Difference between revisions of "Leiomyosarcoma"

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*Poor prognosis.
*Poor prognosis.
*Do not (generally) arise from leiomyomas.
*Do not (generally) arise from leiomyomas.
*Often singular, i.e. one tumour; unlike leiomyomas (which are often multiple).
*Often singular, i.e. one tumour; unlike [[leiomyoma]]s (which are often multiple).


==Gross==
==Gross==
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*[[Soft tissue lesions]].
*[[Soft tissue lesions]].
*[[Uterine tumours]].
*[[Uterine tumours]].
*[[Leiomyoma]].


==References==
==References==

Revision as of 04:47, 3 June 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):
    1. Cellular atypia - common.
    2. Necrosis.
      • Should be patchy/multifocal.
        • Zonal necrosis is suggestive of vascular cause.
    3. Mitoses - key feature - definitions suffers from HPFitis:
      • 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

  1. 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.