mag., very high mag. other ?
Herring bone like herring bone (technique) for climbing a hill in cross country skiing; books on a shelf, where they have partially fallen over -- on the one shelf to the left and the one below to the right fibrosarcoma, synovial sarcoma, MPNST intermed. mag., high mag. other ?
Fasicular the long axis of the (spindle) cells are perpendicular to one another in adjacent bundles of cells leiomyoma, leiomyosarcoma intermed. mag., high mag. other ?
Biphasic nests of cells and stroma synovial sarcoma, DSRCT, alveolar RMS DSRCT - high mag. (WC) other ?

Notes:

  • Memory device: herring bone DDx MSF = MPNST, Synovial sarcoma, Fibrosarcoma.

Grading

  • Several systems exist.
  • The US-CAP advocates the use of the French system over the NCI system.
    • The French system is a better predictor metastases and mortality.[7]

French system

  • Formally known as the grading system from the French Federation of Cancer Centres Sarcoma Group (FNCLCC).

Overview

Components - overview:[7][8]

  1. Differentiation (score 1-3).
    • De facto, this is mostly the histologic type.
  2. Mitotic rate (score 1-3).
  3. Necrosis (score 0-2)

Obtaining a score:

  • Add all the points from the three components.

Scoring:

  • Grade 1 = 2-3.
  • Grade 2 = 4-5.
  • Grade 3 = 6-8.
Differentiation
  • Standardized for histologic types.
  • Most tumours = 3/3.

Exceptions:[8]

A group of tumours is not graded:[8]

Mitotic rate
  • 0-9 mitoses/10 HPF.
  • 10-19 mitoses/10 HPF.
  • >=20 mitoses/10 HPF.

Notes:

  • 1 HPF = 0.1734 mm^2.
    • Most resident microscopes have a field of view = 0.2376 mm^2.
      • Thus, ~7.3 HPFs on a resident microscope corresponds to 10 US-CAP HPFs.
Necrosis
  • None = score 0.
  • <=50% of tumour = score 1.
  • >50% of tumour = score 2.

System used by some at MSH

Some pathologists at MSH use the system advocated by Costa et al..[9]

Scoring

  • Grade 1 = 1 point.
  • Grade 2 = 2 points.
  • Grade 3 = 3-4 points.

Components

Points for each of the following:

  • Mitotic activity >= 6 / 10 HPF @ 40X - definition suffers from HPFitis.
  • Pleomorphism present.
  • Cellularity (cells/matrix) > 50%.
  • Necrosis >15% - microscopic (without targeting necrosis grossly) or grossly.

Stage

Lymph node metastases in sarcomas

Sarcomas more likely to be found in the lymph nodes - mnemonic RACE For MS:[12]

DDx by history/site

Retroperiteum

  1. Liposarcoma.
  2. Undifferentiated pleomorphic sarcoma.
  3. Leiomyosarcoma.
  4. MPNST.

Note: Synovial sarcoma and fibrosarcoma are very rare in the retroperitoneum.

Young person - extremity sarcoma

  1. Epithelioid sarcoma.
  2. Synovial sarcoma.

Gross characteristics

  • Usually non-specific.
  • Most sarcomas have a pushing border.
    • If there is an infiltrative border think: (1) fibromatosis, (2) carcinoma.

Adipocytic tumours

This category includes:

  • Lipoma.
  • Liposarcoma.
  • Hibernoma.

Smooth muscle tumours

IHC markers: desmin, SMA, H-caldemsin (most specific).

Leiomyosarcoma

Microscopic

Features (summary):

  • Fasicular cellular spindle cell lesion with:
    • Nuclear atypia.
    • Necrosis.
    • High mitotic rate.

Fibrohistiocytic tumours

Fibrohistiocytic refers (only) to the histomorphologic appearance and therefore may be written in quotation marks; these tumours are not derived from histiocytes (or tissue macrophages), as the name implies.[13]

Pleomorphic undifferentiated sarcoma

  • Abbreviated PUS.
  • AKA Undifferentiated pleomorphic sarcoma, abbreviated UPS.
  • Previously known as malignant fibrous histiocytoma, abbreviated MFH.[14]

General

  • Common sarcoma.
  • Usually deep tissue of the trunk and extremities.
  • A diagnosis of exclusion[15] / wastebasket for unclassifiable high grade sarcomas.

