Difference between revisions of "Leiomyosarcoma"
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==Microscopic== | ==Microscopic== | ||
Features: | Features: | ||
* | *Usu. cellular lesion. | ||
* | *Fasciclar arrangement: | ||
**Whorled look at low power. | **Whorled look at low power. | ||
**Groups of spindle cells cut peripendicular to their long axis adjacent to groups of spindle cells cut in the plane of their long axis. | **Groups of spindle cells cut peripendicular to their long axis adjacent to groups of spindle cells cut in the plane of their long axis. | ||
*Features of malignancy (need all three): | *Features of malignancy (need all three): | ||
*# | *#Nuclear atypia. | ||
*# | *#Tumour cell necrosis. | ||
*#*Should be patchy/multifocal. | *#*Should be patchy/multifocal. | ||
*#**Zonal necrosis is suggestive of vascular cause. | *#**Zonal necrosis is suggestive of vascular cause. | ||
*#Mitoses - '''key feature''' - definitions | *#Mitoses - '''key feature''' - definitions suffer from [[HPFitis]]: | ||
*#*10 mitoses/HPF. | *#*>=10 mitoses/HPF - if spindled.<ref name=Ref_GP281>{{Ref GP|281}}</ref> | ||
*#*5 mitoses/HPF - if epithelioid. | *#*>=5 mitoses/HPF - if epithelioid.<ref name=Ref_GP281>{{Ref GP|281}}</ref> | ||
*#*2 mitoses/HPF - if myxoid. | *#*>=2 mitoses/HPF - if myxoid.<ref name=Ref_GP281>{{Ref GP|281}}</ref> | ||
*#*>=1 mitosis/HPF - if cutaneous.<ref name=pmid21358302>{{cite journal |author=Kraft S, Fletcher CD |title=Atypical intradermal smooth muscle neoplasms: clinicopathologic analysis of 84 cases and a reappraisal of cutaneous "leiomyosarcoma" |journal=Am. J. Surg. Pathol. |volume=35 |issue=4 |pages=599–607 |year=2011 |month=April |pmid=21358302 |doi=10.1097/PAS.0b013e31820e6093 |url=}}</ref> | *#*>=1 mitosis/HPF - if cutaneous.<ref name=pmid21358302>{{cite journal |author=Kraft S, Fletcher CD |title=Atypical intradermal smooth muscle neoplasms: clinicopathologic analysis of 84 cases and a reappraisal of cutaneous "leiomyosarcoma" |journal=Am. J. Surg. Pathol. |volume=35 |issue=4 |pages=599–607 |year=2011 |month=April |pmid=21358302 |doi=10.1097/PAS.0b013e31820e6093 |url=}}</ref> | ||
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**[http://commons.wikimedia.org/wiki/File:Cutaneous_leiomyosarcoma_-_high_mag.jpg Cutaneous leiomyosarcoma - high mag. (WC)]. | **[http://commons.wikimedia.org/wiki/File:Cutaneous_leiomyosarcoma_-_high_mag.jpg Cutaneous leiomyosarcoma - high mag. (WC)]. | ||
===IHC | ===Subtypes=== | ||
Variants:<ref name=Ref_GP284>{{Ref GP|284}}</ref> | |||
*Spindled leiomyosarcoma (leiomyosarcoma NOS) - see above. | |||
*Epithelioid leiomyosarcoma. | |||
*Myxoid leiomyosarcoma. | |||
*Leiomyosarcoma with prominent intravascular growth. | |||
*Leiomyosarcoma with osteoclast-type cells. | |||
*Leiomyosarcoma with clear cells. | |||
*Leiomyosarcoma with xanthoma-type cells. | |||
====Epithelioid leiomyosarcoma==== | |||
Features:<ref name=Ref_GP281>{{Ref GP|281}}</ref> | |||
*>50% epithelial appearance. | |||
*>=5 mitoses/HPF - definition suffers from [[HPFitis]]. | |||
====Myxoid leiomyosarcoma==== | |||
Features:<ref name=Ref_GP281>{{Ref GP|281}}</ref> | |||
*>=2 mitoses/HPF - definition suffers from [[HPFitis]]. | |||
*May have minimal nuclear atypia. | |||
==IHC== | |||
*CD10 -ve (important in the context of uterine lesions -- +ve in [[endometrial stromal sarcoma]]). | *CD10 -ve (important in the context of uterine lesions -- +ve in [[endometrial stromal sarcoma]]). | ||
*Positive for SMC markers. | *Positive for SMC markers. | ||
Revision as of 04:15, 20 December 2011
Leiomyosarcoma is a malignant tumour of smooth muscle. It is seen in various places including the uterus and skin.
General
- Poor prognosis.
- Do not (generally) arise from leiomyomas.
- Often singular, i.e. one tumour; unlike leiomyomas (which are often multiple).
Gross
Features:
- "Fleshy" appearance.
- Necrosis.
- Large size.
- Often singular, i.e. one lesion; leiomyomata are often multiple.
Microscopic
Features:
- Usu. cellular lesion.
- Fasciclar arrangement:
- Whorled look at low power.
- Groups of spindle cells cut peripendicular to their long axis adjacent to groups of spindle cells cut in the plane of their long axis.
- Features of malignancy (need all three):
- Nuclear atypia.
- Tumour cell necrosis.
- Should be patchy/multifocal.
- Zonal necrosis is suggestive of vascular cause.
- Should be patchy/multifocal.
- Mitoses - key feature - definitions suffer from HPFitis:
Images:
- Uterine:
- Cutaneous:
Subtypes
Variants:[3]
- Spindled leiomyosarcoma (leiomyosarcoma NOS) - see above.
- Epithelioid leiomyosarcoma.
- Myxoid leiomyosarcoma.
- Leiomyosarcoma with prominent intravascular growth.
- Leiomyosarcoma with osteoclast-type cells.
- Leiomyosarcoma with clear cells.
- Leiomyosarcoma with xanthoma-type cells.
Epithelioid leiomyosarcoma
Features:[1]
- >50% epithelial appearance.
- >=5 mitoses/HPF - definition suffers from HPFitis.
Myxoid leiomyosarcoma
Features:[1]
- >=2 mitoses/HPF - definition suffers from HPFitis.
- May have minimal nuclear atypia.
IHC
- CD10 -ve (important in the context of uterine lesions -- +ve in endometrial stromal sarcoma).
- Positive for SMC markers.
- Desmin - present in all three types of muscle.
- Caldesmon.
- Smooth muscle myosin.
See also
References
- ↑ 1.0 1.1 1.2 1.3 1.4 Nucci, Marisa R.; Oliva, Esther (2009). Gynecologic Pathology: A Volume in Foundations in Diagnostic Pathology Series (1st ed.). Churchill Livingstone. pp. 281. ISBN 978-0443069208.
- ↑ Kraft S, Fletcher CD (April 2011). "Atypical intradermal smooth muscle neoplasms: clinicopathologic analysis of 84 cases and a reappraisal of cutaneous "leiomyosarcoma"". Am. J. Surg. Pathol. 35 (4): 599–607. doi:10.1097/PAS.0b013e31820e6093. PMID 21358302.
- ↑ Nucci, Marisa R.; Oliva, Esther (2009). Gynecologic Pathology: A Volume in Foundations in Diagnostic Pathology Series (1st ed.). Churchill Livingstone. pp. 284. ISBN 978-0443069208.