Difference between revisions of "Leiomyosarcoma"
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==Microscopic== | ==Microscopic== | ||
Features: | Features: | ||
#Cellular atypia - common. | *Cellular lesion. | ||
#Necrosis. | *Fasicular arrangement: | ||
#*Should be patchy/multifocal. | **Whorled look at low power. | ||
#*Zonal necrosis is suggestive of vascular cause. | **Groups of spindle cells cut peripendicular to their long axis adjacent to groups of spindle cells cut in the plane of their long axis. | ||
#Mitoses - '''key feature'''. | *Features of malignancy (need all three): | ||
#*10 mitoses/HPF. | *#Cellular atypia - common. | ||
#*5 mitoses/HPF - if epithelioid. | *#Necrosis. | ||
#*2 mitoses/HPF - if myxoid. | *#*Should be patchy/multifocal. | ||
#*>=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> | *#**Zonal necrosis is suggestive of vascular cause. | ||
*#Mitoses - '''key feature'''. | |||
*#*10 mitoses/HPF. | |||
*#*5 mitoses/HPF - if epithelioid. | |||
*#*2 mitoses/HPF - if myxoid. | |||
*#*>=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> | |||
===IHC=== | ===IHC=== | ||
Revision as of 17:09, 3 May 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:
- Cellular lesion.
- Fasicular 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):
- Cellular atypia - common.
- Necrosis.
- Should be patchy/multifocal.
- Zonal necrosis is suggestive of vascular cause.
- Should be patchy/multifocal.
- Mitoses - key feature.
- 10 mitoses/HPF.
- 5 mitoses/HPF - if epithelioid.
- 2 mitoses/HPF - if myxoid.
- >=1 mitosis/HPF - if cutaneous.[1]
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
- ↑ 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.