WHO classification of uterine tumours

The Malignant neoplasms involvingWorld Health Organisation (WHO) classification of tumours of the uterusuterine corpus accountis a commonly used classification system for a significant proportionuterine tumours. It is part of allthe 5^th edition WHO classification of female cancersgenital tumours, published in 2020 ¹.

• precursor lesions
  • endometrial hyperplasia without atypia
  • endometrial atypical hyperplasia / endometrioid intraepithelial neoplasia
• endometrial carcinomacarcinomas: commonest: , >90% of all uterine malignancies
  • endometrioid carcinoma of the uterus: commonest histological type, ~80%subtype
  • papillary serous carcinoma of the uterus: ~15~10%
  • clear cell carcinoma of the uterus: ~1-5.5<10%
  • undifferentiated and dedifferentiated carcinomas: ~2%
  • adenocarcinoma of the uterus with squamous differentiationmixed carcinoma: 0.25-0.5~10%
  • undifferentiatedother endometrial carcinomas: rare (includes mesonephric adenocarcinoma (~1%), mesonephric-like adenocarcinoma, squamous cell carcinoma of the endometrium
    • small cell undifferentiated(<5%), mucinous carcinoma of the endometrium
  ) 
• carcinosarcoma: previously known as a malignant mixed Müllerian tumour (~5% of all uterine malignancies)

Tumour-like lesions

• mixed
  endometrial polyp
• endometrial metaplasia
malignant mixed Mullerian tumour
• Arias-Stella reaction

Mesenchymal tumours of the uterus

• smooth muscle tumours
  • uterine leiomyoma previously known ascarcinosarcoma
  • intravenous leiomyomatosis
  • smooth muscle tumour of the uterusuncertain malignant potential
  • metastasising leiomyoma of the uterus 
  • mixed uterine leiomyosarcoma and endometrial stromal sarcoma
• pure
  • uterine leiomyosarcoma: ~33-50% of sarcomas
  • endometrial stromal sarcomaand related tumours: ~10% of sarcomas 
    • endometrial stromal nodule
    • low-grade endometrial stromal sarcoma
    fibrosarcoma
    • high-grade endometrial stromal sarcoma
    • undifferentiated uterine sarcoma
  • miscellaneous mesenchymal tumours
    • uterine tumour resembling ovarian sex cord tumour
    • perivascular epithelioid cell tumour (PEComa)
    • inflammatory myofibroblastic tumour
    • other mesenchymal tumours of the uterus: rare
    • rhabdomyosarcoma of the uterus (includes vascular tumours, lipomatous tumours, alveolar soft part sarcoma: rare
    • liposarcoma of the uterus, solitary fibrous tumour, nerve sheath tumours, NTRK sarcomas, giant cell tumour: rare
    • angiosarcoma of the uterus: rare)

  Mixed epithelial and mesenchymal tumours

  • adenomyoma
  • atypical polypoid adenomyoma
  • adenosarcoma of the uterus 

  Miscellaneous tumours

  • central primitive neuroectodermal tumour / CNS embryonal tumour
  • germ cell tumours

  Other

  Tumours involving the uterus but classified elsewhere (i.e. not of the uterine corpus)​:

  • gestational trophoblastic tumoursdisease
    • : including gestational choriocarcinoma of uterus
  • uterine lymphoma: rare (primary or secondary)
  • local invasion from other tumours:
    • bladder carcinoma
    • colorectal carcinoma
  • malignancies that are not of the uterus, but can involve the uterus
    • invasion of the uterus by
      • cervicaltubal carcinoma
      • vaginal carcinoma
      • cervical carcinoma
      • colorectal carcinoma
      • cancers from the bladder
  • metastases to the uterus from a non-gynaecological malignancy (rare but if it does occur, it is most commonly breast or stomach ³): rare

  See also

  • uterine smooth muscle tumours of uncertain malignant potential