Microscopic

Features:[16]

  • Storiform pattern (AKA patternless pattern) - key feature.
  • Marked nuclear pleomorphism key feature.
    • Variation is nuclear size, nuclear shape and nuclear staining (esp. hyperchromasia).
  • Mitoses - abundant; atypical mitoses common.
  • Necrosis (common).
  • Mix of spindle cells and epithelioid cells.
  • Deep to skin - important.

Other findings:

  • +/-Giant cells (see subclassification).
  • +/-Inflammation (see subclassification).
    • Neutrophils.
    • Eosinophils.

Notes:

DDx:

Images:

Subclassification

Pleomorphic sarcoma (PS) is subclassified the following way:[17]

  • PS with giant cells.
  • PS with inflammation.
  • PUS (not otherwise specified) - wastebasket diagnosis; if neither of the above two apply.

Fibroblastic/myofibroblastic tumours

This is a very large and important group of soft tissue lesions. It is covered in a separate article.

The grouping includes:

Perivascular tumours

This grouping includes only two:[18]

Vascular lesions

Vascular lesions are "too red"; they have too many RBCs.

They include:

Skeletal muscle tumours

Rhabdomyoma

Rhabdomyosarcoma

  • Abbreviated RMS.

Comes it two main flavours:

  • Alveolar rhabdomyosarcoma.
  • Embryonal rhabdomyosarcoma.

The histology may be that of a small round cell tumour.

Chondro-osseous tumours

This grouping includes tumours derived from cartilage and bone.

Tumours of uncertain differentiation

Angiomatoid fibrous histiocytoma

General

  • Rarely metastasizes.
  • Children & young adults.

Microscopic

Features:[19]

  • Cystic spaces with blood - simulates a vascular neoplasm.[20]
  • Epithelioid to spindle cells
    • May have a histiocytic appearance.[21]
  • Inflammation.
    • Lymphoid cuff[22] - lymphocytes around periphery of lesion.
  • Hemorrhage.

Images:

IHC

Features:[19]

  • CD68 +ve.
  • CD57 +ve.
  • Desmin +ve.
  • Vimentin +ve.

Molecular

AFH has recurrent translocations:

  • t(12;16) FUS/ATF1.
  • t(12;22) EWS/ATF1.

Aggressive angiomyxoma

  • AKA deep aggressive angiomyxoma.

General

  • Classically a vulvar mass or (less commonly) a scrotal mass.
    • Case report of a thigh lesion.[23]
  • Benign - no metastatic potential.
  • "Aggressive" as it has a high recurrance.

Microscopic

Features:[24]

  1. Thick blood vessels that meld into the surrounding stroma - key feature.
  2. Myxoid stroma - key feature.
  3. Small stellate cell/spindle cells without significant nuclear atypia.

DDx:

Images:

IHC

Features:[24]

  • Desmin +ve.
  • Vimentin +ve.
  • ER +ve.
  • PR +ve.

Angiomyofibroblastoma

General

  • Uncommon.

Clinical DDx:

Microscopic

Features:[25]

  • Hypercellular zones and hypocellular edematous zones.
  • Small blood vessels (~20 micrometers) - no large blood vessels - key feature.
  • Myxoid stroma - key feature.
  • Small stellate cell/spindle cells without significant nuclear atypia.

DDx:

Images:

Extrarenal malignant rhabdoid tumour

General

Microscopic

Features:[26]

  • Variable architecture.
  • Round cells.
  • Eccentric vesicular nucleus.
  • Prominent nucleolus -- key feature.

IHC

  • INI1 (SMARCB1) -ve.
    • AKA BAF47.

Ewing sarcoma/PNET

Epithelioid sarcoma

General

  • Rare.
  • Adolescents, young adults.

Subclassification:[27]

  • Proximal type:
    • More aggressive.
  • Distal type:

Microscopic

Features:[28]

  • Epithelioid morphology and spindle morphology - which predominates is dependent on location (see subclassification).
  • +/-Prominent nucleolus - distinctive feature.
  • Zonal necrosis with irregular border.
    • Descriptors: "Garland necrosis", necrosis with "scalloped border" = necrotic regions with irregular border.

