Difference between revisions of "Uterine tumours"

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Revision as of 17:33, 18 May 2010

Endometrial stromal tumours is like water in the sea - very very common. Many hysterectomies are done for 'em... the most common are leiomyomata (AKA fibroids).

Leiomyomas

General

  • Often called "fibroids".
  • Extremely common... 40% of women by age 40.
  • Benign.
    • Can be a cause of AUB (abnormal uterine bleeding).
    • Large & multiple associated with infertility.

Variants

  • Lipoleiomyoma - with adipose tissue.
  • Hypercellular leiomyoma - hypercellularity assoc. with more mutations.[1]
  • Atypical leiomyoma (AKA symplastic leiomyoma) - leiomyoma with nuclear atypia.

Gross

  • Sharply circumscribed.
  • Gray-white.
  • Whorled appearance.

Look for...

  • Haemorrhage.
  • Cystic degeneration.
  • Necrosis.

Microscopy

Look for ...

  • Necrosis (low power) -- suggestive of leiomyosarcoma.
  • Hypercellularity.

IHC

Work-up of suspicious leiomyomas:[2]

  • CD10 (+ve).
  • Ki-67 (-ve).
  • SMA (+ve).
  • Desmin (+ve).

Adenomatoid tumour

General:

  • Grossly mimics leiomyoma.[3]
  • Benign tumour.

Microscopy

Features:

  • Contains small tubulocystic spaces lined by cytologically normal mesothelium.

IHC

  • CK7 +ve. (???)[4]
  • Calretin +ve.

Carcinosarcoma

  • AKA "malignant mixed muellerian tumour" (MMMT)
  • May have differentiation to:
    • Muscle,
    • Cartilage or
    • Bone.
  • Assoc. with previous radiation exposure.
  • Metstasize as adenocarcinoma.

Adenosarcoma

Features:[5]

  • Benign glands with an abnormal shape.

DDx:

  • Benign polyp.

Tx:

  • TAH + BSO.

Leiomyocarcoma

General

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

Gross

  • "Fleshy" appearance.
  • Necrosis.
  • Large size.
  • Often singular, i.e. one lesion; leiomyomata are often multiple.

Microscopic

  1. Cellular atypia - common.
  2. Necrosis.
    • Should be patchy/multifocal.
    • Zonal necrosis is suggestive of vascular cause.
  3. Mitoses - key feature.
    • 10/HPF.
    • 5/HPF - if epithelioid.
    • 2/HPF - if myxoid.

IHC

  • CD10 -ve.
  • Positive for SMC markers.
    • Desmin - present in all three types of muscle.
    • Caldesmon.
    • Smooth muscle myosin.

Smooth muscle tumour of uncertain malignant potential (STUMP)

  • Like PUNLMP and ASCUS - a waffle category... when one isn't sure it is a leiomyoma vs. leiomyosarcoma.
  • Clinical behaviour: usually benign.[6]
  • Can be subclassified into four groups - as per Stanford.

Features associated with recurance:[6]

  • p16+, p53+, nuclear atypia.

Management

  • Long-term follow-up.[6]

Endometrial stromal tumours

Overview

WHO classification:[7]

  • Endometrial stromal nodule - not a tumour.
  • Endometrial stromal sarcoma (ESS), low grade.
  • Undifferentiated endometrial sarcoma

Notes:

  • Some believe in a "high grade ESS"... some don't.[8]

Low grade endometrial stromal sarcoma

Features:

  • Highly cellular Islands with a wavy irregular border.
    • Border has finger-like projections/tongue-like projections.
    • Benign uterine smooth muscle between islands of tumour cells.
  • Epithelioid cells.
  • High NC ratio.
  • Thin blood vessels within islands of cells.
    • Tumour cells pallisade around the vessels.

Notes:

  • Vaguely resembles the stroma of proliferative endometrium.

Undifferentiated endometrial sarcoma

Features:

  1. Marked nuclear atypia.
  2. Mitoses+++.
  3. Poorly differentiated - key feature
    • Looks nothing like low grade endometrial stromal sarcoma.
    • Negative for smooth muscle markers (to exclude leiomyosarcoma).

Notes:

  • Need IHC to diagnose.

DDx:

  • Leiomyosarcoma.
  • Carcinosarcoma.
  • Rhabdomyosarcoma.
  • Melanoma.

References