Uterine Cancer (Endometrial Carcinoma): Classification

Histopathological classification of endometrial hyperplasia according to WHO 2014.

New designation Synonyms Genetic modification Synchronous invasive EC (%) Progression to invasive carcinoma
Hyperplasia without atypia
  • Benign endometrial hyperplasia Simple, nonatypical endometrial hyperplasia.
  • Complex, non-atypical endometrial hyperplasia
  • Simple endometrial hyperplasia without atypia.
  • Complex endometrial hyperplasia without atypia
 Low level of somatic mutations in scattered HE morphologically unaltered glands. < 1 RR 1.01-1.03
Atypical hyperplasia/endometrioid intraepithelial neoplasia.
  • Complex atypical endometrial hyperplasia.
  • Simple atypical endometrial hyperplasia
  • Endometrial intraepithelial neoplasia
  • Endometrioid intraepithelial neoplasia (EIN).
 Microsatellite instability, PAX2 inactivation, mutations of PTEN, KRAS, and CTNNB1. 25-59 % RR 14-45

Histopathological classification of endometrial carcinoma (EC) according to WHO 2014.

Tumor typing Further subdivision
Endometrioid adenocarcinoma – –
Endometrioid adenocarcinoma variants.
  • Secretory variant
  • Ciliated cell variant
  • Villoglandular variant
  • Variant with squamous differentiation.
Mucinous adenocarcinoma – –
Serous adenocarcinoma – –
Clear cell adenocarcinoma – –
Mixed carcinoma – –
Undifferentiated carcinoma
  • Monomorphic type
  • Dedifferentiated type
Neuroendocrine tumors
  • Well-differentiated neuroendocrine tumor (carcinoid).
  • Poorly differentiated small cell neuroendocrine carcinoma.
  • Poorly differentiated large cell neuroendocrine carcinoma.
Other – –

TNM/FIGO classification for staging (2010).

TNM stage FIGO Status as of 1. 1. 2010
TX * Primary tumor cannot be assessed
T0 * No evidence of primary tumor
Tis * Carcinoma in situ
T1 I Tumor confined to the corpus uteri
T1a IA* * None or less than half myometrial infiltration
T1b IB* * Tumor infiltrates half or more of the myometrium
T2 II Invasion of the cervical stroma, no spread beyond the uterus* * .
T3 (and/or N1) III Local and/or regional spread
T3a IIIA Serosa and/or adnexal involvement
T3b IIIB Vaginal involvement and/or parametrial involvement
N1 IIIC Metastases in the pelvis, lymph node involvement pelvic and/or para-aortic
IIIC1 Positive pelvic lymph nodes
IIIC2 Positive paraortic lymph nodes, with or without positive pelvic lymph nodes
T4 IVA Infiltration of the bladder and/or rectal mucosa.
M1 IVB Distant metastases, including intra-abdominal metastases (excluding metastases to vagina, pelvic serosa, or adnexa, including metastases to inguinal and intra-abdominal lymph nodes other than paraaortic and/or pelvic lymph nodes)

Legend

  • * FIGO does not include TX, T0, carcinoma in situ.
  • * * involvement of endocervical glands is classified as stage T1/I (no longer stage T2/II).
  • 1 a positive peritoneal cytology should be diagnosed separately and documented without change of stage.
  • 2The presence of bullous edema is not sufficient to classify a tumor as T4.Infiltration of the mucosa of the bladder and/or rectum requires confirmation by biopsy