Subclassification:[27]

  • Proximal-type (proximal location):
    • More epithelioid.
  • Distal-type (distal location):
    • More spindled.
    • Granuloma-like pattern.

DDx:

Images:

IHC

Features:[29]

  • INI1 (SMARCB1[30]) -ve.[31]
  • Vimentin +ve.
  • Various keratins +ve.
    • Keratin 8, Keratin 19 +ve.
    • 34betaE12 +ve/-ve.
  • CD34 +ve.
    • Malignant rhabdoid tumour -ve.

Others:

  • S100 -ve (r/o melanoma).
  • CK7 +ve / CK20 -ve.[32]

Alveolar soft part sarcoma

  • Abbreviated ASPS.

General

  • Adolescents/young adults.
  • Children -- classically location: base of tongue and orbit.
  • Typical indolent initially - ultimately a poor prognosis.[33]

Microscopic

Features:[26]

  • Arranged in nest/separated by thin septa; vaguely resembles alveoli (at low power).
  • Large cells (~30-50 μm) with abundant eosinophilic cytoplasm.
  • An eccentric nucleus.
  • +/-Nucleolus.

DDx:

Images:

Stains

  • PAS +ve (cytoplasmic) - considered the most useful.[34]
  • PASD +ve (cytoplasmic).

IHC

  • TFE3 +ve -- suggestive of characteristic translocation.

Molecular

  • t(X;17)(p11.2;q25).[35]

EM

  • Distinctive membrane-bound intracytoplasmic crystal lattice with ~5 nm fibres spaced 10 nm apart.[33]

Image:

Desmoplastic small round cell tumour

  • Abbreviated DSRCT.

General

  • Males > females.
  • Usu. affects young adults.
  • Typically retroperitoneal.
  • Poor prognosis.

Microscopic

Features:[36]

  1. Broad bands of paucicellular fibrous stroma with:
  2. Small round cells in nests with an undulating sharp border.

Notes:

  • Usu. abundant mitoses.
  • +/-Necrosis.

Images:

DDx:

  • Metastatic germ cell tumour (DDx of location and age).
  • Embryonal RMS.
    • It should be noted that DSRCT, like embryonal RMS, is +ve for desmin!
  • Solid variant of alveolar RMS.
    • Nests in alveolar RMS have round edges.

IHC

Features:

  • AE1/AE3 +ve.
  • Desmin +ve.
  • EMA +ve.
  • Actin -ve.
  • WT1 (N-terminal) -ve.
  • WT1 (C-terminal) +ve.
  • CD57 +ve.

Molecular

Clear cell sarcoma

  • Known among pathologists as "soft-tissue melanoma" and "melanoma of the soft parts", as it has a strong morphological resemblance.[39]
  • Not to be confused with clear cell sarcoma of the kidney.

General

  • Molecular changes and origin distinct from malignant melanoma.
  • Incidence: rare soft tissue tumour.

Clinical

  • Usually - deep soft tissue or extremities.
    • Classically associated with tendons and aponeuroses.[40]
  • Guarded prognosis.
  • First described in 1965.[41]

Microscopic

Features:[39]

  • Architecture: sheets or fascicular (bundles) arrangement.
  • Cells: Spindle cells or epithelioid cells.
  • Prominent nucleoli - basophilic - key feature.
  • Fibrous septae.
  • Uniform.
  • +/-Binucleation.

DDx:

Image:

IHC

Features:[39]

  • S100 +ve.
  • HMB-45 +ve.
  • Melan A (MART-1) +ve; sometimes -ve.
  • BCL2 +ve.
  • CD57 +ve (usually).

Keratins:

  • EMA may be +ve.
  • CAM5.2 -ve.
  • AE1/AE3 -ve.

Molecular studies

Synovial sarcoma

  • Abbreviated SS.

General

  • Does not arise from cartilage.[26]
  • Young adults or adolescents.
    • Classic age: 30s.
  • Poor prognosis.

Clinical:[43]

  • Present with soft palpable mass - slow growing - often for years.
  • May present with pain.
    • Uncommon finding in sarcomas.

