Adenosarcoma of the uterus

Adenosarcoma of the uterus is an uncommon tumour that arises from the uterus with benign glands and malignant mesenchymal elements.

General

Features:

• Uncommon.
• May prolapse through cervical os and thus present as cervical polyp.
• Most commonly uterine corpus, occasionally cervix and ovary, rarely in the vagina, fallopian tube, peritoneal surfaces, intestine.
• Typically 30-40 years old.

Clinical:

• Most common presentations of Müllerian adenosarcoma (percentages based on series of 41 individuals):
  • Vaginal bleeding ~ 70%.
  • Pelvic mass ~ 40%.
  • Uterine polyp ~ 30%.
• Prognosis (based on series of ~500 individuals):
  • Favourable outcome - most detected at an early stage.
    • ~80% five year survival for stage I tumours.
  • Outcome better than carcinosarcoma.

Treatment:

• TAH-BSO.
  • Tumours are estrogen responsive.
• Chemotherapy (platin-based).

Microscopic

Features:

• "Malignant stroma" - key feature.
  • Stromal nuclear pleomorphism - usually low grade.
  • WHO criteria: 2+ mitoses / 10 HPF -- definition suffers from HPFitis.
    • Mitotic rate criteria often ignored as mitotically inactive tumours metastasize.
• Benign glands with an abnormal shape.
• "Cambium layer" = increased cellularity around the epithelial elements.

Notes:

• Tumour may vaguely resemble a phyllodes tumour.
• Cambium layer - seen in: adenosarcoma, botryoid RMS.

DDx:

• Benign endometrial polyp.
• Uterine adenofibroma.

Images

• 

  Uterine adenosarcoma - low mag. (WC)

• 

  Uterine adenosarcoma - intermed. mag. (WC)

• 

  Uterine adenosarcoma - high mag. (WC)

IHC

• CD10 +ve.
• ER +ve.
• PR +ve.

See also

• Uterine tumours.