Wednesday, December 24, 2014

Gynecological Tumours Corpus Uteri

1. Rules for Classification

The definitions of the T, N, and M categories correspond to the FIGO stages. Both systems are included for comparison.

The classification applies to carcinomas and malignant mixed mesodermal tumours. There should be histological verification with subdivision by histological type and grading of the carcinomas. The diagnosis should be based on examination of specimens taken by endometrial biopsy.

The following are the procedures for assessing T, N, and M categories:

T categories. Physical examination and imaging including urography and cystoscopy
N categories. Physical examination and imaging including urography
M categories. Physical examination and imaging.

The FIGO stages are based on surgical staging. (TNM stages are based on clinical and/or pathological classification.)

2. Anatomical Subsites

1. Isthmus uteri (C54.0)
2. Fundus uteri (C54.3)

3. Regional Lymph Nodes

The regional lymph nodes are the pelvic (hypogastric [obturator, internal iliac], common and external iliac, parametrial, and sacral) and the para-aortic nodes.

4. TNM Clinical Classification

4.1. T - Primary Tumour

TNM Categories FIGO Stages
Primary tumour cannot be assessed
No evidence of primary tumour
Tis 0 Carcinoma in situ (preinvasive carcinoma)
T1 I Tumour confined to corpus uteri
T1a IA Tumour limited to endometrium
T1b IB Tumour invades less than one half of myometrium
T1c IC Tumour invades one half or more of myometrium
T2 II Tumour invades cervix but does not extend beyond uterus
T2a IIA Endocervical glandular involvement only
T2b IIB Cervical stromal invasion
T3 and/or N1 III Local and/or regional spread as specified in T3a, b, N1, and FIGO IIIA, B, C below
T3a IIIA Tumour involves serosa and/or adnexa (direct extension or metastasis) and/or cancer cells in ascites or peritoneal washings
T3b IIIB Vaginal involvement (direct extension or metastasis)
N1 IIIC Metastasis to pelvic and/or para-aortic lymph nodes
T4 IVA Tumour invades bladder mucosa and/or bowel mucosa

Note: The presence of bullous edema is not sufficient evidence to classify a tumour as T4. The lesion should be confirmed by biopsy.
M1 IVB Distant metastasis (excluding metastasis to vagina, pelvic serosa, or adnexa)

Note: FIGO (2001) recommends that Stage I patients given primary radiation therapy can be clinically classified as follows:
Stage I: Tumour confined to corpus uteri
Stage IA: Length of uterine cavity 8 cm or less
Stage IB: Length of uterine cavity more than 8 cm

4.2. N - Regional Lymph Nodes

NX. Regional lymph nodes cannot be assessed
N0. No regional lymph node metastasis
N1. Regional lymph node metastasis

4.3. M - Distant Metastasis

MX. Distant metastasis cannot be assessed
M0. No distant metastasis
M1. Distant metastasis

5. pTNM Pathological Classification

The pT, pN, and pM categories correspond to the T, N, and M categories.
pN0. Histological examination of a pelvic lymphadenectomy specimen will ordinarily include 10 or more lymph nodes. If the lymph nodes are negative, but the number ordinarily examined is not met, classify as pN0.

6. G Histopathological Grading

For histopathological grading see: Creasman WT, Odicino F, Maisoneuve P, Beller U, Benedet JL, Heintz APM, Ngan HYS, Sideri M, Pecorelli S. FIGO Annual Report on the results of treatment in gynaecological cancer. Vol. 24. Carcinoma of the corpus uteri. J Epidemiol Biostat 2001;6:45-86.

7. Stage Grouping

Stage 0 Tis N0 M0
Stage IA T1a N0 M0
Stage IB T1b N0 M0
Stage IC T1c N0 M0
Stage IIA T2a N0 M0
Stage IIB T2b N0 M0
Stage IIIA T3a N0 M0
Stage IIIB T3b N0 M0
Stage IIIC T1, T2, T3 N1 M0
Stage IVA T4 Any N M0
Stage IVB Any T Any N M1

8. Summary

TNM Corpus Uteri FIGO
Tis In situ 0
T1 Confined to corpus I
T1a Tumour limited to endometrium IA
T1b Less than half of myometrium IB
T1c One half or more of myometrium IC
T2 Invades cervix II
T2a Endocervical glandular only IIA
T2b Cervical stroma IIB
T3 and/or N1 Local or regional as specified below III
T3a Serosa/adnexa/positive peritoneal cytology IIIA
T3b Vaginal involvement IIIB
N1 Regional lymph node metastasis IIIC
T4 Mucosa of bladder/bowel IVA
M1 Distant metastasis IVB