Gross

Location:

  • Usually close to a joint.
  • Usually distal extremity ~65% of cases.[43]
    • Upper extremity ~20% of cases.[43]

Appearance - often non-specific:

  • Solid often lobulated +/- cystic component.
  • Grey-yellow.
  • Pushing border to ill-defined border.

Images:

Microscopic

Comes in three (histologic) flavours:[26][45]

  1. Spindle cell sarcoma with features of hemangiopericytoma, i.e. staghorn vessels.
  2. Biphasic synovial sarcoma:
    1. Spindle cells with features of hemangiopericytoma.
    2. Epitheliod glands or nests.
  3. Primitive round cell type.

Features:

DDx:

Images:

IHC

Features:[26]

  • Vimentin +ve.
  • EMA +ve.
  • BCL2 +ve.
  • CD99 +ve.

Others:

  • Beta-catenin +ve ~30-70%.[46]
  • Cyclin D1 ~50%.[46][47]
  • TLE1 +ve nuclear staining; not specific for synovial sarcoma.[48][49]

Typically negative:[50]

  • CD34.
  • S100 ~30% +ve.
  • SMA.

Notes:

  • Synovial sarcoma & MPNST:
    • Both +ve: PGP9.5 (UCHL1[51]), S100, NGFR, CD56, CD99, vimentin.
    • Synovial +ve: EMA, keratin, BCL2, TLE1.
    • MPNST +ve: nestin, CD34.

Trivia:

  • PGP in PGP9.5 = protein gene product.[52]

Molecular pathology

Associated translocation:

  • t(X;18)(p11.2;q11.2).[53]
    • SYT/SSX fusion gene.

Several SSX genes:

  • SSX1.
  • SSX2 - better survival
  • SSX4 - uncommon.

Notes:

  • At HSC t(X,18) = synovial sarcoma.

Other

Granulocytic sarcoma

  • Common alternate terms: myeloid sarcoma, chloroma.
  • Other terms:[54] myeloblastoma, chloromyeloma, chloromyelosarcoma, granulocytic leukosarcoma, or myelosarcoma.

General

  • Soft tissue manifestation of acute myeloid leukemia.[54]

Microscopic

Features:

Note:

Images:

