OVARIAN, FALLOPIAN TUBE AND PRIMARY PERITONEAL CARCINOMA (ICD‐O‐3 C56, C57, C48.1, C48.2)

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

Rules for Classification

The classification applies to malignant ovarian neoplasms of both epithelial and stromal origin, including those of borderline malignancy or of low malignant potential corresponding to “common epithelial tumours” of the earlier terminology. The classification also applies to carcinoma of the Fallopian tubes and to carcinomas of the peritoneum (Müllerian origin). There should be histological confirmation of the disease and division of cases by histological type.

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

Schematic illustration of hypogastric, common iliac, external iliac, lateral sacral and para-aortic. — **Fig. 452**

Regional Lymph Nodes (Fig. 452)

The regional lymph nodes are the hypogastric (obturator and internal iliac) (1), common iliac (2), external iliac (3), lateral sacral (4) and para‐aortic (5).

TNM Clinical Classification

T – Primary Tumour

TNM Categories			FIGO Stages	Definition
TX				Primary tumour cannot be assessed
T0				No evidence of primary tumour
T1			I	Tumour confined to the ovaries (one or both) or fallopian tube(s)
	T1a		IA	Tumour limited to one ovary (capsule intact) or fallopian tube; no tumour on ovarian or fallopian tube surface, no malignant cells in ascites or peritoneal washings (Fig. 453)
	T1b		IB	Tumour limited to both ovaries or fallopian tubes (Fig. 454)
	T1c		IC	Tumour limited to one or both ovaries or fallopian tubes with any of the following:
		T1c1		Surgical spill
		T1c2		Capsule ruptured before surgery or tumour on ovarian or fallopian tube surface
		T1c3		Malignant cells in ascites or peritoneal washings (Fig. 455)
T2			II	Tumour involves one or both ovaries or fallopian tubes with pelvic extension (below the pelvic brim) or primary peritoneal cancer
	T2a		IIA	Extension and/or implants on uterus and/or fallopian tube(s) and or ovary(ies) (Fig. 456)
	T2b		IIB	Extension to other pelvic tissues, including bowel within the pelvis (Fig. 457)
T3 and/or N1			III^a	Tumour involves one or both ovaries or fallopian tubes or primary peritoneal carcinoma with cytologically or histologically confirmed spread to the peritoneum outside the pelvis and/or metastasis to the retroperitoneal lymph nodes
N1				Retroperitoneal lymph node metastasis only
	N1a		IIIA1i	Lymph node metastasis not more than 10 mm in greatest dimension (Fig. 458)
	N1b		IIIA1ii	Lymph node metastasis more than 10 mm in greatest dimension (Fig. 458)
T3c and/or N1			IIIA2	Microscopic extrapelvic (above the pelvic brim) peritoneal involvement with or without retroperitoneal lymph node, including bowel involvement (Fig. 459)
T3b any N			IIIB	Macroscopic peritoneal metastasis beyond pelvic brim 2 cm, or less in greatest dimension, including bowel involvement outside the pelvis with or without retroperitoneal nodes (Fig. 459)
T3c any N			IIIC	Peritoneal metastasis beyond pelvic brim more than 2 cm in greatest dimension and/or retroperitoneal lymph node metastasis (includes extension of tumour to capsule of liver and spleen without parenchymal involvement of either organ) (Fig. 459, 460)
M1			IV	Distant metastasis (excludes peritoneal metastasis)
	M1a		IVA	Pleural effusion with positive cytology
	M1b^b		IVB	Parenchymal metastasis and metastasis to extra abdominal organs (including inguinal lymph nodes and lymph nodes outside the abdominal cavity) (Fig. 460)

Note
^aLiver capsule metastasis is T3/stage III.

^bLiver parenchymal metastasis M1/stage IV.

Schematic illustration of tumour limited to one ovary or fallopian tube; no tumour on ovarian or fallopian tube surface, no malignant cells in ascites or peritoneal washings. — **Fig. 453**

Schematic illustration of tumour limited to both ovaries or fallopian tubes. — **Fig. 454**

Schematic illustration of Malignant cells in ascites or peritoneal washings. — **Fig. 455**

Schematic illustration of Extension and implants on uterus and fallopian tube(s) and or ovary(ies). — **Fig. 456**

Schematic illustration of Extension to other pelvic tissues, including bowel within the pelvis. — **Fig. 457**

Schematic illustration of Lymph node metastasis not more than 10 mm in greatest dimension. — **Fig. 458**

Schematic illustration of Microscopic extrapelvic peritoneal involvement with or without retroperitoneal lymph node, including bowel involvement. — **Fig. 459**

Schematic illustration of Peritoneal metastasis beyond pelvic brim more than 2 cm in greatest dimension and retroperitoneal lymph node metastasis. — **Fig. 460**

N – Regional Lymph Nodes

NX	Regional lymph nodes cannot be assessed
N0	No regional lymph node metastasis
N1	Regional lymph node metastasis (Fig. 458)
N1 IIIA1	Retroperitoneal lymph node metastasis only
N1a IIIA1i	Lymph node metastasis no more than 10 mm in greatest dimension
N1b IIIA1ii	Lymph node metastasis more than 10 mm in greatest dimension

M – Distant Metastasis

M0	No distant metastasis
M1	Distant metastasis
M1a	Pleural effusion with positive cytology
M1b	Parenchymal metastasis and metastasis to extra‐abdominal organs (including inguinal lymph nodes and lymph nodes outside the abdominal cavity) (Fig. 460)

pTNM Pathological Classification

The pT and pN categories correspond to the T and N categories.

pM1	Distant metastasis microscopically confirmed
pM1a	Pleural effusion with positive cytology
pM1b	Parenchymal metastasis and metastasis to extra‐abdominal organs (including inguinal lymph nodes and lymph nodes outside the abdominal cavity)

Note
pM0 and pMX are not valid categories.

pN0

Histological examination of a pelvic lymphadenectomy specimen will ordinarily include 6 or more lymph nodes. If the lymph nodes are negative, but the number ordinarily examined is not met, classify as pN0.