Pathology

About 75% of cases are pure adenocarcinomas. Occasionally, squamous elements are present. If these are benign, the tumour may be referred to as an adenocanthoma; when malignant, as an adenosquamous carcinoma. The latter carries a poorer prognosis. Rarely, endometrial cancer may be a leiomyosarcoma or a mixed mesodermal tumour.

• histopathological types include:
  • endometrioid carcinoma: adenocarcinoma; adenoacanthoma (adenocarcinoma with squamous metaplasia); and adenosquamous carcinoma (mixed adenocarcinoma and squamous cell carcinoma).
  • mucinous adenocarcinoma
  • serous adenocarcinoma
  • clear cell adenocarcinoma
  • undifferentiated carcinoma
  • mixed carcinoma (carcinoma composed of more than 1 type, with at least 10% of each component) (1).
    
    

Spread is usually by direct extension to adjacent structures. The tumour commonly invades through the myometrium but may also spread downwards into the cervix. Less commonly, it may involve the vagina, rectum or bladder.

Exfoliated cells may pass through the fallopian tubes and deposit on the ovaries, parietal peritoneum, or omentum. Often, it is these secondary growths which result in death.

Lymphatic spread occurs later and is less frequent than seen in cervical cancer. Spread is mainly to the pelvic lymph nodes, and subsequently, to the para-aortic nodes.

Haematogenous spread is rare. Metastases occur most often in the lungs and liver.

Reference:

• (1) Amant F, Mirza MR, Creutzberg CL.Cancer of the corpus uteri. Int J Gynaecol Obstet. 2012;119 Suppl 2:S110-7.