See also

References

  1. Humphrey, Peter A; Dehner, Louis P; Pfeifer, John D (2008). The Washington Manual of Surgical Pathology (1st ed.). Lippincott Williams & Wilkins. pp. 601-3. ISBN 978-0781765275.
  2. Humphrey, Peter A; Dehner, Louis P; Pfeifer, John D (2008). The Washington Manual of Surgical Pathology (1st ed.). Lippincott Williams & Wilkins. pp. 598-604. ISBN 978-0781765275.
  3. Skubitz KM, D'Adamo DR (November 2007). "Sarcoma". Mayo Clin. Proc. 82 (11): 1409–32. PMID 17976362. http://www.mayoclinicproceedings.com/content/82/11/1409.long.
  4. Fletcher CD, Fletcher JA, Dal Cin P, Ladanyi M, Woodruff JM (July 2001). "Diagnostic gold standard for soft tissue tumours: morphology or molecular genetics?". Histopathology 39 (1): 100–3. PMID 11454050.
  5. Mangano WE, Cagle PT, Churg A, Vollmer RT, Roggli VL (August 1998). "The diagnosis of desmoplastic malignant mesothelioma and its distinction from fibrous pleurisy: a histologic and immunohistochemical analysis of 31 cases including p53 immunostaining". Am. J. Clin. Pathol. 110 (2): 191–9. PMID 9704618.
  6. Meister P, Höhne N, Konrad E, Eder M (July 1979). "Fibrous histiocytoma: an analysis of the storiform pattern". Virchows Arch A Pathol Anat Histol 383 (1): 31–41. PMID 224569.
  7. 7.0 7.1 Guillou L, Coindre JM, Bonichon F, et al. (January 1997). "Comparative study of the National Cancer Institute and French Federation of Cancer Centers Sarcoma Group grading systems in a population of 410 adult patients with soft tissue sarcoma". J. Clin. Oncol. 15 (1): 350–62. PMID 8996162.
  8. 8.0 8.1 8.2 URL: http://www.cap.org/apps/docs/committees/cancer/cancer_protocols/2011/SoftTissue_11protocol.pdf. Accessed on: 12 April 2011.
  9. Costa J, Wesley RA, Glatstein E, Rosenberg SA (February 1984). "The grading of soft tissue sarcomas. Results of a clinicohistopathologic correlation in a series of 163 cases". Cancer 53 (3): 530–41. PMID 6692258.
  10. 10.0 10.1 Fong, Y.; Coit, DG.; Woodruff, JM.; Brennan, MF. (Jan 1993). "Lymph node metastasis from soft tissue sarcoma in adults. Analysis of data from a prospective database of 1772 sarcoma patients.". Ann Surg 217 (1): 72-7. PMC 1242736. PMID 8424704. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1242736/.
  11. URL: http://www.cap.org/apps/docs/committees/cancer/cancer_protocols/2011/SoftTissue_11protocol.pdf. Accessed on: 28 March 2012.
  12. URL: http://www.aippg.net/forum/f21/surgery-mnemonics-79897/. Accessed on: 23 March 2012.
  13. Luzar, B.; Calonje, E. (Jan 2010). "Cutaneous fibrohistiocytic tumours - an update.". Histopathology 56 (1): 148-65. doi:10.1111/j.1365-2559.2009.03447.x. PMID 20055912.
  14. URL: http://sarcomahelp.org/learning_center/mfh.html. Accessed on: 8 April 2011.
  15. Matushansky I, Charytonowicz E, Mills J, Siddiqi S, Hricik T, Cordon-Cardo C (August 2009). "MFH classification: differentiating undifferentiated pleomorphic sarcoma in the 21st Century". Expert Rev Anticancer Ther 9 (8): 1135–44. doi:10.1586/era.09.76. PMC 3000413. PMID 19671033. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3000413/.
  16. Humphrey, Peter A; Dehner, Louis P; Pfeifer, John D (2008). The Washington Manual of Surgical Pathology (1st ed.). Lippincott Williams & Wilkins. pp. 613. ISBN 978-0781765275.
  17. Humphrey, Peter A; Dehner, Louis P; Pfeifer, John D (2008). The Washington Manual of Surgical Pathology (1st ed.). Lippincott Williams & Wilkins. pp. 613-4. ISBN 978-0781765275.
  18. Humphrey, Peter A; Dehner, Louis P; Pfeifer, John D (2008). The Washington Manual of Surgical Pathology (1st ed.). Lippincott Williams & Wilkins. pp. 602. ISBN 978-0781765275.
  19. 19.0 19.1 Humphrey, Peter A; Dehner, Louis P; Pfeifer, John D (2008). The Washington Manual of Surgical Pathology (1st ed.). Lippincott Williams & Wilkins. pp. 624-5. ISBN 978-0781765275.
  20. Enzinger, FM. (Dec 1979). "Angiomatoid malignant fibrous histiocytoma: a distinct fibrohistiocytic tumor of children and young adults simulating a vascular neoplasm.". Cancer 44 (6): 2147-57. PMID 228836.
  21. URL: http://dermatology.cdlib.org/1605/1_case_reports/4_09-00041/patrizi.html. Accessed on: 15 November 2011.
  22. 22.0 22.1 Matsumura, T.; Yamaguchi, T.; Tochigi, N.; Wada, T.; Yamashita, T.; Hasegawa, T. (Feb 2010). "Angiomatoid fibrous histiocytoma including cases with pleomorphic features analysed by fluorescence in situ hybridisation.". J Clin Pathol 63 (2): 124-8. doi:10.1136/jcp.2009.072256. PMID 20154033. http://jcp.bmj.com/content/63/2/124.full.
  23. Heffernan, EJ.; Hayes, MM.; Alkubaidan, FO.; Clarkson, PW.; Munk, PL. (Jul 2008). "Aggressive angiomyxoma of the thigh.". Skeletal Radiol 37 (7): 673-8. doi:10.1007/s00256-008-0465-0. PMID 18338163.
  24. 24.0 24.1 Humphrey, Peter A; Dehner, Louis P; Pfeifer, John D (2008). The Washington Manual of Surgical Pathology (1st ed.). Lippincott Williams & Wilkins. pp. 624. ISBN 978-0781765275.
  25. 25.0 25.1 Fletcher, CD.; Tsang, WY.; Fisher, C.; Lee, KC.; Chan, JK. (Apr 1992). "Angiomyofibroblastoma of the vulva. A benign neoplasm distinct from aggressive angiomyxoma.". Am J Surg Pathol 16 (4): 373-82. PMID 1314521.
  26. 26.0 26.1 26.2 26.3 26.4 26.5 26.6 Humphrey, Peter A; Dehner, Louis P; Pfeifer, John D (2008). The Washington Manual of Surgical Pathology (1st ed.). Lippincott Williams & Wilkins. pp. 627. ISBN 978-0781765275.
  27. 27.0 27.1 Guillou L, Wadden C, Coindre JM, Krausz T, Fletcher CD (February 1997). ""Proximal-type" epithelioid sarcoma, a distinctive aggressive neoplasm showing rhabdoid features. Clinicopathologic, immunohistochemical, and ultrastructural study of a series". Am. J. Surg. Pathol. 21 (2): 130–46. PMID 9042279.
  28. The International Agency for Research on Cancer (Editors: Fletcher, C.D.M.; Unni, K. Krishnan; Mertens, F.) (2006). Pathology and Genetics of Tumours of Soft Tissue and Bone (IARC WHO Classification of Tumours) (3rd ed.). World Health Organization. pp. 205. ISBN 978-9283224136.
  29. Miettinen M, Fanburg-Smith JC, Virolainen M, Shmookler BM, Fetsch JF (August 1999). "Epithelioid sarcoma: an immunohistochemical analysis of 112 classical and variant cases and a discussion of the differential diagnosis". Hum. Pathol. 30 (8): 934–42. PMID 10452506.
  30. Online 'Mendelian Inheritance in Man' (OMIM) 601607
  31. Mentzel T (March 2010). "[Epithelioid sarcoma: morphologic variants and differential diagnosis]" (in German). Pathologe 31 (2): 135–41. doi:10.1007/s00292-009-1250-0. PMID 19997734.
  32. Humble, SD.; Prieto, VG.; Horenstein, MG. (Apr 2003). "Cytokeratin 7 and 20 expression in epithelioid sarcoma.". J Cutan Pathol 30 (4): 242-6. PMID 12680954.
  33. 33.0 33.1 33.2 Folpe, AL.; Deyrup, AT. (Nov 2006). "Alveolar soft-part sarcoma: a review and update.". J Clin Pathol 59 (11): 1127-32. doi:10.1136/jcp.2005.031120. PMC 1860509. PMID 17071801. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1860509/.
  34. Zarrin-Khameh, N.; Kaye, KS. (Mar 2007). "Alveolar soft part sarcoma.". Arch Pathol Lab Med 131 (3): 488-91. doi:10.1043/1543-2165(2007)131[488:ASPS]2.0.CO;2. PMID 17516754.
  35. Online 'Mendelian Inheritance in Man' (OMIM) 606243
  36. Pickhardt PJ, Fisher AJ, Balfe DM, Dehner LP, Huettner PC (March 1999). "Desmoplastic small round cell tumor of the abdomen: radiologic-histopathologic correlation". Radiology 210 (3): 633–8. PMID 10207460. http://radiology.rsna.org/content/210/3/633.full.
  37. Lee YS, Hsiao CH (October 2007). "Desmoplastic small round cell tumor: a clinicopathologic, immunohistochemical and molecular study of four patients". J. Formos. Med. Assoc. 106 (10): 854–60. doi:10.1016/S0929-6646(08)60051-0. PMID 17964965.
  38. Lal DR, Su WT, Wolden SL, Loh KC, Modak S, La Quaglia MP (January 2005). "Results of multimodal treatment for desmoplastic small round cell tumors". J. Pediatr. Surg. 40 (1): 251–5. doi:10.1016/j.jpedsurg.2004.09.046. PMID 15868593. http://www.dsrct.com/JPS%20Article.pdf.
  39. 39.0 39.1 39.2 39.3 Hisaoka M, Ishida T, Kuo TT, et al. (March 2008). "Clear cell sarcoma of soft tissue: a clinicopathologic, immunohistochemical, and molecular analysis of 33 cases". Am. J. Surg. Pathol. 32 (3): 452–60. doi:10.1097/PAS.0b013e31814b18fb. PMID 18300804.
  40. Dim, DC.; Cooley, LD.; Miranda, RN. (Jan 2007). "Clear cell sarcoma of tendons and aponeuroses: a review.". Arch Pathol Lab Med 131 (1): 152-6. doi:10.1043/1543-2165(2007)131[152:CCSOTA]2.0.CO;2. PMID 17227118.
  41. URL: http://www.informaworld.com/smpp/723576818-750600/ftinterface~db=all~content=a789166263~fulltext=713240928. Accessed on: 5 May 2010.
  42. Suzuki, K.; Matsui, Y.; Endo, K.; Kubo, T.; Hasegawa, T.; Kimura, T.; Ohtani, O.; Yasui, N. (Nov 2010). "Myxoid liposarcoma with EWS-CHOP type 1 fusion gene.". Anticancer Res 30 (11): 4679-83. PMID 21115923.
  43. 43.0 43.1 43.2 Murphey, MD.; Gibson, MS.; Jennings, BT.; Crespo-Rodríguez, AM.; Fanburg-Smith, J.; Gajewski, DA.. "From the archives of the AFIP: Imaging of synovial sarcoma with radiologic-pathologic correlation.". Radiographics 26 (5): 1543-65. doi:10.1148/rg.265065084. PMID 16973781.
  44. URL: http://www.sarcomaimages.com/index.php?v=Synovial-Sarcoma. Accessed on: 2 April 2012.
  45. Schaal CH, Navarro FC, Moraes Neto FA (2004). "Primary renal sarcoma with morphologic and immunohistochemical aspects compatible with synovial sarcoma". Int Braz J Urol 30 (3): 210–3. PMID 15689250. http://www.brazjurol.com.br/may_june_2004/Schaal_ing_210_213.htm.
  46. 46.0 46.1 Horvai AE, Kramer MJ, O'Donnell R (June 2006). "Beta-catenin nuclear expression correlates with cyclin D1 expression in primary and metastatic synovial sarcoma: a tissue microarray study". Arch. Pathol. Lab. Med. 130 (6): 792–8. PMID 16740029.
  47. Ng TL, Gown AM, Barry TS, et al. (January 2005). "Nuclear beta-catenin in mesenchymal tumors". Mod. Pathol. 18 (1): 68–74. doi:10.1038/modpathol.3800272. PMID 15375433.
  48. Kosemehmetoglu K, Vrana JA, Folpe AL (July 2009). "TLE1 expression is not specific for synovial sarcoma: a whole section study of 163 soft tissue and bone neoplasms". Mod. Pathol. 22 (7): 872–8. doi:10.1038/modpathol.2009.47. PMID 19363472. http://www.nature.com/modpathol/journal/v22/n7/full/modpathol200947a.html.
  49. Seo SW, Lee H, Lee HI, Kim HS (February 2011). "The role of TLE1 in synovial sarcoma". J Orthop Res. doi:10.1002/jor.21318. PMID 21319215.
  50. URL: http://path.upmc.edu/cases/case292/dx.html. Accessed on: 14 January 2012.
  51. Online 'Mendelian Inheritance in Man' (OMIM) 191342
  52. Doran, JF.; Jackson, P.; Kynoch, PA.; Thompson, RJ. (Jun 1983). "Isolation of PGP 9.5, a new human neurone-specific protein detected by high-resolution two-dimensional electrophoresis.". J Neurochem 40 (6): 1542-7. PMID 6343558.
  53. URL: http://www.ncbi.nlm.nih.gov/omim/300813. Accessed on: 30 May 2010.
  54. 54.0 54.1 Eom, KS.; Kim, TY. (Mar 2011). "Intraparenchymal myeloid sarcoma and subsequent spinal myeloid sarcoma for acute myeloblastic leukemia.". J Korean Neurosurg Soc 49 (3): 171-4. doi:10.3340/jkns.2011.49.3.171. PMC 3085814. PMID 21556238. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3085814/.